Table of contents

The 7^th International Conference on Advances in Machinery, Material Science and Engineering Application (MMSE 2021) is organized by the China University of Geosciences (Wuhan) and the Supmeca/Paris School of Mechanical and Manufacturing Engineering, co-organized by the Henan Polytechnic University and the the National University of Singapore, which is planned to be held in Hangzhou, China. However, due to current situation of COVID-19 in China, it is still difficult to take international travel for the attendees abroad. For the sake of protecting all the participants and conference staff from the current situation, the MMSE 2021 is changed to be held virtually through Zoom on July 24-25th 2021.

More than 85 participants from academic, high-education institutes and other organizations attend this online conference from home and abroad, such as Prof. E. Bayraktar from the Supmeca/Paris School of Mechanical and Manufacturing Engineering (France), Prof. Rezia Maria Molfino from the University of Genova (Italy), Prof. Mark J. Jackson from the Kansas State University (USA), Prof. Yiwei Dong from the Xiamen University (China) and Prof. Ahm Shamsuzzoha from the University of Vaasa (Finland). The conference program is divided into 4 parts: opening ceremony, keynote speech, oral presentation and poster presentation. Professor E. Bayraktar, as the host of the conference will lead the opening ceremony. Then, Professor Seeram Ramakrishna, the top 1% Highly Cited Researchers in materials science and cross-field categories, delivers his keynote speech with the title of "Reimagine Materials to Deal with the Existential Threats to the Humanity", lasting for 35 minutes. Then, professor Qiang Xu from the University of Huddersfield, UK, gives his keynote presentation with title "Modelling of Creep Rupture". 24 oral presentations are arranged in turn and each one lasts for 15 minutes with Q&A followed. And 36 poster presentations are displayed.

This year, MMSE has attracted 165 papers, 78 are accepted by our reviewers and editors after the peer review process, covering topics from mechanical engineering to mechatronics systems, material science, automation and control engineering, applied physics and engineering technologies.

Sincerest appreciation goes to the conference chairs, all members of conference committees, the keynote speakers, as well as all the participants for their support to MMSE. Many thanks go to the publisher-IOP Publishing for their work and support on publishing the proceedings. Finally, I sincerely hope that MMSE 2021 will be a forum for excellent discussions that will put forward new ideas and promote collaborative research in the future.

List of Conference Chairs, Co-Chairs, Publication Editors, International Committee Members, are available in this pdf.

All papers published in this volume of Journal of Physics: Conference Series (JPCS) have been peer reviewed through processes administered by the Editorial Office. Reviews were conducted by expert referees to the professional and scientific standards expected of a proceedings journal published by IOP Publishing

• Type of peer review: Single-blind / Double-blind / Triple-blind / Open / Other Double-blind

• Describe criteria used by Reviewers when accepting/declining papers. Was there the opportunity to resubmit articles after revisions?

a) The first checking includes the insufficient originality, serious scientific or technical flaws, out of conference topics and so on. Particularly high rate of similarity or lack of a significant message will be rejected directly at this stage.

b) Then, submissions will be peer reviewed by 2-3 independent reviewers who have published 5 or more research articles in recent 3-5 years in this field. Each submission will be reviewed follow its relevance, originality, technical quality, significance of the submission; there will be four results within 2-3 weeks: Accept/Reject outright/Consider after Major/Minor Revisions.

c) Authors have 2-3 weeks to resubmit an updated version of their submissions with the necessary changes for further evaluation, which should follow the comments and suggestions from our reviewers. Only those submissions passed the peer review and accepted by the reviewers and editors will be included in the conference proceedings finally.

• Organizer

China University of Geosciences(Wuhan), China

Supmeca/Paris School of Mechanical and Manufacturing Engineering, France

• Conference submission management system: Online Conference Email: mmse2021@163.com (Miss Xu)

• Number of submissions received: 165 Submissions

• Number of submissions sent for reviewing: 136 Submissions

• Number of submissions accepted: 78 Submissions Accepted

• Acceptance Rate (Number of Submissions Accepted / Number of Submissions Received X 100): 47%

• Average number of reviews per paper: 2-3 Reviewers

• Total number of reviewers involved: 56 Reviewers

• Any additional info on review process (ie plagiarism check system): Plagiarism check system: iThenticate

• Contact person for queries:

Name: Fannie Xu,

Affiliation: China University of Geoscience (Wuhan), China

Email: mmse2021@163.com

A two-dimensional finite element model is used to explore the fracture parameter in the tip region of stress corrosion crack (SCC) of AA6082 alloy. Based on the ABAQUS code, we investigate the effect of oxide film's yield stress on the Mises stress and equivalent plastic strain (PEEQ) in the crack tip. The results show that as the yield strength of oxide film increases, the Mises stress and PEEQ of base alloy in crack tip area both decrease, and the stress of oxide film in crack tip also reduces, but the strain increases. This is because the oxide film bears more load, so the load on the base alloy of the crack tip becomes smaller, resulting in a reduction in the stress and strain on the base.

Influences of annealing temperature on microstructure, electrical properties, stability, and film adhesion of Pt thin film resistors with Ti interlayer and Pt_xO_y interlayer were investigated and compared. Pt thin films were deposited on Al₂O₃ substrates with Ti interlayer and Pt_xO_y interlayer, respectively. Two resistors showed different microstructures after annealing. Pt/Pt_xO_y film resistor owed more stable resistance value and larger temperature coefficient of resistance (TCR) than those of Pt/Ti film resistor. Annealed Pt/Ti film resistor exhibited poor stability than Pt/Pt_xO_y film resistor and the stability became worse with increasing annealing temperature. In addition, the film adhesion of two resistors was discussed.

CoNiCrAl alloys are widely employed as a high temperature resistant material in thermal barrier coating (TBC) systems. In such materials, the adherence between the thermally grown oxide (TGO) Al₂O₃ scale and the alloy is strengthened by oxide pegs formed by dispersed oxide addition or the oxidation of doped reactive elements. In this study the addition of Ti as the reactive element to a CoNiCrAlY alloy has been addressed. We investigated the mutual effects between Ti and the oxide pegs in alloy samples that had been subjected to a cyclic oxidation process. The alloy with a higher Ti content exhibited a uniformly fine β-phase and fewer voids at the scale/alloy interface, the scale growth rate was lower for Ti-containing alloys. In addition, the formation and growth of oxide pegs led to an irregular distribution of Ti in the scale and at the scale/alloy interface, which resulted in local variations in the features of the scale, with fewer voids and a thinner scale at the sites that are far from the oxide pegs. Meanwhile, the incorporation of Ti to the Y-rich oxide led to an increase in the bonding strength between the peg core and the Al₂O₃ sheath.

The existing emulsified asphalt has the defect of adhesion to construction vehicle tires, which leads to the failure of interlayer adhesion. From the softening point of improving the evaporation residue of emulsified asphalt, Non-sticky wheel emulsified asphalt was prepared with different matrix asphalt, modifier and modifier dose. Combined with the standard viscosity, storage stability and evaporation residue of emulsified asphalt, the technical properties of Non-sticky wheel emulsified asphalt were analyzed. The viscosity wheel performance of Non-sticky wheel emulsified asphalt was tested by viscosity wheel performance test. Compared with ordinary emulsified asphalt and SBR modified emulsified asphalt sold in the market, its non-stick wheel effect is significant under the condition of 60°C, which has good engineering practical application value.

The compatibility of styrene-butadiene-styrene (SBS) with base asphalt is known to restrict the application of SBS modified asphalt. In this study, carbon nanotubes (CNT) were used to enhance the compatibility between SBS and base asphalt. The effect of CNTs on the compatibility of SBS modified asphalt was investigated by dynamic mechanics analysis (DMA), and the micro-mechanism of CNTs enhancing the compatibility of SBS modified asphalt was studied by using dissipative particle dynamics (DPD) simulation. The results show that CNTs can significantly improve the compatibility between SBS and base asphalt, and the microscopic mechanism is that CNTs can change the distribution morphology of SBS in base asphalt, making the distribution of SBS modified asphalt more uniform, which promotes the development of polymer-rich phase in SBS modified asphalt. This study can provide theoretical guidance for the practical application of SBS modified asphalt.

Compressed natural gas (CNG) has been widely used as an automotive fuel in china, which the service security of CNG storage well (CSW), the main storage equipment in Chinese filling station, is becoming more and more prominent. In order to analyze the stress of CSW and its influencing factors, the mechanical model of CSW + cement sheath + stratum (CCS) processed by both elastic mechanics and finite element method was studied in this work. Using the most common well of Φ177.8× 10.36mm as a calculation case to obtain the analytic solutions and numerical solutions of CCS. The results indicated that the analytic solutions and numerical solutions are very close with relative deviation less than 3%, which verified their reliability each other. The calculation case can prove that the stress of CSW reduced evidently due to the effect of well cementation, which equivalent to the value of circular and axial stress of CSW strengthens to 18% and 20%. And when increasing the elastic modulus of cement sheath, the stress of CSW decreased that the support and potentiation to CSW by cement sheath becomes stronger.

Measurement of a reaction between deuterium (hydrogen) gas and materials using a calorimeter which is calibrated by nitrogen will show erroneous excess heat power production due to the structure of the reaction chamber and the difference of thermal conductivity of the gases used in the calibration and triggering experiments, which leads to the energy generated in the chamber of the calorimeter has not been totally measured. The error is not obvious at low applied power, and it increases significantly with the increase of applied power. This insidious error is discussed by using a stable heat-flow (Seebeck) calorimeter and procedures to reduce error are put forward. And the authenticity of Rossi's patent is questioned.

In this study, advanced low melting point alloys (LMPA)/polymer composited wires for fused deposition modelling (FDM) processes were developed. The Polylactic Acid (PLA) powder was mixed with LMPA powder and multi walled carbon nanotubes (MWCNTS). The liquid state of LMPA will not hinder the processability of polymer composites when the composites were extruded out as wires. Thus, the composited wires can be optimally fabricated with high stabilities as well as large quantities. The prepared PLA/LMPA/MWCNTS wires could be further dedicated to print with 3-dimensional (3D) structures. Additionally, the tensile modulus of the printed composites was three times as higher as that of the pure PLA. The tensile modulus of composites is temperature-dependant, specially it would decrease more significantly at the melting point of LMPA. The study on the FDM of the advanced composited-wires would inspire a new branch in the additive manufacturing. The material could also be potentially applied in variable stiffness components, electromagnetic shielding and other applications.

In this study, an 8mm thick AH36 steel plate was welded using laser + MAG hybrid welding technology. The results show that when the laser power is low, the droplet transition form is droplet transition, the droplet size is larger, and the transition frequency is low. As the laser power increases, the form of droplet transition is jet transition, the droplet size is small, and the transition frequency is high. When the laser power is low, the undercut phenomenon of the weld is serious. With the increase of the laser power, the undercut phenomenon of the weld is improved. Besides, the weld width and welding seam reinforcement will also increase. Laser-arc hybrid welding has a certain gap adaptability. When the laser power is 10KW, the weld profile of 0mm welding gap and 1mm welding gap are basically the same. Properly reducing the laser power is conducive to the larger welding assembly gap of laser arc hybrid welding.

Scanning electron microscopy (SEM) plays a very important role in the process of microstructure, fracture analysis, qualitative and quantitative analysis of micro-area composition, microstructure analysis and so on. With the rapid development of material science and technology, various industries also put forward higher and higher requirements on the technical level of testing. Based on the development background of Scanning Electron Microscopy (SEM), this paper introduces the application of scanning electron microscope in the observation of metal microstructure. Mainly about the characteristics of scanning electron microscope to continuous zooming, equipped with advantages of backscatter diffractometer, large depth of field, is advantageous to the samples from the macroscopic characteristics by combining with the analysis of microstructure, and quantitative analysis to test samples, also can research the fracture morphology of the sample, the recrystallization organization, grain orientation and texture characteristics, etc.

Flexible sensors modified with microstructures possess excellent high sensitivity and ultralow detection limit. In this study, silver-coated-glass fiber-filled silicon rubbers with their net structures were 3D printed and designed. Porous structures were introduced through the multi-layer printing of the net structure. The high conductivity of the printed composites originated from the conductive fillers, which assure the composites applied in circuit connection. Flexible capacitive sensors were further fabricated with the porous composites as electrode layers and the flat polyethylene terephthalate film as the middle dielectric layer. The prepared capacitive sensors owned an excellent sensing property to detect ultralow load with a sensitivity of 0.0666 kPa⁻¹. The evolution of the porous structure was schematically described, when the capacitive sensors were compressed. The net-structured porous capacitive sensors fabricated with 3D process would inspire us a new branch in the printing electronics.

Cu-based composites are widely used in mechanical, electrical, communication, transportation and microelectronics industries due to their excellent properties. However, the difficult match between strength and conductivity is the main problem for Cu-based composites. And thermal-mechanical treatment technologies reached the limit to improve and control their comprehensive performance. Graphene is a two-dimensional layered material with carbon atoms hybridized by SP₂ orbital, and has high strength, good electrical conductivity and thermal conductivity. It is expected to solve the contradiction between the strength and conductivity of the composites by introducing graphene into Cu-based composites. In this paper, the commonly used methods for effective dispersion of graphene and interface bonding were introduced, the researches on the strength, toughness, electrical conductivity and thermal conductivity were outlined, lastly the future development of graphene Cu-based composites was prospected.

Marine fouling is one of the causes of Marine corrosion, which causes material corrosion to sailing vessels and a variety of Marine structures, but also has a great increase on the daily maintenance cost and energy consumption. In this paper, the formation process, mechanism and harm of biological fouling are briefly introduced, and then the application research progress of nanomaterials in preventing Marine biological fouling of ships in recent years is comprehensively discussed. We found that the research mainly focused on the application of nano-oxide materials in Marine biological fouling prevention, and adding anti-fouling agents of nano or modified nanomaterials in the preparation of materials to enhance the properties of materials, which could provide support for further exploration of nanomaterials in biological fouling.

The Sherwood-Frost constitutive model is widely used to predict the mechanical behavior of polymer materials, and it is a very important material model. In this study, the stress-strain curve of high-density polyethylene (HDPE) with a strain rate ranging from 935 to 5450 s⁻¹ was obtained through the split Hopkinson bar test device. Based on the HDPE dynamic mechanical performance test, the method for determining the strain-rate parameters of the Sherwood-Frost constitutive model was analysed and the strain-rate term in the constitutive model revised. Using the experimental results of Sherwood and Frost, the method to determine the parameters of the density and temperature terms in the model was introduced. This study provides a reference for parameter determination and model modification of the Sherwood-Frost constitutive model.

The metallographic study of thermal spraying coatings was carried out on three double coating samples. 'ASTM E3 metallographic Sample Preparation Method' was selected for sample preparation, and coating inspection was conducted according to'HB 20195-2014 Metallographic Examination of Thermal Spraying Coatings'. The interface state, cracks and microstructure of the coating analyzed by' HB 20195-2014 Thermal Spraying Coating Metallographic Examination'. In combination with Image-Pro Plus quantitative analysis of porosity and unfused particles of coating, the thickness of coating was measured by using pull method. For the first coating, the microstructure, crack, coating thickness and porosity were tested. For the second coating, the microstructure, interface state, cracks, coating thickness, porosity and unfused particles were tested. Through the research on metallographic examination of thermal spraying coating, its hoped to provide some reference value for the examination of other coatings.

On-line monitoring of welding quality is very important to the realization of intelligent welding technology and has become a research hotspot in the field of welding technology. This article reviews the research results and latest research progress of welding quality on-line monitoring based on molten pool visual sensing in recent years. First, it introduces the characterization of welding quality by the two-dimensional geometric features and three-dimensional topographic features of the molten pool in detail, and then analyzes the application of machine learning and feature engineering in the online prediction of welding status; we discuss the deep neural network and welding quality at the end Convergence of online detection technology. The work done in this paper reviews the progress of online monitoring technology for welding quality and provides a basis for the follow-up work.

In order to enhance the surface quality and avoid the cracking problem of the wear-resistant layer on guide slippers of coal cutting machines, an automatic welding system was employed for the overlaying welding production. By regulating the welding parameters, including the welding path and speed, the surface flatness and quality were greatly reduced. The cracks at the arc extinguishing positions were effectively eliminated. As compared to the conventional manual welding, the automatic welding not only reduced the machining allowance, but also increased the production rate and the service life of the guide slippers.

As a continuation of the previous research, influences of human vehicle dynamics coupling (HVDC) on miniature electric vehicle (MEV) roll stability are studied by varying driver weight, wheel base and track width. A multi-body dynamics model is developed for the human-vehicle system by ADAMS/Car software considering driver's dynamics and is validated theoretically. Simulation results show that the MEV roll stability is decreased by the HVDC; the influences become greater with an increase in the proportion of the driver weight to curb weight of the MEV in both time and frequency domain; with the decrease of wheel base, the differences caused by the HVDC exhibit an increasing trend in the maximum value and overshoot; and the differences in the steady stable roll angle and phase lag at 0.6 Hz indicate an increasing tendency with the decrease of track width.

A virtual prototype of the transmission system of a module propellant storehouse is established in ADAMS simulation environment. First, dynamic analysis of the key parts of the transmission system, mainly clutch, is carried out. Then, the 3D model needs to be simulated is established in Solid Works. Finally, combined with the macro commands in ADAMS, the virtual prototype model of the transmission system is established in ADAMS, which can complete the dynamic simulation of the whole loading process. In the simulation process, the parameters are adjusted and optimized to meet the actual situation. The simulation results are analyzed and verified, which can provide some reference basis for the design and selection of driving motor, electromagnetic clutch and other key parts of the transmission system.

In the course of electromagnetic launch, the rail deflection deformation seriously affects the service life and launch accuracy of the orbit. In order to reduce the deflection deformation in the process of orbital launch, based on the principle of electromagnetic emission, simplifying the orbit to Euler-Bernoulli beam, built moving load working conditions of the electromagnetic moving load model, using the electromagnetic launcher bore related structural parameters and material parameters for the rail electromagnetic theory analysis and calculation, the analysis results show that under the condition of the same peak current, rail the biggest position in midpoint deflection deformation; under different peak current, the deflection of the midpoint of the rail increases non-linearly. The deflection of the rail can be effectively reduced by increasing the stiffness of the elastic support. According to the above theoretical analysis results, an electromagnetic launching device was developed. The experimental comparison results show that the deflection deformation is reduced by 42.86% and the critical launch velocity is increased by 6.86% with the increase of support stiffness.

This paper proposed three types of milling cutter, including the normal one, the modified cutter with high damping alloy sleeve, the modified cutter with high damping sleeve and gasket, these three type of cutters are identified with type A, type B and type C respectively. The testing items including cutting force, surface smoothness and fatigue life of above three type of cutter are conducted under different working conditions respectively. The result shows that the milling cutter with high damping alloy behaves better and could improve the related performance dramatically. Specifically, the cutting force of the cutters including type B and C is lower obviously than type A at three different directions, and type C cutter has the lowest cutting force and has the best anti-vibration effects. Additionally, under working condition 1, the surface smoothness of the three type of cutters have the similar behavior. But under working condition 2, the high damping milling cutter has at least 30% improvement. Finally, at the aspect of the fatigue life, the milling cutter with high damping alloy has at least 54.55% better performance than the normal cutter, and the wear of the high damping cutter is at least 38.13% less than normal cutter.

Huge ball mill bearings experience a transient period when they are fed with raw material or their basis is impacted. The behavior of such bearings during the transient period is significant to the safety of the machine. In the present paper, the step load is used to simulate this process. Transient hydrodynamic lubricating models of a multi-pocket pivoted pad hydro-static bearing used in ball mill are established. The hydrodynamic and squeeze effects are take into account, and the models are solved using nonlinear numerical methods. The journal center trajectory, time response of the pad tilting, oil pressure in the pockets, and minimum pad film thickness during the transient period are presented. The oil flow rate evolutions out of the main pockets in all pads are exhibited. The effects of step load on bearing performance are discussed. It was found that the decrease in minimum film thickness can be quite large under the step load impact, which may lead to the damage of the bearing.

The inverse kinematics problem (IKP) is at the center of computer control algorithms for general serial manipulator. The exact number of feasible solutions of the IKP is highly dependent on the manipulator structure as well as the desired end-effector pose, and the existing inverse kinematics methods have difficulties to solve all feasible solutions of a general serial manipulator. In this work, a multiple solutions approach is applied to the IKP. Then, three numerical examples are used to validate the effectiveness of the multiple solutions approach, and the numerical results demonstrate that the multiple solutions approach is effective and practicable. Finally, an infinite solutions example is presented to show that the proposed approach could also provide limited number of numerical solutions in singularity.

Stern bearings are the main supporting part of ship stern shafts. Water-lubricated stern bearings have the advantages of compact structure, easy maintenance, no waste and no pollution, and. Water-lubricated stern bearing materials are generally non-metallic materials, which are easy to produce elastic deformation when working. Based on this, fiber resin matrix composite materials are selected as water-lubricated stern bearing materials, and the Fluid-Structure interaction numerical method is used to research the lubrication performance of water-lubricated stern bearings, which is verified by the test with water-lubricated stern bearing rig. The effect of rotating speed on the performance of water-lubricated stern bearing under different loads is studied in this paper. The results provide technical and theoretical basis for the study of water-lubricated stern bearings.

As a high-performance precision reduction transmission equipment with large transmission ratio, high transmission efficiency, high transmission accuracy, stable transmission and low noise, reducer has been widely used in many fields such as industrial robots. The definition of the reducer is studied, the development history of the reducer is briefly introduced, and the classification and characteristics of the reducer are summarized, including traditional reducer, RV reducer, harmonic planetary reducer and cycloid reducer, A new generation of reducer and influencing factors such as transmission accuracy, transmission efficiency, backlash, torsional stiffness, noise, and assembly. The problem of precision reducer is analyzed, and finally the application and development trend of reducer are studied.

In the cold winter, it is a routine task to deicing on transmission lines in severe cold climate so as to ensure the safety and stable operation of transmission lines. Compared with the traditional contact deicing method for transmission line insulators, the using of laser for transmission line deicing has the advantages of sound deicing effect, no damage to the lines, clean and efficient energy utilization, et al. As the laser energy gradually decays with the increase of distance, this paper proposes a new method to realize laser deicing of short-range transmission line insulator by using UAV equipped with laser. In responds to the dispersion problem of traditional control, this paper fully integrates U AV control and laser control platform, the double have been integrated into one, in the new control platform, the U AV control and laser control can be realized simultaneously, the kinematics model of the laser has been established and its forward and inverse solutions have been solved and analyzed. Finally, simulation experiments verify the validity of the model. Compared with the traditional mode, this deicing mode not only realizes the control integration, but also it is easy to operate. It is especially suitable for the operation in the transmission line field environment, which greatly enhances the robot operation efficiency. At the same time, the simulation of laser head sweeping space and deicing operation motion planning based on the kinematic model show that the system designed in this paper can realize the suspension insulators deicing without blind area. The implementation and promotion of this study has important theoretical significance and practical application value for the practicability of intelligent operation and transmission lines maintenance management.

Contact analyses of heterogeneous materials may find crucial applications in many tribological studies. However, the simulations of such analyses may be difficult to be implemented since the nonlinear behaviors caused by the material heterogeneity and contact may be more complicated. Based on Eshelby's equivalent inclusion method (EIM), an arbitrarily shaped inhomogeneity interacting with a contact load may be evaluated by an equivalent inclusion model with a contact load, where the influences of the boundary surface are taken into account through the method of images. In order to improve the computational efficiency, a two-dimensional fast Fourier transform based algorithms (2D-FFT) with zero padding and wrap-around order are employed to solve the contact problem. To benchmark the present solutions, an elastic half-space containing inhomogeneities under Hertzian-type contact load is considered, and parametric studies are further performed to demonstrate the effects of elastic modulus and depth on the stress field.

Complex structure with circular boundaries is commonly used in engineering practice, and it is essential to conduct a detailed analysis of the interior stress field of the structure. The Michell stress function is a well-known general solution for plane elasticity problems in the polar coordinates, particularly when circular boundaries are involved. This work presents an analytical method with the assistance of the Michell solution, which could be seamlessly combined with Fourier analysis. Using the expansion of Fourier series, problems with arbitrarily distributed loads can be handled via a standard procedure. A complete analytical solution is elaborated for an arbitrarily loaded circular ring, and a classical elastic solution is provided for verification.

Hertz's contact theory is widely used in elastic solid contact problems. In this paper, the applicability of Hertz's contact theory in conformal contact problems was examined. Taking deep groove ball bearing and the outer raceway model as an example, both the FEM analyses and the theoretical studies were conducted. It is found that when the radius coefficient of groove curvature is greater than 0.55, Hertz's theory can be practically applied for conformal contact. Contact problems of rolling bearings are generally solved by Hertz's contact theory without considering inclusions and inhomogeneities in the material. In this paper, inclusions are presented in the contact analyses, and the corresponding elastic field distribution of the contact-inclusion model is investigated by using the finite element method.

An inclusion refers to localized eigenstrains appearing in such processes as thermal expansion and plastic deformation. In view of micromechanics, the existence of inclusions may significantly influence the mechanical properties of the engineering materials. A micromechanical model is proposed to determine the variation of the strain energies in the presence of the near-surface inclusions. The corresponding inclusion problem in a half-space is usually difficult to be solved analytically. In this work, the strain energy is evaluated numerically via the method of images, which superposes the counterpart solutions in full-space and eliminates the tractions on the boundary surface of the half-space. The validity of the present work is confirmed by comparing with the published results and the finite element method (FEM).

It is a great challenge to improve the mechanical properties of vascular stent, especially in curved vessels. Vascular stent should have ideal mechanical properties, such as high elasticity, high strength and biocompatibility. At present, most of the literatures focus on the mechanical properties of the stent after expansion, ignoring that of the stent before the stent is implanted into the human body. After the stent is crimped, it has a great impact on the stress fatigue of the stent. Excessive compression will lead to the weakening strength, which cannot support the blood vessel. Therefore, in this paper, an improved algorithm was proposed to crimp and straighten a curved stent to a smaller diameter to generate the required boundary conditions by finite element analysis (FEA). This method is helpful to study the mechanical properties of the stent after being crimped and treat lesions in highly curved locations.

Developing films with great conformability has become a research hotspot in many fields. The conventional method to enhance conformability is to make the film thinner and more compliant, which usually compromises the strength of the structure. For example, developing functional medical bandages that can perfectly conform to the skin surface during cyclic bending of the joints is still a considerable challenge. In this paper, we propose a novel non-uniform kirigami to make the film achieve the same non-uniform auxetic (negative Poisson's ratio) deformation as the skin around the joint area. By mapping the corresponding unit cells to the target surface, the surface can easily achieve the same deformation as the target skin without any alterations in its thickness or adhesion. As the obtained non-uniform kirigami film structure has the same deformation behavior as the target skin surface, the conformability of the structure can be guaranteed during the entire rotation process of the joints. Moreover, the proposed film is also expected to be used in novel biomaterials, such as smart bandages, skin scaffold, etc.

The issue of cavitation of oil in a pipe is a concerning problem in the design of a high-speed refueling device. This paper established a CFD model for the fluid flow of oil in a refueling pipe based on FLUENT and applied a combined VOF multiphase model and Schnerr-Sauer cavitation model to simulate the cavitation behavior as the oil flows around obstacles in a pipe. The effects of refueling speed, obstacle structure, and pipe diameter on the cavitation were numerically studied using the combined model, and the volume and mass rates of cavitation and their distribution characteristics were obtained. The numerical results show that: the cavitation is strong behind the obstacle, which presents a length of 217 mm, maximum volume rate 53%, and maximum mass rate 0.18% as the refueling speed is 10 m/s; reducing the inlet velocity and increasing the pipe diameter can dramatically weaken the cavitation behavior; adding more obstacles leads the cavitation area reduces first and then keep stable gradually, in which the cavitation phenomenon starts from the first obstacle; placing the obstacles alternatively in the pipe can significantly intensify the cavitation, while the cavitation always starts from the last obstacle.

The computational fluid dynamics software fluent is used to calculate and study the hydrodynamic performance of the rotating screw in the water flow field. First, UG is used to establish different parameter calculation models, and then the slip grid method in the fluent is used to calculate the flow field state, thrust and torque of the simulated screw rod under different blade angles and number of blade turns, calculate through the above data obtain the screw rod's pushing efficiency, and obtain the best structural parameters of the screw rod when the best pushing effect is achieved through the comparison of experimental data.

When the projectiles with different head shapes impact and penetrate the concrete targets, the resistances of the target plates to the projectiles are significantly different, which is manifested by the time history curve of different accelerations, velocities and the penetration depths of the projectiles, resulting in the obvious differences of the penetration ability of the projectiles to the targets with a same compressive strength. In order to determine the influence degree of projectiles with different head shapes on the penetration ability, ANSYS/LS-DYN is adopted. The finite element numerical simulation software is used to simulate and analyze the three kinds of rigid projectiles: oval (including double oval and oval), conical (including double conical and conical) and cone oval. Among them, the projectiles all penetrated C40 concrete cylindrical targets vertically at an initial velocity of 700m/s. The results show that the penetration ability of the optimal oval, conical and cone oval projectile is gradually reduced, and the highest penetration ability is the oval projectile numbered as dan001, whose final penetration depth is 539cm.

Hydraulic testing machine is a kind of testing machine that transfers energy to implement mechanical test by liquid as medium. With the emergency requirement of energy saving and emission reducing, it becomes significant to kick off the infrastructure research to optimize the hydraulic testing machine. At present, some new products always designed with experience is without any improvement. Consider the current situation in testing machine industry, and combined with the desire of design lightweight, some job about optimization and parametric design of product was done from the angle of finite element in this paper. Following content is included: getting a more accurate finite element analysis method about the analysis of the base based on Solidworks, Hypermesh, ANSYS, and optimize model of the base by Optistruct. A more reasonable model of the base with full strength is been got. Puts forward a kind of finite elements analysis for the structure of the hydraulic testing machine. Meanwhile, share shape optimization techniques through which the structure is designed more reasonable.

The anti penetration characteristics of natural rubber and the influence of fragment velocity on penetration energy were studied. Through the experimental study, the ultimate penetration velocity of different diameter fragments penetrating different thickness rubber target is obtained, and the penetration process is analyzed. The damage characteristics of target are explained through different stages of penetration. At the same time, the influence law of different residual velocity on the expansion velocity of rubber fragment cloud behind target is obtained, the energy required for the fragments to penetrate the target and the expansion velocity of the fragments after the target will increase with the increase of the fragments' entry velocity.

In recent years, new metamaterials emerge one after another in various fields with various functions, showing a bright future for the development of metamaterials. Negative Poisson's ratio material is one of the promising materials. It has a wide range of applications in mechanical engineering, acoustics and architecture science. This paper attempts to explore the different deformation mechanisms and possible applications of perforated plate materials with negative Poisson's ratio. Finite element analysis is used to simulate a typical perforated plate structure, which shows negative Poisson's ratio effect and abundant deformation forms in vibration condition. In addition to the existing applications in vehicle buffering and building noise reduction, this paper proposes that the perforated plate can be used as a filter screen for water treatment, as well as the filter screen of air purifier. In addition, it can also be used to cultivate precious herb seedlings. Intersects with the medical field, it can even manufacture the vascular embolization treatment device, which can ensure that the longitudinal does not contract and scratch the blood vessel when the blood vessel is opened. On the basis of this study, we can further study the special properties of metamaterials and solve the specific problems in various applications.

A self-attention-based method termed as Vision Transformer (ViT) is applied to efficiently detect the Surface Defects of Steel Plate. The defect image is divided to N*N patches, each of which corresponds to a word, and the whole image data is used as a sentence or paragraph in NPL. A ViT framework is constructed by a learnable module with sequence length of L and 12 multi-head attention layers. We train the proposed model on the surface defects dataset. The experiment results show empirically that ViT has superior performance compared to alternative approaches.

Shell investment casting of AlSi11 alloy was stimulated in this paper. The shell model of AlSi11 alloy casting was established using UG three-dimensional drawing software, and the solidification process of the inner material of the shell was numerically simulated based on the ProCAST software. The final analysis shows that the entire solidification process is solidified layer by layer, and the filling time of the material inside the shell is 14.70s. After solidification and cooling, the shrinkage volume of the internal defects of the material is 7.80 square centimeters, the average shrinkage rate is 17.90%, and the pore volume is 1.70 square centimeters. Through the simulation and analysis of the solidification process, not only can we find out the shrinkage cavities generated in the solidification process, but also can effectively reduce production costs and improve efficiency.

In order to make up for the shortcomings of traditional robot sorting flexibility and limited operation efficiency, the concept of intelligent robot flexible sorting center is proposed in this paper. We firstly conceive its characteristics, then construct its structure, which consists of a robot with changeable claws, a claw storage, an automatic setback stereoscopic warehousing system, an order goods conveying system, a visual recognition information system. Thus make the intelligent sorting intensive system with more functions enables the robot to adapt to a variety of picking methods, showing higher flexibility, higher order sorting quality, higher equipment utilization rate, relatively stable sorting capacity and great adaptability, its application scope can be continuously expanded to meet the needs of more diversified goods.

In order to analyze the reason why tooth surface finish of the inner gear rings for coal cutters can not meet the standard requirement, a series of experimental studies are carried out on the gear-shaping cutter and the corresponding cutting parameters. It is found that the tooth surface finish can not reach the standard after machining with each cutting parameter by using a M2 high-speed steel cutter. Using a M42 high-speed steel cutter + Balchas coating, the tooth surface finish under each cutting parameter can meet the standard requirement. Combining with the requirements of machining efficiency and tooth surface finish, the matching cutting parameters are proposed. This study has guiding significance for improving the tooth surface finish of the inner gear rings for the coal cutters.

The electric motor is an important part of a mobile power station. Under the complex operating conditions, the stiffness of the rolling bearing exhibits strong time-varying characteristics and non-linear characteristics, which is the one of the main sources for the system non-linearity. Taking the angular contact bearing as the research object, the coupled dynamic model of the bearing-rotor system is established to calculate the time-varying stiffness. The bifurcation law exhibited by the system can be attributed to the excitation of the non-linear bearing force. The numerical calculation method is used to study the motion state bifurcation law and dynamic frequency response characteristics under the rated working condition of the motor. Considering bearing damping, clearance and radial load, the bifurcation and time domain diagrams of different parameters, displacements and rotation speeds in different directions are studied respectively. The results show that when the parameters change, the system will experience chaos, quasi-period and period-doubling motion state; Damping suppresses vibration very clearly, while changes in bearing clearance and radial load significantly cause the system's vibration amplitude to increase, and radial load changes accelerate system vibration. A reasonable bearing is of great significance for motor the design of a mobile power station.

In recent years, China's express business volume has steadily increased, which has greatly increased the operation volume and complexity of sorting operations. However, the current logistics sorting process is still in manual or semi-automatic sorting, and the technology in the process of express sorting cannot match the surging order volume in the express industry. And with the rapid development of e-commerce and the increasing personalized demand, customer orders gradually tend to be multi-variety, small batch, multi-frequency, and then put forward higher requirements for the flexibility of the sorting system. In this paper, aiming at the low sorting efficiency caused by the inconsistent standards of goods in the sorting process, based on the idea of automatic tool changing in machining center, a hand changing grasping robot is designed, which includes the structure of cluster, "claw library" and robot automatic claw changing structure. The design can realize the multi-purpose of one machine and improve the flexibility of the sorting system.

Vibration characteristics of packeted bladed disk is complicated. To study the vibration characteristics of the governing stage bladed disk of 660mw steam turbine, cyclic symmetry method is used to calculate the mode shapes. Fourier transformation of vibration distribution in the tangential and axial direction along the circumferential of the bladed disk is applied to obtain the harmonic components. It is found that the Fourier decomposition of each blade displacement contains not only unique component, but also other components. For integrally shrouded blades, the resonance of the m nodal diameter mode can be obtained only when the corresponding natural frequency satisfies the condition ω_n = kn = mn, where n is the rotational speed and m is the harmonic number. For packeted bladed disk, there are additional harmonics that resonance occurs. The harmonic components are related to the nodal diameter number when the number of blades groups and the total number of blades are given. The diagrammatic method is applied to predict the wavenumbers present in modulated eigenfunctions.

Due to the harsh working environment and the inconvenient maintenance, leakages of warship pipeline often occur. When the pipeline leaks, the fluid flow and pressure in the pipeline will change. The pressure fluctuation of the fluid is one of the main sources of abnormal vibration and noise in the pipeline system. In order to locate the leaking part of the pipeline effectively, it is necessary to use sensors to collect and capture these changing parameters to facilitate real-time monitoring of the pipeline system. In this paper, ANSYS finite element analysis software is used to establish the geometric model of "I" type combined pipeline, and the pressure variation characteristics under different leakage conditions are obtained through simulation.

For study the mechanical characteristic of silicone rubber under impact loading, the Uniaxial compression tests of silicone rubber under different strain rates (1 × 10³/s∼6 × 10³/s) and temperatures (233K∼373K) were carried out with test device using the split Hopkinson pressure bar which has a controllers of temperature. The dynamic stress-strain curves and related dynamic mechanical parameters of silicone rubber were generated. The results show that the dynamic compressive strength of silicone rubber at different temperatures has the characteristics of the strain rate strengthening, which increases along with the raise in strain rate. Under dynamic condition, the stress-strain curve at 263K shows the characteristic of transition to "glass state".

The case of fabricating micro-channel on copper foil using micro-scale laser dynamic flexible forming (μLDFF) is investigated in this work. To study the deformation and fracture behaviors, the copper foils are subjected to increasing laser power density until the occurrence of fracture. When laser power density ranges from 0.110 GW/cm² to 0.441 GW/cm², smooth micro-channel features are formed on copper foils, and the depth of the micro-channel gradually increases. Melting marks are observed at the micro-die entrance of the sample with 0.441 GW/cm² laser power density. When laser power density is 0.544 GW/cm², partial fractures are observed. The surface of fracture region is rougher than that of micro-cracks and no micro-cracks regions, which is caused by the higher strain in fracture region. And the fracture edge is irregular, which is caused by the soft effect of material. Complete fracture occurs when laser power density is 0.691 GW/cm².

Utilization factor is one of the most important performance indicators of TBM, which affects the construction period and cost of the tunnel. However, there are few models to evaluate the utilization factor based on geological conditions and operational parameters. In this paper, a novel A-CNN neural network architecture for TBM utilization factor estimation is proposed. Firstly, the input dimension is expanded by a full-connected neural network. Secondly, a convolutional neural network is designed and added behind the expanded input to extract relevant features. Finally, a regressor is designed to build the mapping relationship between the extracted features and the utilization factor. The data collected from a Singapore tunnel project was utilized to verify the proposed method. The results show that the R² of the proposed method on the test set is 0.521, which is 52.33%, 15.60%, 34.10%, and 9.40% higher than the KNN-based, SVR-based, RF-based, and DNN-based methods, respectively. Therefore, the proposed method can estimate the TBM utilization factor more accurately.

With the development of the power industry in China, in order to promote the further efficient and comprehensive development of the power industry in China, it is necessary to achieve precise mechanical automation in power engineering to meet the needs of the power industry in the new era, so that the level of automation of power machinery and equipment demand is higher and higher. Especially in the narrow, special field, mountain construction surface drilling operations of manpower and time cost of the project are heavier, to develop advanced first-class related drilling equipment is necessary, so as to improve the power industry punch into miniature pile operation automation level and efficiency, realize the equipment localization, To meet the requirements of high efficiency in the construction of power engineering, reduce the safety risk of construction personnel, greatly reduce the cost of the project, prevent soil erosion and protect the environment. The control system designed in this paper is to complete the power industry special multi-functional drilling equipment, to achieve the construction of drilling equipment used to drill into miniature piles, mainly through the open CAN bus control, and produced by Jiangxi Dongrui Machinery Co., Ltd., to achieve the control of high real-time and intelligence.

A poly (vinyl chloride) film with triangular pyramid array structure was designed and fabricated. In this paper, a plane to plane hot embossing technique is used to fabricate a triangular pyramid antireflection film on the surface of single crystal silicon solar cells. By testing the optical properties of optical functional textured films, it is found that the reflectivity of triangular pyramid textured films obtained by hot embossing is significantly lower than that of smooth flat films; The absorption and antireflection of high light on the film surface are obvious; The photoelectric conversion efficiency of the solar cell is further improved. Triangular pyramid optical functional structure has great potential in improving the performance of silicon solar cells, which can be applied to different types of solar cells. These improvements are of great significance to the commercialization of silicon solar cell devices.

The purpose of this paper is to explore the causes of universal gravitation, and the law that the gravitation produced by the motion of matter and the absolute dead matter has no mass was put forward. Combined with Newton's law of universal gravitation, Einstein's equation of mass loss, cosmic expansion phenomenon, black hole phenomenon, matter infinitely separable theory and so on, this paper discusses the essence of gravitation. Through universal gravitation, electric field force, magnetic field force and quantum entanglement phenomenon, the concept of wave-point force is put forward, and a theory of gravitation law is obtained, that is, the forces of different wave points do not interfere with each other. Combining dark matter and cosmic expansion, the hypothesis of dark matter gravity law is put forward. Finally, some conclusions are summarized, and this paper puts forward some conjectures.

Operating quantum materials through the application of strong electric field holds great promise for the development of new-generation electronic and photonic technologies with currently inaccessible functionalities. The conventional way of applying gate voltage to produce sufficiently high electric field faces challenge in micro-nano level. Here, we explore polarization field of two-dimensional piezoelectric semiconductors under externally applied strain. The results suggest that the intensity of polarization field can exceed 10 MV/cm near the boundaries of single-layered MoS₂ ribbon. Such polarization field can trigger the metallicity-to-semiconductor (M-S) phase transition of one-dimensional edge states, and even lead to metallic bulk states. Similar phase transition can also be driven by a pure external electric field but the required intensity is in the order of MV/cm. Electric field driving the semiconducting phase of edge states presents the sensitive dependence of ribbon width but relatively robust for polarization field. This study opens a new avenue to manipulate quantum materials by high polarization field.

The fourth-order dispersive nonlinear Schrödinger (FODNLS) equation can simulate the nonlinear propagation and interaction of ultrashort pulses in high-speed optical fiber transmission systems in optics. In this paper, all traveling wave solutions of the envelope are obtained by means of the polynomial complete discriminant system and the elementary integral method. Under specific parameters, the propagation modes of all solutions are given. In this paper, by using the direct integration method, all traveling wave solutions of the envelope of the equation are given, including the singular rational solution, the singular periodic solution, the solitary wave solution and the double periodic solution.

Fluctuation in environmental parameters has become an important factor affecting the performance of ultra precision measurement. Aiming at the long-distance and high-speed laser interferometer measurement system, a method combining structure design and closed-loop control is proposed to reduce the measurement error caused by environmental parameters. The uniform pressure structure is designed, and the control system of micro environmental parameters is established. The simulation and experimental research on the uniformity of temperature and pressure on the optical path measured by laser interferometer are carried out. The simulation and experimental results show that this method can achieve temperature uniformity and stability above 0.01°C and pressure uniformity and stability above 1Pa, and can be widely used in micro environment parameter control of long-distance ultra precision measurement.

Thermal emissivity is one of the most important indices used to evaluate thermal emission capability of an object and is essential for characterization of thermal emitters, especially in the field of infrared thermal emission engineering for various applications, including personal thermal management, radiative cooling and heat preservation, infrared stealth, and infrared encryption. However, due to the natural background thermal emissions from the ambient environment and experimental setup, conventional methods generally ignore the background emissions while keeping the temperature of the radiating sample significantly higher than the ambient temperature. Here, we introduce a simple method that enables accurate measurement of emissivity of a given sample without necessitating high temperature through elimination of background emission noise by the difference of the measured emission signals of the sample at two different temperatures.

Vanadium oxide (VO₂) finds a wide range of applications owing to its excellent reversible phase change properties. We demonstrate a method for doping a polymer with VO₂ nanoparticles towards realizing a thermal emissivity modulation device, which is expected to supplement the conventional preparation of VO₂ film layers using magnetron sputtering, vapor deposition, and such techniques which are relatively cumbersome and expensive. The comparison of thermal emissivity modulation ability of VO₂ film membrane structure on silicon substrate obtained by magnetron sputtering and pressed tablet sample obtained from VO₂ nanoparticles reveals that the latter also demonstrates substantial thermal emissivity modulation ability. Furthermore, the emissivity of this fabricated PDMS-VO₂ blended sample can change from 0.90 to 0.71 in a heating test. This provides us a new technique to fabricate a scalable, cost effective, and widely applicable thermal emissivity modulation device.

During long-pulse plasma operation with high power in tokamak, excessive heat load on divertor may lead to material melting or erosion of the first wall material, which enhances impurity radiation and degrades plasma performance. As an important component of the first wall, divertor cooling system is important for the high power and stable operation of the device. The Experimental Advanced Superconducting Tokamak (EAST) is committed to achieving more than 400 s long-pulse H-mode operations, which is equipped with a first wall of full metal. The 10 MW/m² heat load on divertor means a big challenge for the continuous operation of the system, but the current divertor cannot meet the conditions, so it needs to be upgraded. In order to check whether the cooling water system of the new divertor in EAST can meet the requirements, a fluid test was built to measure the flow rate and flow drop of the divertor. The results show that the difference between the test results and the results of ANSYS-based simulation is 9 %, and the maximum difference between the results of the comparison of two different model parts is 3 %. It is concluded that the cooling water system of the divertor in EAST can achieve the heat load and safety requirements.

With the development of TWT in terahertz band, the size of TWT is greatly reduced and the power gain is also reduced. In order to improve the performance of traveling wave tube (TWT), an E-plane and H-plane tapered folded waveguide slow wave structure operating at 0.34THz is designed. In order to reduce the RF loss, a gradual ridge is added to the E-plane ridge. Compared with other ridge loaded structures, the coupling impedance of this structure has been significantly improved, and it has better dispersion characteristics and higher maximum output power. According to the electromagnetic simulation results, under the condition of 16.8kV, 50mA banded electron beam, the maximum output power of the folded waveguide can reach 65.1w, the power gain can reach 31.8db, the 3dB working bandwidth can reach 12GHz, and the electronic efficiency can reach 7.75%. Finally, a complete DRIE process for processing slow wave structure is explored. The slow wave structure is fabricated by combining silicon with non-silicon.

We consider the optimal setting of n stations and solve the problem of n = 6 in the plane. Let S ⸦ E² be a set consisting of n points A₁, A₂, ..., A_n, d(A_i, A_j) stands for the distance between A_i and A_j, and $\sigma (S)=\sum _{1\le i\lt j\le n}d({A}_{i},{A}_{j})$, $d(S)=\mathop{min}\limits_{1\le i\ne j\le n}\{d({A}_{i},{A}_{j})\}\,,\,\mu (2,n)=\frac{\sigma (S)}{d(S)}\,(S\subset P,|S|=n)$, inf $\mu (2,n)=min\{\frac{\sigma (S)}{d(S)}|S\subset P,|S| =n\}$. In the paper, the results for $\text{inf}\text{\,\,{0.17em}}\mu (2,6)=13+4\sqrt{3}$ are obtained by several analytical methods, such as classifying, regional control and evaluating the boundary extremum.

Nuclear fusion is now the ultimate need for energy, tokamak is one of the possible devices for controlled nuclear fusion. Based on the advanced tokamak magnetic confinement configuration and the research results of fusion physics in recent decades at home and abroad, Chinese Fusion Engineering Test Reactor (CFETR) will carry out innovative physical design to achieve the international requirements. Divertor is an essential component of the magnetic confinement fusion device, which directly sustains the strong particle flow and high heat load. The cooling system of divertor will directly affect whether divertor can function properly. In this paper, a new structure of divertor suitable for CFETR is designed and simulated, both the flow field analysis and the heat transfer analysis of the model were verified. The results show that the designed divertor structure can meet the system requirements.

All staffs are strictly requested to wear hard-hats when working in substations. Various object detection algorithms, especially those based on deep learning, thus have been proposed for the corresponding purpose. A deep learning based-object detection algorithm commonly involves a fundamental neural network which dominates detection performances, so this paper investigates different types of networks' applicability when utilizing them with a typical object detection algorithm for the monitoring of hard-hat wearing in substations. This is conducted from various perspectives concerned by real-world implementation that includes time consumption, computation speed, precision and more. As a consequence, this study provides a guideline to the selection of the most appropriate deep neural network architectures for the specific monitoring scenario.

In this paper, a face recognition system has been designed using Raspberry Pi based on convolution neural network technology. Convolution neural network that using OpenCV (open source computer vision library) to realize real-time face recognition and feature extraction. The difficult and important problem in deep learning network is that it could be over fitting very easily. In order to alleviate the over fitting phenomenon and improve the accuracy of face recognition, the dropout technology of convolutional neural network had been employed to improve the recognition accuracy and ensure the robustness of face recognition. The results of experiments show that our methods has the advantages in the computer time and recognition rate for the low construction cost, simple structure and strong portability. The accuracy of face detection for static and dynamic images using Raspberry Pi is above 85% in our testament.

The normal operation of pipelines will be affected by the surrounding environment. As an outstanding problem, pit excavation with protection on adjacent pipelines has been paid more and more attention in urban infrastructure. Adding retaining structure in soft clay area can effectively reduce the influence of pit excavation on buried pipeline. In this paper, a3D simulation model of pipeline-soil-wall coupling is established. And the effect parameters of soil, pipeline and envelope on pipeline stress distribution, axial strain and pipeline displacement are analysed. It is found that the stress of pipeline concentrated on the middle part of the pipeline after excavation with retaining foundation pit. The larger the elastic modulus and cohesive force of soil, the smaller the deformation of pipeline, while the change of Poisson's ratio is opposite. With the increase of pipeline wall thickness and distance between pipeline and diaphragm wall, the Poisson's ratio is decreased. The internal pressure of the pipeline has hardly affected by the deformation of pipeline, but the deformation of pipeline is increased with the increase of the depth of the foundation pit. The thickness and modulus of elasticity of diaphragm wall have the same change. They are greater with the smaller of deformation capacity of pipeline. These results provide theoretical guidance for the research of foundation pit and pipeline, and provide reference basis for engineering construction.

In this paper, the X-ray computed tomography method was applied to measure the matric suctions of the glass-sheet samples. With the contributions of Cs₂SO₄ solution, the distributions of water among glass sheets were distinctly observed. The shape of the liquid bridges between the glass sheets are not simple circular ring, but rings with the triangular or quadrangular projective planes. Cs₂SO₄ resulted in the coefficient surface tension of the solution decreasing, which is the main reason that the tested values of matric suction were slightly higher than calculated. Overall, the differences between tested and calculated values are less than 3%, which testified that X-ray computed tomography method for measuring matric suction is feasible. The significance of this work is X-ray computed tomography method could be applied in unsaturated clay soil constituted by sheet particles.

In order to investigate the influence of longitudinal cracks on the bearing capacity of wood beams, the simulation models of cantilever beam and simply supported beam with cracks were established based on the FEM and XFEM. Through the simulation, influence of the cracks on stress distribution and bearing capacity of the beams are discussed. Simulation results show that longitudinal crack has an effect of homogenizing the stress field in the wood beam, which is helpful to improve the overall displacement bearing capacity of the beam. Considering that survival with injuries is the normal state of wooden structures, the damage tolerance theory of wood structure can be developed. Therefore, this paper is a preliminary attempt in this field. However, the more complex microstructure of wood will make the damage process more complex. In the future, it is necessary to carry out targeted research, which can not only establish the damage tolerance theory for wood components, but also inspire more in-depth thinking and research in bionics.

In order to quantitatively analyze the action mechanism of the pier flow field on the adjacent bow, Fluent was used to simulate the flow field variation characteristics of a single cylinder pier without ship passing. Secondly, the DES model and the dynamic grid technology are used to simulate the turbulence and the change of the ship's bow moment when the ship passes through a single cylinder pier under different transverse distance parameters. The numerical simulation results under multiple working conditions show that when the ship approaches the pier, the bow moment is significantly affected by the flow field of the pier. With the increase of the distance between the pier and the ship, the influence of the pier flow field on the ship's bow moment is gradually strengthened to gradually weakened.

Abstracts. In this paper, ViT deep neural network based on self-attention mechanism is used in classification for images of soybean and weeds. Firstly, the overall image is split into multiple tiles; with each tile regarded as a word, the whole image is regarded as a sentence, which can be used for image semantic recognition by natural language processing technology. We designed a ViT network with sequence length of 50, embedded dimension of 384, and self-attention module layers of 12. With soybean weed classification dataset, the network is trained, verified and tested. Experimental results showed that ViT network is superior in classification on dataset of soybean and weeds, with excellent generalization capability.

The cross-cut is an important gateway to connect the main roadway and the coal seam. The transportation, the pedestrian and the ventilation of mine could be seriously influenced by floor heave of cross-cut. Aiming at the severe floor heave of +1100 m track cross-cut in Liu Yuan Zi Coal Mine, the cross-cut surrounded with hard roof and soft floor was found. To solve this problem, the bolt-net-shotcrete and 36U-shape steel combined supporting (the original supporting scheme) and the bolt-net-shotcrete and 36U-shape steel round shed combined supporting (the new supporting scheme) respectively were applied to the cross-cut by numerical analysis. The simulation results indicate that the floor heaves is reduced by 57%, and the surrounding rock stress was changed from tension to compression at the bottom and the plastic range decreased and trended to homogenization. Field application results indicat that the cross-cut floor heave can be controlled effectively by bolt-net-shotcrete and 36U-shape steel round shed combined supporting. The conclusions provide a reliable technical scheme for hard roof and soft floor roadway.

In traffic scene, a low detection rate of dynamic target is caused by interference features of background area and fast speed of detected moving target. In this paper, an optimal target detection and prediction algorithm is proposed. Firstly, the algorithm of real-time motion parameters (speed, direction, etc.) detection of moving objects (vehicles) based on the depth theory is studied. The original prediction problem is transformed into the problem of automatic updating rate of uncertain parameters and the problem of minimizing the maximum path distance. Secondly, by on-line estimation of the automatic update rate, the proposed trajectory generated is guaranteed to be the minimum length. The allocation strategy minimizes the maximum distance traveled in the collision free. Then, the stability of the estimation error system is guaranteed base on deep learning algorithm. Finally, the simulation shows that the proposed algorithm can be used for moving target detection and path prediction accurately. The performance of the control system is improved.

In this paper, the parameters of Johnson-Holmquist II (JH-2) model of red sandstone are determined. Firstly, some mechanical properties of red sandstone specimens are tested, including quasi-static compression, SHPB dynamic compression test and Brazilian disk splitting test, and the basic mechanical parameters are obtained. Then, according to the theoretical model of JH-2 and other supplementary literature, some material parameters are preliminarily determined. Finally, by comparing the numerical simulation results with the experimental results, satisfactory parameters are obtained, which can effectively and accurately describe the mechanical response of red sandstone at various stages.

In order to study the trajectory deflection of projectile penetrating obliquely into different materials, the Lagrange algorithm of LS-DYNA was used to simulate the three-dimensional model. The impact angle of projectile is 70°, the concrete target and the soil target are penetrated respectively. The state of the target, the strain nephogram and the stress nephogram of the target under the maximum overload are obtained. The curves of penetration depth, penetration velocity, overload and energy are analyzed. The results show that: in oblique penetration, the projectile's trajectory deflects more in the process of entering the concrete target, and then deflects less; the trajectory deflection of the projectile is small in the process of entering the soil target and a certain distance after it, but it becomes larger when it is fast out of the target.

A hybrid fuel cell bus was taken as the research object. Firstly, the structure and characteristics of fuel cell bus power system were introduced, and the power system parameter design was completed according to the vehicle parameters and performance design goals; Secondly, in order to improve the durability of fuel cell and the economy of power system, a three input single output fuzzy energy management control strategy was designed, with the fuel cell power increment selected as the control variable to coordinate control fuel cell power output and change; Finally, the effectiveness of the fuzzy control strategy was verified basing on MATLAB/Simulink platform, the results showed that the fuzzy control strategy can control the SOC of battery reasonably and effectively, while is better than the power-following energy management strategy in terms of power system economy and fuel cell durability.

Most of the existing aerosol cultivation equipments are bulky, simple-structured and poor in functional stability. Based on this, the author developed a set of automatic control high-pressure fine mist cultivation device, designed the PLC automatic control circuit, and simulated and tested the temperature and humidity change curves. The test results verify the simulation model and the overall device runs well, among which the spray atomization process, and the temperature field, humidity field and velocity field under three atomization modes are simulated. Three atomization schemes are analyzed, and in the end the optimal one is selected. In comparison, the side-by-side spray is completely covered; the atomization is more sufficient. The results show that the time when the humidity reaches 90% in the same position is different under different initial humidity conditions. The atomization humidity maintenance time in different environments is approximately the same, and can be maintained for 4 to 5 hours. It can be seen from the comparison of the results that the greater the humidity, the shorter the heat exchange time and the faster the heat exchange.

As a research hotspot in the field of current computer vision, pedestrian detection is widely applied to many fields, such as video surveillance and autonomous driving. However, the accuracy of pedestrian detection under video surveillance is poor, and the miss rate of small target pedestrians is high. In this paper, an improves the YOLOv3 algorithm and a YOLOv3-Multi pedestrian detection model had been proposed. First, referring to the residual structure of DarkNet, the shallow features and deep features had been up-sampled and connected to obtain a multi-scale detection layer. Then, according to different special detection categories, the spatial pyramid pool (SPP) is introduced to strengthen the detection of small targets. The experimental results show that our method improves the average accuracy by 2.54%, 6.43% and 8.99%compared with YOLOv3, SSD and YOLOv2 on the VOC dataset.

With the rapid urbanization and increasing urban impervious areas in China, the construction of the sponge city has gradually turned to the urban ecological space planning. Based on the theory of landscape safety pattern, the construction of sponge city should improve the rainwater management system from multiple scales and enhance the functional of urban landscape space. Firstly, the paper describes the ecological basement elements of the sponge urban landscape safety pattern, as well as the steps and technical methods of sponge urban landscape planning. Secondly, taking Shenfu New City as an example to elaborate the method of sponge urban landscape planning from multiple scales, the landscape ecological planning. The approach is introduced into the theoretical method of sponge city construction, and the feasibility of the study is illustrated by verificationof model, which provides new ideas and methods for sponge urban landscape planning.

In view of the current situation that the remote sensing inversion of suspended sediment is mainly based on low spatial resolution satellite data, sentinel-2 satellite data with resolution of up to 10m is used to retrieve the suspended sediment content in Harbin section of Songhua River. And the inversion model is established based on the measured data and remote sensing data. The results show that the fitting degree of b3/(B2 + B4) in the multi band ratio and the measured suspended sediment concentration is the highest, reaching 0.904. The results show that the average relative error between the inversion value and the measured value is 19.88%, and the root mean square error is 0.039g/l. The results show that the suspended sediment content of Songhua River is lower than that of other six rivers in China, and belongs to the less sand river. The sediment content on both sides of the bank is higher than that of the center of the river. In the wide river, the suspended sediment content is low, and the suspended sediment content is higher in the narrow area.

This paper briefly introduces the background, theory and recent achievements of building carbon sequestration, and introduces in details of the calculation method and the research characteristics, operability and shortcomings of this method. It points out that the model has conceptual visualization, rich connotation and its role in the design of low-carbon urban space, and its influence factors on the layout of low-carbon space are obtained from the determination of coupling building carbon sequestration according to the area of building units and patches. Finally, the current research trends and methods are reviewed and prospected, and it points out that its the whole life cycle and multi-scale and multi-objective influence mechanism can play a guiding role in the spatial layout of low-carbon cities.