Table of contents

MAEM (International Conference on Mechanical Automation and Engineering Materials) is an annually held conference for all researchers at home and abroad since 2022, aiming to provide a good platform for scholars and researchers in the field of mechanical automation, engineering materials and related areas to discuss the latest developments and achievements, work out good solutions, and make contributions.

The Second International Conference on Mechanical Automation and Engineering Materials (MAEM 2023) was held online from August 2 to 3, 2023 for academic exchanges and discussions.

There were over 30 participants from 5 different countries and regions, including China, Russia, Peru and Malaysia, attending MAEM 2023. The conference program was divided into 3 sessions: keynote speeches, oral presentations, and poster presentations. We greatly appreciate Prof. Zhongjun Ding from National Deep Sea Center, China who presided over the conference, and all participants for attending and sharing!

We are honored to invite 4 experts to give impressive keynote speeches: Professor Haibo Liu from Dalian University of Technology, China; Prof. Yajun Liu from South China University of Technology, China; Prof. Li Guo from Hunan University, China and Assoc. Prof. Elammaran Jayamani from the Swinburne University of Technology Sarawak Campus, Malaysia.

Following the keynote speakers, 3 scholars made oral presentations respectively. And 1 poster presentation came after it. Reporters shared their latest research findings and audiences were actively involved in discussions.

We would like to express our gratitude to the reviewers of these manuscripts, who provided their time and expertise to review papers and facilitate the smooth running of MAEM. We are extremely grateful to the organizers, technical program committee, and editors and extend our most sincere thanks to all the authors for their excellent contribution and work and to participants for their active attendance. Our sincere thanks also go to the IOP Publishing editors and managers for their helpful cooperation during the preparation of the proceedings.

On behalf of the Organizing Committee of MAEM 2023.

List of Technical Program Committee is available in this Pdf.

All papers published in this volume have been reviewed through processes administered by the Editors. 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: Double Anonymous

• Conference submission management system: Morressier

• Number of submissions received: 42

• Number of submissions sent for review: 33

• Number of submissions accepted: 16

• Acceptance Rate (Submissions Accepted / Submissions Received × 100): 38 %

• Average number of reviews per paper: 4.57

• Total number of reviewers involved: 151

• Contact person for queries:

Name: Candy

Affiliation: Wuhan Heruirong Culture Spreads Co., Ltd.

Email: info@icmaem.org

Vibration test is an important method to test the vibration environment during the launch and flight of spacecraft. With the development of China's space industry, large spacecraft weighing more than 10 tons and diameter greater than 3 m are becoming more and more common. Key capabilities such as load bearing, table size, rated thrust and overturning moment of the original vibration test equipment can not meet the needs of large spacecraft development. Therefore, this paper develops a set of 2×350kN dual parallel excitation horizontal vibration test system which can carry out horizontal vibration test of large spacecraft. This paper introduces the structure and design method of the system, and analyzes the test results of the system. The technical indexes of the system all meet the design requirements. The system has been successfully applied to the vibration test simulation of large spacecraft such as the core module of the space station, which provides a better evaluation method for the ground test of large spacecraft in China.

The digital twin is a virtual replica of a physical system that can be used to simulate and analyze its behavior. In fault diagnosis, digital twin technology is used to create a virtual model of an industrial system, and simulate different scenarios to identify the causes of the fault, and predict the system behavior under different conditions. We propose an equipment fault diagnosis method based on digital twin server. Digital twin server is the intermediary between digital model and real device data interaction. Firstly, the principle and function of digital twin and digital twin server are introduced. Then the method of using digital twin server in equipment fault diagnosis is described. Finally, taking the fault diagnosis of underwater propeller as an example, the validity of the fault diagnosis method based on digital twin server is tested. The digital twin fault diagnosis system of underwater propeller connects the digital model and the real sensing equipment, realizes the fusion of virtual and reality, and the accuracy of the resolution of the short-circuit fault between turns of the stator winding of underwater propeller can reach 85%.

A methane telemetry system based on Tunable Diode Laser Absorption Spectroscopy (TDLAS) is proposed for the long-range, high-precision, and real-time measurement of methane concentration in coal mine safety production. The output wavelength of the tunable semiconductor laser is controlled to scan at 1654nm (6045.94cm⁻¹) of the methane absorption spectrum. The harmonic signal is obtained by digital phase locking technique, and the effect of light intensity variation on the system measurement results is eliminated by 2f/1f signal processing technique. Through calibration experiment and measurement error analysis, the measurement error of the system is less than 10%, which proves that the device has the advantages of high accuracy.

Pollution of the environment, especially the marine environment, is currently a rather serious problem. The impact of noise on the fragile biota of the Arctic with an increase in shipping in this region is quite strong. The manufacture of new low-noise devices at an enterprise engaged in the creation of surface and underwater vessels is a very costly process. Computer simulation systems can reduce enterprise costs. The author proposes a system for complex modeling of low-noise devices that could predict the approximate behaviour of a viscous incompressible fluid (gas) in the form of vorticity per single object, described by Navier-Stokes differential equations for the case of fluid motion in a limited space. The system includes: a computer model in the well-established FlowSimulation system and a machine learning model. According to the results of the experimental study, the author found that the model from FlowSimulation has a clearer picture, but for FlowSimulation this is the limit of possibilities, and for the machine learning system there is the possibility of further development to improve the image. In the future, the author intends to continue experiments on training the model in order to obtain a better image.

Forging equipment is equipped with an access platform with a size that significantly differs from that of the equipment body, so modeling methods such as envelopes and sequence pairs cannot be used to accurately describe the equipment or layout. In this paper, we propose a profile layering method for forging equipment, and establish a model of production line layout by setting a layering level using the Cartesian coordinate system, so as to lay a foundation for the subsequent research on interference detection, layout optimization and trajectory planning for production lines.

Safe deployment is the premise of submerged mooring system before it is put into use. In this paper, on the basis of analyzing the deployment process of the full ocean depth submerged mooring system, a calculation model of the laying process is established, and the influence law of the laying movement of the submerged mooring system, under two working conditions of deployment in the deep sea and deployment in the shallow sea, is analyzed and studied. The relevant results have certain guiding significance for the design and engineering application of the submerged mooring system.

Fixtures have an important influence on the machining process of thin-walled parts (TWP) and directly determine their final quality. Aiming at the problem of machining deformation caused by weak rigidity of TWP, an ice-based fixturing (IBF) is designed by taking advantage of the rigidity and viscosity of ice. The feasibility of IBF is then demonstrated based on the published papers of the authors of this paper. Afterwards, the structure and refrigeration process of IBF are described in detail, and the refrigeration capacity of the IBF system is analyzed, and the experimental results show that the IBF can achieve uniform and reliable icing. Finally, the process steps are formulated. This paper can provide a valuable reference for the development of advanced fixtures.

Aiming at the problem of the gradual reduction of the weight and the external wind disturbance affect flight performance of the quadrotor Unmanned Aerial Vehicle (UAV), a dual-loop finite time control strategy based on Radial Basis Function (RBF) neural network is proposed. The UAV model under disturbance is decoupled into position outer loop subsystem and attitude inner loop subsystem. In the outer loop, the changing weight and the external wind disturbance are approximated by using RBF neural network, command filter is used to avoid the "computing explosion" problem in the traditional backstepping method, and the finite-time control method is able to improve the convergence speed of the position. In the inner loop, the cascade RBF neural network PID control which relies on the self-learning of neural network to realize the dynamic tuning of PID parameters is adopted to achieve rapid convergence of the attitude angle. The simulation results show that compared with the traditional backstepping method and cascade PID control, the convergence time is reduced by 31% on average, which verifies the superiority and effectiveness of the proposed control strategy.

This article analyzes a well using 5 "Based on the analysis of the chemical composition of the drill collar, mechanical property testing, metallographic structure analysis, fracture morphology and energy spectrum analysis, as well as the analysis of the stress, bending strength ratio, and double shoulder structure of the drill collar, combined with the deviation of the well section where the drill collar fracture occurred and the drilling pressure during drilling, it is clear that the main reason for the failure of the drill collar is that there is a large well deviation in the area and the drilling pressure is not properly reduced, resulting in The drill collar undergoes severe bending alternating stress and initiates fatigue cracks and propagates at the root of 1-2 threads at the large end of the external thread.

As an environmentally friendly, more efficient and operation-reliable technology, magnetic refrigeration is promised to replace traditional gas compression refrigeration. In our study, we studied the influence on magnetism and magnetocaloric effect of (Gd_xTb_1-x)₃Al₂ (x=0, 0.2, 0.4, 0.6, 0.8, 1) systematically. These results indicated that the increase of Gd concentration increased the lattice constants due to larger atomic radius of Gd atom. Simultaneously, the Curie temperature is dependent on magnetic interaction between Gd atom and Tb atom, and reduced from 279 K to 190 K for x=1 to x=0. Arrott plots indicated that (Gd_xTb_1-x)₃Al₂ compounds showed the characteristics of second-order magnetic phase transition. Under a magnetic field of 0-2 T, the maximum isothermal magnetic entropy (-ΔS_M)^max of (Gd_xTb_1-x)₃Al₂ (x=0, 0.2, 0.4, 0.6, 0.8, 1) compounds are 4.13, 3.79, 3.91, 4.08, 3.96 and 3.98 J/(kg K), respectively. Moreover, refrigeration capacity RC of (Gd_xTb_1-x)₃Al₂ are 59.7, 69.0, 77.6, 65.0, 76.1 and 75.6 J/kg, respective. Adjustable Curie temperature, lower magnetic and thermal hysteresis, (-ΔS_M) and RC suggested that, (Gd_xTb_1-x)₃Al₂ compounds can be used as candidates for magnetic refrigeration.

Titanium alloys are extensively used in aerospace and medical engineering owing to their exceptional mechanical properties and biocompatibility. For a long time, the low thermal conductivity of titanium alloys has made them difficult to machine with conventional approaches. Electrical discharge machining (EDM) is a nonconventional method for machining difficult-to-cut materials. However, it is not possible to achieve high-quality surface finish while simultaneously maintain high machining efficiency. This paper introduced a new EDM approach to obtain high surface quality in machining titanium alloy Ti-6Al-4V with discrete semiconductor electrodes by utilising a new multi-channel discharge principle to disperse the discharge energy. To explore the dissimilarities in discharge characteristics between semiconductor electrodes and traditional copper electrodes, continuous discharge waveforms of both electrodes were compared. Through modelling the discharge equivalent circuit and analysing workpiece surface using scanning electron microscopy (SEM), it was discovered that, due to the unique electrical properties of the semiconductor, it is possible for semiconductor electrodes to form multiple discharge channels. The outcomes reveal that the utilization of semiconductor electrodes can disperse discharge energy and enhance surface quality without sacrificing material removal rate compared to the use of conventional copper electrodes.

In order to allow more reactive material to enter the penetration hole when the initiation delay time of reactive material arrives, a double-layered liner structure with inner and outer liners of unequal height is designed. The outer liner is polytetrafluoroethylene/aluminum (PTFE/AL) reactive material, and the inner liner is metal material. The AUTODYN software were used to study the effects of height ratio α of the inner and outer liners and inner liner material on the reactive composite jet forming and penetrating C35 concrete target. The results show that when α varies, the composite liner forms a reactive composite jet composed of different materials at the head. When α is 4/5, the composite jet can both cause a large penetration depth on the target plate and allow more reactive material to enter the penetration hole. When the material of inner liner is titanium, almost all the reactive material follows the metal precursor penetrator into the penetration hole, which can significantly exert the combined damage effect of penetration and demolition.

Research on polyfurfuryl alcohol (PFA) bioresin has increased due to its unique flame-retardant property. This study utilised the hybridisation of carbon and flax fibres in combination with PFA resin to make fibre-reinforced polymer (FRP) composites. The samples were tested for low-velocity impact at an energy of 20 Joules. Results showed that the fibres-hybridised PFA-based sample had higher energy absorption compared to the carbon-fibre only sample. More importantly, the hybridised sample retained almost the same amount of flexural modulus after impact, while carbon fibre only FRP sample lost more than 20% of its flexural modulus. This highlights the benefits of hybridisation in impact resistance and retention of mechanical properties post-impact in the presence of PFA resin, which is consistent with previous reports of epoxy-based FRP composites. In conclusion, the combination of fibre hybridisation and PFA bioresin presents a promising solution to meet strict flame-retardant requirements, impact resistance needs, and reduce environmental carbon footprint for engineering applications.

An in-situ Dynamic Mechanical Analysis (DMA) method for soft matter developed by our group [Wu. et.al. 2022] encounters the problem of irregular samples, which significantly vary in shape and size in practice, therefore a standard sample "large enough" to ignore the boundary and size effects is necessary to determine the baseline of test and build the correspondence between this new method to classical mechanical tests. In this work, we use finite element analysis to approach the optimal size of a brick sample where the stress on the boundaries in three spatial directions are ignorable, and certified the results by testing a series of silicone gel samples on the in-situ DMA device. The stress-strain of tensile and compression are characterized. The material properties of gel are chosen to be close to the biological soft tissue. The size of 40mm(L)×40mm(W)×20mm(H) is determined to be the optimal result.

To study the dynamic response and deformation evolution of the rectangular recycled aggregate concrete-filled steel tubular (RRACFST) column under small-equivalent loads and weak disturbances, the measuring methods of blasting and the arrangement of measuring points were precisely handled. Three contact explosion tests were conducted on the RRACFST column to obtain their failure modes, dynamic strains, and accelerations. The research results indicate that the range of 20-30g TNT equivalent represents the starting point and critical point of plastic deformation for the RRACFST column. When the explosive quantity increases incrementally under small-equivalent loads and weak disturbances, the radius and size of the explosion crater do not exhibit a linear relationship. The methods of explosive treatment under small-equivalent loads and weak disturbances adhere to the core principles of precision and quantification, meeting engineering requirements. This study provided a theoretical basis and experimental basis for the safety study of RRACFST columns structure under explosion load.

The evolution of ferroelectric/ferroelastic domains in ferroelectric materials (FMs) under stress fields is a significant yet complex process. This process involves the interaction of hierarchical domain structures across scales, as well as the coupling of elastic and electrical potentials. To understand the critical local microstructure evolution, here we used in situ transmission electron microscopy (TEM) to directly observe the hierarchical domain evolution induced by stress in BaTiO₃ and Pb(Mg_1/3Nb_2/3)O₃-PbTiO₃ (PMN-PT) sub-micrometer pillars. The results indicate that domain evolution is sensitive to the loading methods, including loading/unloading speed, stress maintenance duration, and stress amplitude. Assisted by phase-field simulations, we have proved that mobile point defect pinning effect also influence the domain evolution greatly. Based on above understanding, we successfully achieved a large recoverable deformation in PMN-PT pillar with 10% strain. Our findings provide a novel avenue to develop super-flexibility in FMs.