Table of contents

The progresses of understanding of the corrosion inhibitor adsorption on copper surface from extensive experimental studies were reviewed here. In this respect the kinetic and equilibrium studies involve organic compounds, non-organic compounds and their derivatives on copper surface from the solution. Kinetics and equilibrium adsorption of corrosion inhibitors at the copper surface depend on the nature of compounds and the nature of the copper surface. Studies have been reported on the influence of corrosion inhibitors structure, concentration, media as well as temperature that inhibitor was used in on inhibition efficiency. Moreover, inhibition action mechanisms were also studied. Adsorption models of compounds on copper surface are built to predict of possibilities of newly synthesized compounds to act as corrosion inhibitors by combining theory and practical investigations of substances with similar structure.

The yak horn analysis model is created based on the measurement and analysis of the macroscopic structural characteristics of yak horn. Then, the influences of the conical structure on the stress and strain distribution of the yak horn are analyzed using finite element method. The measurement results show that the macroscopic structure along the axial direction of the yak horn has a gradient distribution, and the steepness of the conical structure is about 42. The analysis results show that the steepness of the conical structure of the yak horn affects the distribution of stress and strain. When the yak horn model with the steepness of 42 is subjected to external load, its stress distribution is more uniform, which can effectively improve the strength and toughness of the horn. The above analysis results show that the excellent mechanical properties of yak horn are closely related to its structural gradient, and the steepness of 42 is a long-term natural optimization result, which is benefit to structural bionic design.

Aiming at the credit evaluation problem of commercial banks, this paper proposes a new personal credit evaluation method based on the existing SVDD algorithm--the improved SVDD algorithm, and introduces the theory and derivation of the algorithm in detail, based on this, an example is given.and tested, the results show that the improved SVDD effect is indeed better than SVDD.

Braided wire rope is vital for stringing conductors with tension in overhead transmission lines. Its structure and characteristics determine the safety and reliability of the stringing construction. Tensile loading is the main load-bearing form of the steel wire rope in this process. This study analyzes distributions of stress and deformation in braided wire rope subjected to tensile loading. A geometric model for YS9-8 × 19 braided wire rope was established, and the finite element simulation of the tensile process was carried out using explicit dynamics. The simulation results are analyzed to reveal the distribution laws of stress and deformation on whole rope and intermediate cross section.

In order to explore a new way to improve the static and dynamic performance and lightweight of machine tool, the machine tool worktable filled with basalt fiber polymer concrete (BFPC) is designed, which take a worktable of vertical machining center as the research prototype and meet the stiffness and light weight as the constraint conditions. The static, dynamic performance weight of prototype structural columns are simulated and analyzed by using Workbench software. Taking the width and height of rectangular hole of worktable filled with BFPC as design variable, taking the maximum stress and maximum strain of prototype worktable as constraint conditions, taking maximum of the first three order natural frequency and the lightest mass of worktable filled with BFPC as object function, the sensitivity histogram and response surface of each parameter are acquired by using optimization design. Then the best width and height of rectangular hole of worktable filled with BFPC are finally determined. The static and dynamic performance, quality and the first three order natural frequencies of the optimized filling structure are compared with the prototype structure. Finally we can know that the static, dynamic performance of the machine tool can be improved by using worktable filled with BFPC and ensuring light weight.

The flowability of metal powder is an important factor that can affect the quality of printing metal parts in powder bed, which has a significant effect on the quality of 3D printed parts. In this paper, the commercial TC4 powder prepared by plasma atomization (PA), Electrode Induction-melting inert Gas Atomization (EIGA) and plasma rotation electrode process (RFP) was used as the research object. The traditional static flow test method and FT4 powder rheometer were used to test the dynamic performance of TC4 powder. The flowability properties of powder materials are characterized by the combination of integral properties and Dynamic rheological properties to determine the more important powder flowability parameters for 3D printing and to provide a theoretical reference for the preliminary screening of powder for printing. The results show that the particle size, particle size distribution, particle surface finish and particle size uniformity have great influence on the flowability, but the effect of particle size composition on the apparent density is not a single value. The powder sample with good surface finish and uniform particle size has good flowability. The basic flow energy of the powder sample produced by PA is small, the shear stress between the powder layers is small, and it is easy to slide, but not easy to improve the flowability of powder by aeration. The basic flow energy of powder samples produced by EIGA is the highest. Powder compressibility is the worst. Its air permeability is not good, the wall friction action is small, is not easy to adhere. The effect of vibration on the flowability of powder is small. The basic flow energy of the powder samples produced by RFP is smaller because of its large particle size and better sphericity. The compressibility and permeability of the powder are better. The shear action between the powder layer and the interlayer and the friction on the wall are smaller and the relative viscosity is weaker. The powder is insensitive to the flow rate, and the effect of vibration on the flowability is relatively small.

This paper aimed at the problem that it is impossible to evaluate the depths of the surface-breaking defect of austenitic stainless steel pressure pipes using the Magnetic Particle Testing(MT) and Penetration Testing(PT) methods. A quantitative method for measuring the depths of the surface-breaking defect of austenitic stainless steel pressure pipes based on eddy current array testing (ECAT) was proposed. According to the imaging features of defective ECAT correlation, by analyzing the change trend of the color, impedance amplitude and impedance phase of the C scanning, the corresponding relationship between the depth of the defect can be established, and finally, the effective evaluation of the depth of the opening defect on the surface of the material can be realized. Simulation and experimental results verify the effectiveness and reliability of the proposed method.

The design method of pressure vessel consists of the elastic analysis method and the elastic-plastic analysis method. The design method based on elastic-plastic theory with more complex computation process contributes to lightweight design, and avoids uncertainty of stress classification in the complex structures. Tubesheet is the main part of high pressure heater, which is very thick based on Chinese code GB151 for the design of heat exchangers. Increased tubesheet with large thermal stress are not conducive to manufacture, heat transmission and detection. The application of limit load method and elastic-plastic method in the analysis and design of high pressure heater tube is to provide direction for the lightweight research of tubesheet. It is shown that high stress appears on the inner wall of jointing of tubesheet with the head due to the original tubesheet owning enough rigidity related to thickness, which should be noted in the design. The limit load method and elastoplastic method could be assessed in the plastic collapse assessment after optimizing the thickness of the tube plate by 5% on the basis of the existing rule design. Compared with the limit load method, the elastic-plastic method could obtain higher limit load due to its higher computational precision. On the other hand, the design method of elastic-plastic analysis method is not required to consider the determination of limit load per ASME VIII-2 judged by its convergence. The elastic-plastic analysis method is worth further study, which is helpful to the revision and improvement of relevant standards in China.

Biodegradable materials are of great importance in the development of novel drug delivery system. Here, the apatite/gelatin composite microspheres were synthesized as the mixture of apatite and gelatin was emulsified in the plant oil and then cross-linked with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride and N-hydroxysuccinimide. Their biodegradability and drug delivery property were evaluated. The resultant microspheres were characterized with an optical microscope, a scanning electron microscope, a transmission electron microscope, an X-ray diffractometer and a Fourier transform infrared spectroscope. The results have indicated that the as-synthesized microspheres were spherical in shape and had a size range of 50-230 μm. After soaked in the phosphate buffer saline (pH = 7.4), the composite microspheres were biodegradable and their biodegradation rate approximated 28 ± 2% after 14 days of incubation. It was further found that the present composite microspheres could support the encapsulation of tetracycline hydrochloride as model drug and presented a sustained drug release behavior.

In order to reduce the damage caused by vehicle-bridge collisions and improve the safety of road vehicles, a design method based on stiffness matching was proposed. The vehicle-device-bridge dynamic model was established. The optimal design of the vehicle-collision prevention device for bridges was carried out based on stiffness matching. The collision models were established by using Ls-dyna finite element analysis software, and the protective performance of the collision prevention device for car and truck under typical working conditions were studied. The results show that the stiffness of the anti-collision facility is inversely proportional to the deformation and directly proportional to the impact force. Compared with the impact of bare piers, the peak value of the impact force is obviously reduced after the anti-collision device is added. due to the different rigidity of the vehicle, the maximum peak value of the car is reduced by 40% and the maximum peak value of the truck is reduced by 33.6%. The curve is smooth and the peak arrival time is prolonged, thus achieving a better energy consumption buffering effect. The anti-collision device designed by stiffness matching has strong applicability and can exert better anti-collision and energy consumption effects under different collision conditions.

In this report, polyvinyl alcohol (PVA) fibers with high strength and high Young's modulus were prepared by dry-wet spinning, and they were characterized by FT-IR, XRD, TGA and XQ-1A yarn strength tester. The XRD measurement showed that PVA fiber had a single crystal type. The TGA results indicated the heat resistance of PVA fiber was better than that of PVA. The average tensile strength and Young's modulus of PVA fibers were 1.73 GPa and 40.02 GPa, respectively, their strength were high enough to meet the requirements for the use of civil and architectural.

The paper deals with the fracture analysis of 1Cr17Ni1 after tensile(quasistatic fracture) and impact testing(Dynamic fracture) at room temperature. The temperatures of solution are 900°C, 950°C, 1000°C, 1050°C, 1100°C and 1150°C, respectively. The influence of thermal expositions on tensile properties is found to be obscure. On the other hand, remarkable effects of solution temperatures on room temperature impact toughness are observed. Dynamic and quasistatic fracture behaviour of the 1Cr17Ni1 stainless steel is strongly affected by Volume Fraction, shape of Martensite Islands. In this paper, quasistatic fracture and dynamic fracture behavior of granular structure steels is predicted by Eshelby equivalent inclusion model incorporating the plastic deformation of martensite islands. According to the above laws, we establish the relationship between volume fraction/shape of Martensite Islands and mechanical properties in order to provide technical support for improving the dynamic mechanical properties of the material.

The multi-point thermoforming (MPTF) process of resin sheet are introduced, the material parameters of resin sheet and elastic cushion are got, the finite element model of MPTF for resin sheet is set up, and numerical simulations of cooling shrinkage deformation of resin sheet are carried out. The influence factors such as material, thickness and radius are studied by lots of numerical simulation, and the shape compensation of cooling shrinkage deformation is put forward to deduce the forming error. Then, MPTF experiment of spherical part with Polymethylmethacrylate (PMMA) sheet is put forward, and the comparisons of shape error between experimental parts and object surfaces are obtained. Consequently, it is confirmed that PMMA sheet formed by MPTF after shape compensation has good shape accuracy.

A static stiffness model of the machine tool end considering the whole kinematic chain of the machining system is proposed. The whole kinematic chain is divided into the cutter subsystem and the handle-spindle-motion axes subsystem. The two subsystems are equivalent to a variable diameter cantilever and a variable length cantilever. The 3D static stiffness at the end of the machining system could be resulted by both theoretical calculation and experimental measurement. The static stiffness along different directions are analysed based on the force ellipsoid theory.

The brittle graphite machined surface quality cannot be completely evaluated only by surface roughness Ra measured by profilometer, owing to its 3D surface defects. This paper developed an image detection system for brittle material machined surface quality based on Matlab and VB seamless interface mixed programming. The system hardware setup, software constitution and system programming principle are emphatically elaborated. Finally, the application of this system to detect brittle graphite surface quality proved its good feasibility.

With the rapid development of turbo-machinery, foil bearings became a very important type of high-tech mechanical components. Mechanical structure is one of the key influence factors on the progress of foil bearings. Different structure design characteristics of the bearings were described and compared by reviewing published results and patents. Future developments of the patents and models on foil journal bearings were presented to improve the current design structures. Finally, we know what will be done.

First of all, it defined the concept of Guang-style furniture firstly. Secondly, it analyzed the features of Guang-style furniture from material consumption, techniques and decoration themes. Finally, it put forward some equipment suggestions expected to be helpful to the modern production with the case of the modern guang-style wooden-carving company T using CNC equipment.

This work focuses on mechanical properties of some phases of cement-based materials, portlandite (CH), calcite and clinker. Nano-indentation experiment is done on CSM instrument to verify the values of these cement pastes, Young moduli obtained by the averaged experimental load-depth curve is close to other references. The results show that: 1) the Young's modulus of CH averaged by nano-indentation experiment is 39.88GPa, which is in relative good agreement with the 40.30GPa by Constantinides, 36.00GPa by Acker and 45.95GPa by Laugesen. 2) By nano-indentation experiment, elastic moduli of CH, LD C-S-H, HD C-S-H, limestone filler and clinker are separately within the region of 38.8-50.6 GPa, 17.1-27.6GPa, 30.54-36.50 GPa, 79.8-90.6GPa and 94.26-114.18GPa. The elastic moduli are determined by experiment and the SEM image of these phases are verified, which is used to describe the microstructure and mechanical properties of this typical phases in cement paste.

Nano-indentation experiments are carried out on two cement pastes in order to get mechanical properties of cement pastes. For the comparison of initial cement paste, metakaolin as a valuable admixture for concrete/cement applications is added, considered to increase the reactivity of pozzolans. Statistical analysis on a number of indent points can be traced back to a medium modulus of elasticity. The averaged elastic moduli of typical phases in cement pastes are thus determined. Young's moduli of CH phases is about 44.7GPa by nano-indentation experiment, which are close to the previous simulation values and other references. Besides, Young's moduli of Calcite and clinker averaged by nano-indentation experiment are 86.695GPa and 102.230GPa, which are separately in relative good agreement with simulation values of 84.549GPa by Jia and 85.41-145.56GPa (porosity: 10%) by Arar. A systematic approach is developed to validate and to assess the elastic parameters associated with each phase. The P-h curves of the simulation and experiment are compared to conclude on the feasibility of the methodology.

The surface morphology after machining has fractal characteristics. This paper attempts to establish the relationship between fractal parameters and the relative machinability of ferrous metal materials. Four kinds of common ferrous metals were selected for turning under the same machining parameters and the corresponding surface topography was obtained by OLYMPUS DX110 ultra-depth microscope. Afterwards the fractal parameters were calculated based on the fractal theory and MATLAB. Finally, the relationship between fractal dimension D and relative machinability Kr was analysed. The results indicated that with the increase of fractal dimension D, the relative machinability Kr shows an increasing trend and the mathematical relationship between them was established, which could provide a theoretical basis for improving the machinability of work-piece materials.

This paper gives a comprehensive overview of the application of different nanometer materials in different food packaging. At the same time, the advantages of nanomaterials used in food packaging is further discussed. The toxicity of various nanomaterials to different cell or organelle was also analyzed and summarized

Thirty percent cement is respectively replaced by equal quantity red volcanic ash and gray one which are from Yunnan province . Under the same diffusance, the mortal test block of cement, cement-gray volcanic ash, and cement-red one were produced, respectively. Meanwhile the mortar mechanical properties of volcanic ash admixture and non-admixture were compared. The results show that adding these two kind of volcanic ashes into cement will reduce the strength of cement mortar system to some extent. On the basis of this, the micro-analysis of the three mortal systems is performed. The results indicate the strength decrease of cement mortal system is caused by decrease of hydrated calcium silicate crystal which are produced through hydration reaction, and decrease of crystal space structure due to adding volcanic ash.

The nanocomposites were prepared by adding nano-CaCO₃, nano-TiO₂ and POE in different proportions to the recycled acrylonitrile butadiene styrene (ABS) plastic. Six different types of recycled ABS plastic modified nanocomposites were prepared. Three mechanical properties of the newly prepared materials were tested, including the tensile strength, impact strength, and flexural strength. The microstructures and physicochemical structures of the composites were further studied by means of scanning electron microscopy (SEM), infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and thermogravimetric-differential thermal analysis (TG-DTA). Through the analysis to determine the best dosage range of toughening agent and filler, the performance of the modified recycled ABS plastic was improved. This also makes the recycled ABS plastic more widely used, which provides a certain value of reference for the recycling of recycled ABS. The results show that the nano-CaCO₃, nano-TiO₂ and POE are uniformly dispersed in the ABS matrix, the mechanical properties of the ABS plastic are improved, and the thermal decomposition temperature of the modified plastic is increased. It also reveals that the tensile, impact and bending properties of 6.6 % nano-CaCO₃, nano-TiO₂ composites are improved.

A new forming method using flexible blank holder with multi-point which can restrain wrinkles was discussed. Better forming results were obtained by changing the number of layers of blank holder. The wrinkling phenomenon of sheet metal parts in the course of multi-point forming is studied by finite element numerical simulation. The distribution of stress and strain and sheet thinning of the formed parts in the course of the non blank holder and flexible blank holder were analyzed. It proved that the flexible blank holder with multi-point forming method can effectively restrain the wrinkle of the sheet. In order to verify the feasibility of the new forming method using flexible blank holder with multi-point, series of relevant forming experiments were carried out by multi-point forming equipment.

One of the key tasks of China's lunar exploration phase three project is to collect lunar sample and return to earth under the condition of unmanned state, and to maintain the original state of the lunar sample, and to ensure the accuracy of the ground data analysis. Reliable sealing of lunar samples is key. This paper designs sealing scheme of lunar sample container, through the iteration test comparison and data analysis, seal structure is optimized, applicable sealing materials are determined. The test verification results show that the leakage rate of lunar sample container is better than that of 5 × 10^-9 pa.m³.s^-1, and the sealing performance meet index requirements, which can realize high purity seal of lunar sample and prevent contamination of lunar sample.

Based on the need for rapid welding of intelligent automotive sheet metal parts, a pneumatic clamp was developed for this process. The design of the fixture measuring mechanism, fixture base plate, clamping device and positioning mechanism was elaborated in detail. The simulation of the vulnerable unit in the fixture system proved that the pneumatic fixture has high safety and reliability.

In this work, saponins were extracted from spina gleditsiae by supercritical CO₂ fluid extraction. The effects of extraction pressure, extraction temperature, extraction time, entrainment dosage and entrainment concentration on extraction process were studied. The optimum conditions for extraction were as follows: extraction pressure as 35MPa, extraction temperature as 45°C, extraction time as 2.5h, the ratio of materials/entrainment (g/mL) as 1:3.0, entrainment concentration as 70%. Under these conditions, saponins yield was 0.975%.

In the actual application process, the corn harvester has problems such as high loss rate of fruit and energy waste. This article analyzes the corn picking device, the reason for the high loss rate is found, and a new picking roller is designed. Through the calculation of the force and torque of the picking roller and the chain during the harvesting process of the corn harvester, the power required for the picking device is obtained, and the hydraulic motor model required for the picking device is further obtained. Through design and analysis, we determined the optimum speed of picking roller in corn picking process: 836r/min, picking roll inclination angle: 35°, and picking roll radial size: 75mm. The article determines that the hydraulic motor model is the American white cycloidal motor WS80.

The effects of different heat treatment conditions (T4 solid solution, T6 solid solution + artificial aging) on the stress corrosion cracking behavior of cast AZ91 magnesium alloy were investigated. The results show that the heat treatment can significantly improve the stress corrosion cracking resistance, which will be attributed to the change of microstructure and composition distribution after heat treatment, improve the corrosion resistance of the alloy, and hinder the hydrogen evolution process of the cathode, thus weakening the hydrogen embrittlement effect. The heat treatment stress corrosion fracture is still cleavage fracture, but the plasticity characteristics are significantly increased compared with the as-cast fracture.

Tensile tests were performed on aluminum alloy 2024 (AA 2024) using a Gleeble-1500 thermal-mechanical simulation system at high temperatures of 350, 400 and 450 °C and strain rates of 0.01, 0.1 and 1 s⁻¹. True stress-strain curves of AA 2024 were obtained. Forming limit curves (FLC) of AA 2024 were theoretically predicted based on Marciniak–Kuczynski (M–K) groove theory. In addition, the predicted curves were validated using the Nakazima method, and the effects of temperature on the FLC were analyzed. The results show that the curves predicted based on the M–K theory were in relatively good agreement with the experimental data. The forming limit of the AA 2024 sheet first increased, reached a maximum at 400 °C, and then decreased as its temperature increased.

In order to solve the problem of sealing reliability evaluation of extraterrestrial celestial body sample container, by analyze and compare the current commonly used reliability evaluation methods, the maximum entropy test method with the minimum number of sample size is selected to evaluate its reliability and the evaluation process is introduced in detail. The method to choose the container seal leakage rate as the characteristics of sealing performance, through test and calculation in the critical point to implement reliability evaluation. At the same time, in view of the specialty of the seal leakage rate of numerical its margin value calculation method is proposed. The results show that the maximum entropy test method can be used to evaluate the sealing reliability of extraterrestrial celestial body sample container with only a small number of tests, which is better than 0.9999 (confidence level is 0.90), and the evaluation results is check calculated by means of the reliability evaluation by variables method, the results are consistent and credible.

Using investigation on Cadmium (Cd) in surface and bottom waters in this bay during 1984-1986, this paper analyzed the horizontal distributions, identified the different distribution trends, and provided block diagram model to demonstrate the migration processes of Cd. Results showed that the horizontal distriution trends of Cd in bay waters were determined by the source inputs, the transport paths and the horizontal and vertical water's effects. This indicated that the distribution trends of Cd contents in surface and botom waters would be consistent even if the source strengths were different. There were three different horizontal distribution trends, namely "Yang's horizontal distribution trends". The horizontal migration processes were showing three different status as 1) the settlement of Cd had not been arrived at sea bottom, 2) the settlement of Cd had been arrived at sea bottom, and 3) the accumulation of Cd had been occurred at sea bottom. The path ways and remaining traces of Cd could be defined in according to "Yang's horizontal distribution trends".

Using investigation on Cadmium (Cd) in surfac waters in Jiaozhou Bay during 1984-1988, this paper researched seasonal variations of Cd contents and the variations of the source inputs, identified the source strength ratio and source input ratio, and displayed the changing processes of Cd. Restult showed that the major sources of Cd in Jiaozhou Bay were marine current, river runoff and atmosphere depostion, and the source strengths were 0.12-6.48 µg L⁻¹, 0.12-1.07 µg L⁻¹, 0.04 µg L⁻¹, respectively. The seasonal variations of Cd contents were mainly determined by the seasonal variations of the source inputs. Marine current was the strongest Cd source and source input in Jiaozhou Bay during 1984-1988, yet the source strength and source input of atmosphere deposition could be considered as very slight. The highest value of Cd contents and Cd inputs in this bay was mainly determined by marine current.

In this paper, a new method of air jet-assisted little quantity lubrication (AJLQL) is proposed to obtain a good balance of cooling capacity, lubrication ability and application cost, and workpiece surface finish and tool wear are researched based on milling experiment of aluminium alloy 7050-T7451 on the platform of established AJLQL system. The results show that: (1) AJLQL can decrease workpiece surface roughness effectively, the degree of influence on surface roughness ranges from large to small is feed per tooth(f_z), cutting fluid flowrate(Q), axial cutting depth(a_p), air pressure(P) and spindle speed(n); (2) under the same other process conditions, tool flank wear of dry cutting is bigger than that of AJLQL, and the flank wear becomes less with the increase of cutting fluid flowrate, which shows the excellent lubrication effect of AJLQL.

The rotary separator is an important part of the thermal power generation milling system. The quality of the separation performance directly affects the economics and safety of the milling system. In this paper, the influence of the structural parameters of the rotary separator on the separation performance is studied by the analysis software FLUENT. The structural parameters include the height of the middle cylinder of the impact cone, the taper of the impact cone and the number of the impeller blades. Through the numerical simulation analysis of the rotating separators with different structural parameters, it is concluded that when other structural parameters are fixed, the higher the middle cylinder of the impact cone, the worse the separation effect. The larger the cone taper is, the worse the separation effect is. The more the number of blades, the better the separation effect.

Creep rupture behavior of Grade 91 heat-resistant martensitic steel under multiaxial state of stress was investigated. Creep tests were conducted at 923K with stress ranging from 125 to 200MPa. The notch root radii (r) of doubled circumferentially U-notched specimens is 0.6 mm. The test results show that the creep rupture life of Grade 91 steel decreases with the increasing of applied stress. The creep rupture behavior was investigated based on the scanning electron microscope and optical microscope analysis.

The macroscopic morphology of Al/steel composite plates processed by friction stir welding was investigated through micro-hardness and shear test. The welding speed is in the range of 20-80 mm/min. The tool rotational speed is in the range of 800-1200 r/min. The plunge depth is in the range of 0-0.7 mm. The effects of different friction stir process parameters to the quality of Al/steel composite plate are analyzed.

In this paper, taking the rocket-assisted cartridge as the research object, systematic analyses and studies have been conducted on its ballistics characteristics. The whole ballistics is divided into three stages. Different ballistics models have been determined according to the different characteristics on each stage., the calculating programs of the processing method of the rocket-assisted cartridge have been programmed and the model of the data processing method and the reliability of calculation have been tested and proved by simulation results.

The material quality level of the power grid seriously affects the safe and stable operation of the power grid in the later period. The variety of power grid materials is involved in a large number of suppliers, and the quality supervision of materials is an important task to ensure the reliable supply of materials. The article establishes the material quality supervision model and analyzes it from the perspectives of system mechanism and management strategy, and puts forward a series of measures to continuously improve the quality of power grid materials, which has certain significance for ensuring the quality of power grid materials.

The paper conducts a systematic analysis of the diagnostic method for the aseismic suitability of ocean platform foundation and constructs a theoretically diagnostic model based on the combination of the grey theory and fuzzy synthesis evaluation technique. Firstly, this model uses the grey statistics technology to establish an evaluation matrix. Then the model determines the weights of related indicators via the grey correlation analysis. In the end, the model provides a comprehensive evaluation with the fuzzy method so that all the diagnostic results are more scientific and reasonable. This paper combines with GIS technology and has successfully carried out an evaluation on the aseismic suitability of one ocean platform foundation in Bohai Bay, which verifies the scientific validity and rationality of this model.

Taking the slope of Yunnan Wuyi Expressway as a case study, the typical geologic generalization models of three kinds of slopes were established by means of statistical analysis. The limit equilibrium method, finite element numerical simulation method, and deep displacement curve type analysis are combined to evaluate the slope stability under various working conditions in a comprehensive way. The relationship between the deep displacement characteristic curve and slope stability, and a slope stability criterion is established based on the characteristics of deep displacement curve. This method is a supplement to the current Chinese standards on slope stability evaluation. According to the analysis to typical slope projects in central Yunnan, this evaluation method is simple and feasible, which is suitable to evaluate the stability of various types of highway slopes in central Yunnan in China.

To study dynamic response of the nuclear containment vessel structure under the action of design basis earthquake and evaluate the seismic performance of structure, the elastic time history analysis of nuclear containment vessel structure is performed to determine the most unfavorable displacement and stress distribution. A 3D nuclear containment vessel structure was modelled in FE package tool ABAQUS to perform time analysis. The maximum displacement in X direction occurred at the top of the structure dome under the excitation of three different seismic records; the time at which the top response acceleration peak of the structure does not coincide with the time of the base input seismic wave peak, and it is mainly related to the relation between the period of natural vibration and the period of seismic waves; Under the different seismic waves' excitation of 0.2 g peak acceleration, the tensile stress around the equipment hole and near connection between the bottom plate and the cylinder body is large, while the maximum tensile stress appears around the hole of the device. In the design of nuclear containment vessel structure, the displacement of the top should be controlled and the reinforcement ratio around equipment hole should be increased.

The influence of the temperature and relative humidity on the moisture content of corrugating medium was studied by experiments. The ideal three-dimensional diagram between the moisture content and the temperature and relative humidity was constructed by the GAB model. The prediction equation of the moisture content and the relative elastic modulus was fitted after analyzing the test results by MATLAB software. The results show GAB model can predict the moisture content of corrugating medium in different temperature and humidity conditions, and the fitting equation can describe the relation between the elastic modulus of corrugating medium and the moisture content. The predicted elastic modulus can be used to evaluate the cushioning properties of corrugated sandwich paperboard.

High-water rapid-setting material is a type of cement-based material, which is high water contained, rapid hardening and has early strength. Hydrating and hardening mechanism of this material have been studied by XRD and SEM, the influence of different curing time, gypsum lime content and water-cement ratio on the hydrating and hardening process was explored. The hydration products were measured by XRD. The results show that ettringite is the main product of hydration and hardening. With the increase of curing age, the amount of ettringite increases gradually. The amount of limestone gypsum affects the amount of ettringite. The lower the water-cement ratio is, the more ettringite is formed. SEM analysis shows that hydration reaction will continue with age. The shape of ettringite turns from the acicular to the columnar. Gradually it becomes compact forming network structure. Hydrated calcium aluminate and aluminium hydroxide filled in the network structure which makes the material more compact. Increasing the amount of gypsum within a certain range will promote the formation of ettringite. The lower the water cement ratio is, the more compact the ettringite is and the stronger the material is. Finally, based on the hydration products and microstructure of the material, the hydration reaction equation was established and the growth process of strength was analyzed, and it provides the basis for the study of the durability of the material.

Eight prestressed steel reinforced concrete beam (PSRCB) and six steel reinforced concrete beam (SRCB) have been done with different compressive strength of concrete, rebar ratio, cover thickness, steel cover thickness and degree of prestressing. A compared study on the mechanical properties between PSRCB and SRCB were carried out, which included flexural capacity, deflection and maximum crack width. Experimental study indicates that PSRCB has better mechanical performance, higher flexural capacity, larger stiffness and better resistance to crack.

In order to reasonably carry out dynamic analysis and seismic design of soil and soil-structure interaction system, on the basis of dynamic triaxial tests, a permanent strain potential model for saturated silty soil during seismic liquefaction is established. And it can well fit the development rule of strain during liquefaction of silty soil.

The new grouting material with advantages of early strength, strong liquidity, better expansibility and environmental protection can be applied to underground structure engineering. The effects of different w/b ratios, curing ages, limes and SiO₂ on the compressive strength of the new grouting material were investigated. By SEM and TGA-DSC analysis, its microscopic morphology and hydration products are explored. The results show that the early strength of the new grouting material develops rapidly, and the 3d compressive strength can reach 80% of the 28d compressive strength. Under the condition that the w/b ratio is 1.0, the compressive strength increases with CaO content in lime increasing. The addition of micron-SiO₂ can improve compressive strength by about 5% when the formulation is reasonable. The main hydration products of SEM-EDS are needle-like ettringite, spherical aluminum gel and amorphous C-S-H(C-A-S-H) gel, corresponding to three endothermic peaks appearing in TGA-DSC at around 90°C, 230°C and 660 °C, respectively.

The inside space of railway tunnel is complex and enclosed. The maintenance for internal lines and tunnel itself always requires lots of time, and the inspectors need to climb ladders, which is unsafe and cannot reach blind side. In this paper, a new luffing mechanism of tunnel inspection equipment is designed, and the joint of luffing mechanism is optimized. The interference is solved, and the joints load of luffing mechanism is decreased. Combined with finite element analysis, the stiffness and strength fully meet the demand. The analysis results could provide the theory guidance for the design and production of railway inspection equipment.

Poly(L-lactic acid) (PLLA) is important and biodegradable semi-crystalline polymer with promising application in industry. To estimate the effect of synthesized hydroxyapatite (HA) on the performance of PLLA, differential scanning calorimeter (DSC) and X-ray diffraction (XRD) were employed to investigate the crystallization of PLLA/HA composites. DSC showed that HA could accelerate the crystallization of PLLA, and the relationship between HA content and nucleation effect was not linear. However, 10 wt% HA had the best crystallization nucleation effect for PLLA. XRD analysis further confirmed the nucleation effect of HA, and there existed an interesting fact that the intensity of characteristic peak of PLLA/HA after isothermal became weak with an increase of HA content. XRD measurement for PLLA/0.5%HA after different isothermal temperatures showed that the crystallization temperature played important role in crystallization of PLLA.

Prestressed steel reinforced concrete beam(PSRCB) is a new type prestressed composite beam which uses prestressing technology in steel reinforced concrete beam (SRCB). The complete failure procedure of PSRCB was analysised by three-dimensional nonlinear finite element method. Numerical results agree well with experimental results. Then the numerical model was used to conduct some parametric studies including tensile rebar ratio, concrete compressive strength, H-section steel ratio, effective stress of prestressing strands and degree of prestressing.

In this paper, the effects of different steel fiber and polypropylene fiber on the mechanical properties of recycled concrete were studied. The empirical formulas for the axial compressive strength, splitting tensile strength, flexural strength and fiber content of each recycled concrete are given. The results show that the mechanical properties of recycled concrete are improved to different degrees, and the increase of splitting tensile strength is the most significant. When the steel fiber content is 2%, the increase of splitting tensile strength and flexural strength are the most significant, which are 44.8% and 34.0%, respectively; when the steel fiber content is 1.5%, the axial compressive strength has the most significant increase is 19.4%. When the polypropylene fiber content is 0.8kg/m³, the axial compressive strength, splitting tensile strength and flexural strength have the most significant increase, which are 15.8%, 40.5% and 39.6%, respectively.

In order to study the effect of warm mix agent on the mechanical properties of warm mix asphalt mixture before and after aging, this article uses the uniaxial compression test and the uniaxial dynamic modulus test which were carried out on the unaged, short-term aging and long-term aging conditions of the matrix and SBS modified asphalt mixture mixed with RH and Evotherm warm mix agent respectively. The results show: the performance of each asphalt mixture at low temperature and high frequency is equivalent, indicating that dynamic mechanics is not suitable for evaluating the low temperature performance of asphalt mixture; high temperature and low frequency can be used as an evaluation index for high temperature anti-rutting of asphalt mixture. By analyzing the rebound modulus, uniaxial dynamic modulus and other results, it shows that the addition of the warm mix agent improves the low temperature performance of the asphalt mixture, alleviates the aging of the asphalt mixture, and the aging of the aging also brings about a decrease in high temperature stability. The beneficial effect of the Evotherm is weak, and the low temperature performance of the asphalt mixture after aging and the high temperature stability of the warm asphalt mixture after long-term aging are improved. From the comprehensive analysis of static and dynamic mechanical properties, the elastic modulus and dynamic modulus of asphalt mixture are not much different, and the dynamic static modulus of the mixture after aging is quite different, which provides a theoretical basis for the dynamic and static modulus transformation.

In this paper, the influence of four main factors on the compressive strength of cement-based foam concrete is studied by orthogonal test with L_9 (3 ^ 4) orthogonal table. They are the amount of foam agent, the amount of water reducing agent, the amount of foam stabilizer and the water cement ratio. The results show that the main factors affecting the 7-day compressive strength of cement-based foam concrete are: water cement ratio > foam agent content > water reducer content > foam stabilizer content. The best test mix is: water cement ratio 0.41, foam agent 0.66%, water reducer 0.20%, foam stabilizer 0.021%. Its 7-day compressive strength is 2.65 MPa, dry density is 444 kg/m^3, water absorption rate is 23%, in line with JG/T 266-2011 "foam concrete" and JGJ/T 341-2014 "foam concrete application technical specification" stipulated in the performance requirements.

With urbanization development and the introduction of national policies, the prefabricated utility tunnel has been the future direction of the utility tunnel development due to great advantages in the quality, time and cost compared with the cast-in-place utility tunnel. This paper introduces three joint forms and analyses the main existing problems in waterproofing technology of precast utility tunnel joints. Besides, the fourth most common waterproof materials and waterproof constructions of prefabricated utility tunnel in China are discussed. This paper aims at providing some new ideas of waterproof materials and constructions for researchers and engineers, further promoting development of prefabricated utility tunnel.

Because triethanolamine (TEA) and anhydrous sodium sulfate (Na2SO4) can both improve the performance of cement stabilized macadam material, an optimal dosage group is found by compounding the two materials to improve the dry shrinkage performance of cement stabilized macadam material. Based on unconfined compression test and dry shrinkage strain test, the changes of compressive strength of water-stabilized macadam materials caused by different compound dosage groups and original materials were compared. The results show that the three dosage groups can improve compressive strength and reduce the dry shrinkage strain of the cement stabilized macadam material. The compressive strength of 2.0 % anhydrous sodium sulfate and 1.0 % triethanolamine was the best, increasing 73.8 %; moreover, the dosage group can effectively reduce shrinkage cracks, which is 3.88 % less than that of the blank control group. The test data were tested by correlation analysis and there were significant differences between the control group and each dosage group, which indicated that the admixture had a significant improvement on the material properties.

The effects of USP warm-mixed agent, Evo warm-mixed agent and aging degree on the low temperature performance and micro-morphology of SBS modified asphalt were analyzed by ductility test, bending creep stiffness test (BBR) and atomic force microscope (AFM) scan test. The test results show that: The ductility test analysis shows that USP warming agent can improve the low temperature performance of SBS modified asphalt in the positive temperature zone, and aging reduces the ductility of warm mixed asphalt, in which Evo warm mix asphalt has the strongest ability to resist thermal aging. BBR test analysis shows that USP warm mixed agent improves the low temperature performance of the negative temperature zone of SBS modified asphalt, but this improvement is limited by the aging effect, the comparison analysis found that creep loading time had a significant impact on the creep compliance derivative, it is more than the effect of warm-mixed agent, and aging can accelerate warm mix asphalt into the creep stability period; AFM micro-scanning found that the "bee-like structure" appeared on the front topography of SBS modified asphalt and Evo warm asphalt. The bee-like structure of Evo warm mix asphalt is larger and more numerous. The larger the size of the bee structure, the smaller the number of bee structures; however, the surface of the USP warm mix asphalt is more undulating; the aging of the two types of asphalt is more serious, and the size of the honeycomb structure is larger, but the number of honeycomb structure is reduced; while the surface of USP warm asphalt is undulating.

The modal analysis and verification of super large FRP combined storage tank structure without floating roof are carried out. First, the finite element model of the structure system of the super large FRP composite storage tank without floating roof is established by ADINA. Then, the modal analysis of the structure system of the super large FRP composite storage tank without floating roof is carried out. Finally, the theoretical analysis of the sloshing frequency of the liquid storage is compared with the finite element results. The results show that the larger water storage height is, the larger the sloshing frequency is, on the contrary the larger the storage tank radius is, the smaller the sloshing frequency is. The theoretical analysis of the sloshing frequency of the super large FRP storage tank system is in good agreement with the results of the finite element calculation, and the correctness of the finite element model and the analysis method of the super large FRP composite storage tank structure system is verified. The calculation formula of the basic frequency of the storage sloshing of the super large FRP combined tank system is given.

For the purpose of obtaining the axial compressive performance of the concrete filled double steel tube (CFDST) short columns, four CFDST specimens were designed in this paper. Based on a simplified bilinear constitutive model for steel and a nonlinear constitutive model considering the hoop effect for concrete, and four short columns under axial compression were established by ABAQUS finite element (FE) software which can obtain the load-displacement curves and destructive forms, by compared with the existed experimental data the rationality of finite element model is verified. These can lay the foundation for further analysis of the extended parameters and seismic performance for composite columns.

In engineering application, a kind of SBS is often used to modify the matrix asphalt, but there is less research on the application of double SBS composite modified asphalt. This paper shows through indoor testing: 3.15% Dushanzi T161B Star SBS Modifier +1.05% LCY3501 Linear SBS Modifier +3.75% Stabilizer + Tipke 70# matrix asphalt can be made into composite modified asphalt, which the high-temperature performance, ductility and anti-aging properties can be well adapted to the high temperature characteristics of Hainan Province, and the commonly used single modified asphalt has obvious economic advantages and can be widely used in Hainan.

From 2009 to 2012, 14 failure high strength bolts were found in Chaotianmen Bridge,and 11 bolts were collected on site, of which 8 bolts were pitted and rusted. The chemical composition, metallographic structure, hardness and other mechanical properties of these 11 bolts were analyzed and tested to explore the reasons for fracture failure of high strength bolts. The results show that six failure high strength bolts` HRC values are of 40, 40.5 and 43 (4 bolts), which does not meet the technical requirement of GB/T1231-2006, and the unqualified rate accounts for 54.5%. Tempered martensite, which belongs to brittle structure, was detected in metallographic structure in samples with unqualified hardness. The failure of high strength bolts is not only related to the unqualified metallographic structure, but also related to the construction processs, operating environment and other aspects. Especially the influence of environmental corrosion on the quality, micro-structure and mechanical properties of high strength bolts should be paid more attention by bridge managers. It is necessary to further explore and clarify the influence of environmental factors on the corrosion fracture of high strength bolts and its mechanism, so as to provide a basis for the measures taken to prevent the breakage of high strength bolts.

This paper mainly studies the effects of different cement content (5%, 7%, 9%, 11%, 13%, 15%) on the unconfined compressive strength of cement stabilized macadam base materials. The effects of different cement content on the compressive properties of the mixture were compared by unconfined compressive strength test analysis. The results show that the influence of cement content on the early strength of the road base layer is greater than the impact on the later strength. When the age is 1 day, the cement content increases from 9% to 11%, and the unconfined compressive strength increase rate of the test piece is the largest (35.93%).

In order to reasearch and develop more efficient anti-seismic system of high-rise building structures, a new shear wall with reinforcement of column form, concrete-filled steel tubular frames and diagonal bars was put forward in this paper. Three shear wall specimens with different structural form were designed and made, and then tested by the low-cycle loading experiment. According to the test results, anti-seismic behaviour indexes such as failure characteristics, bearing capacity, ductility, and stiffness degradation of three specimens were analized. The ABAQUS model of new shear walls was established. The experimental results show that, compared with other specimens, the anti-seismic energy dissipation capacity and bearing capacity of the shear wall specimen with reinforcement of column form, concrete-filled steel tubular frames and diagonal bars is enhanced significantly, and the process of stiffness degradation is more slow. The column-form reinforcement can improve ductility, and the concrete-filled steel tubular frames can guarantee the lateral stiffness.

Effective stress of prestressed steel bars in bridge structures is very important, and there is no compulsory requirement to test the tensile force of prestressed steel bars in bridge codes of our country. However, the lack of tensile force and failure of prestressed reinforcement will bring significant security risks. In this paper, according to the structural characteristics and anchorage characteristics of prestressed steel bar, on the basis of theoretical analysis and experiment, the curve of tension F and elongation S of single prestressed steel strand is established, which lays a foundation for effective stress detection of bridge steel bar in China.

Prestressed reinforcement is one of the most hidden and important project in bridge enginerring. It directly determines the structure of the bending, shear, anti vibration, anti impact performance, it also has influence on the safety and durability of the structure. To evaluate old bridge structure, it is required to detect the internal reinforced distribution (quantity, specifications, protection layer thickness). In addtition, due to poor construction quality, position of prestressed tendons biased, and grouting can not get guarantee, which leads to serious corrosion of prestressing tendons, consequently in potential safety hazard. All above indicate that by using nondestructive method, it is significant to locate the prestressed tendon and define the quantative and distribution in structure. Then, it is required to evaluate the grouting condition of prestressed ducts, and regrouting for the flaw ducts. This paper focuses on several current famous prestressed grouting nondestructive detection methods, combining the characteristics of the actual bridge structure, and the accuracy of each method is obtained. Results is compared with applicability and pertinency. Research results provide method and basis for detecting subsequent prestressed bridge.

The three-dimensional finite element model of pre-stressed concrete continuous girder bridge with span (76+144+76)m is established by using finite element structural analysis software Ansys in this paper. The dynamic time history analysis method is used to study the influence of viscous dampers and friction pendulums with different parameters on the seismic response of long-span continuous beam bridges, which provides a basis for rational selection of seismic isolation measures. The results show that reasonable seismic isolation measures can effectively reduce the seismic response of long-span continuous beam bridges; both the viscous damper and the friction pendulum can have good seismic isolation effects, but the damping effects are related to their parameter settings.

The seismic problem of long-span arch bridges has attracted great attention at home and abroad in recent years and the technology of seismic isolation provides an effective way for seismic protection of long-span arch bridges. In this article, a practical arch bridge is taken as the object of research. The parameters of the friction pendulum support and buckling-restrained brace are analyzed, and the damping effect of friction pendulum support, buckling-restrained brace and friction pendulum support combined with buckling-restrained brace are compared and analyzed. It turns out that the friction pendulum support and the buckling-restrained brace have a good damping effect on the seismic response of the transverse bridge, and the damping effect on the inward force and displacement response of the arch bridge which applies both friction pendulum support and the buckling-restrained brace is better than that of the bridge which applies the friction pendulum support or buckling-restrained brace alone.

The selection of damage index is not only the premise and basis for structural vulnerability analysis, but also plays an important role in the accuracy of structural damage assessment. Jinsha River long-span suspension bridge under construction is taken as the research object in this paper. Based on the OpenSees program, the selection of the damage index of the suspension bridge tower is studied. The influence of axial force change on the bending moment-curvature is analyzed by XTRACT software. The applicability of material strain as an indicator of bridge tower damage is studied by IDA analysis. The results show that the material strain is the most reasonable damage index for evaluating the damage of the bridge tower compared to the top displacement and the section curvature.

In this paper, the principle of energy dissipation of anti-buckling support and the simulation method in finite element are introduced. A large-span steel truss deck type arch bridge with a large span is selected as the research object. Based on the analysis of seismic response characteristics, the anti-buckling restraint support is used to systematically study the damping control of long-span steel truss arch bridges. By comparing the seismic responses of the arch bridges before and after the anti-buckling support, the arrangement position of the anti-buckling support was optimized, and the damping effect of anti-buckling support was analyzed. The results show that the reasonable anti-buckling arrangement has better damping effect for long-span arch bridges, but the damping effect of anti-buckling support under different arrangements is quite different.

The formation and development of plastic hinge have a great influence on the seismic response of long-span rigid frame bridges. Therefore, it's especially important to study the development process of plastic hinges under ground motion. Based on the OpenSees software, the elastic-plastic finite element model of long-span rigid frame bridge is established, the influence of pier design parameters on plastic hinge is studied from the perspective of IDA analysis. Meanwhile, the advantages and disadvantages of lumped plastic hinge and distributed plastic hinge are discussed in two groups of bending failure pier of "Pseudo-static test on bridge pier of chengdu-lanzhou railway". The results show that the accuracy of distributed plastic hinge element simulation is higher than lumped plastic hinge; and with the increase of pier height and longitudinal reinforcement ratio, the PGA with plastic hinge in the section will increase for the first time.

This project is the building of LOFT system. Due to the high height and large width of the building, the structural design is been challenged. How to use a reasonable structure system on the premise of ensuring the safety of the structure to make the building and structure perfectly unified is the main goal of this engineering structure design. In this paper, according to the irregularity of the multiple structure, the author determined the corresponding seismic performance targets and analyzed the performance indexes of the structure in small earthquakes, medium earthquakes and rare earthquakes. The whole structure is calculated and analyzed, and the stress of the partial floor is calculated, so as to give the damage degree of each member of the high-rise building, and judge whether it meets the earlier development of the corresponding performance target. For this kind of high-rise building, it is an effective design idea to adopt performance-based seismic design method. According to the importance of components, corresponding seismic design methods and corresponding performance objectives are formulated and verified by appropriate analysis methods.

The problem of low frequency vibration and noise control is a huge challenge in the engineering environment. The bandgap characteristics of phononic crystals can suppress the propagation of acoustic waves and provide a new solution for low-frequency vibration and noise control. In this paper, an acoustic supermaterial structure plate is proposed. By the finite element calculation, two band gaps of 71Hz∼120Hz and 315Hz∼400Hz are obtained. Finite element method is used to analyze the variation of the transverse and longitudinal periodic number of the acoustic supermaterial plate, and the relationship between the vibration transmission characteristics and the band gap is obtained. The research shows that the number of original cells of acoustic metamaterial structural plates is at least 8.

CoCrMo alloy is an excellent material for manufacturing prosthesis. Due to the complex body environment, the prosthesis has a higher requirement for surface abrasion resistance and corrosion resistance. In this paper, the friction and wear properties of CoCrMo alloy artificial prosthesis were studied by a ring block friction-wear testing machine. The results indicate that the friction coefficient of CoCrMo alloy decreases with the increase of the load and rotation speed. The wear mass of the CoCrMo alloy has a good wear resistance and is suitable for manufacturing prosthesis. However, the surface of the CoCrMo alloy partially cracks under heavy load through SEM analysis, which indicates the prosthesis is not suitable for patients who often engage in heavy carrier forces.

With the development of industrialization technology, the variety of plastic products has increased and the product application fields have become more and more extensive. People also have higher and higher requests for the quality of plastic products. The traditional molding process has been difficult to meet the requirements of the recent high standards, which promotes the continuous innovation of plastic molding technology, and advanced molding technologies are emerging. This paper introduces several advanced technologies of molding processing at home and abroad and provide an outlook of the development prospects of technology in this field.

In this paper, a high speed reconfigurable control bits generation algorithm for cyclic shift operations is proposed. The algorithm utilizes the characteristics of routing information when Inverse Butterfly multi level network supports cyclic shift. Moreover, it also integrates a kind of cyclic shift operations together, including cyclic shift and sub-word cyclic shift based on a bit width of 2ⁱ(i = 1, 2, ...). Based on this, the shifter is implemented, and the logic synthesis is realized in the SMIC 65nm process. The results show that when the proposed unit only supports cyclic shift operations, enhances the frequency by 3.6% ∼ 8.6% and reduces the area by1.4% ∼ 32%, compared with previously proposed solutions. When achieving a variety of cyclic shift operations, the frequency of our unit enhances the frequency by 5% and reduces the area by 6%.

Mixer rotor speed is one of the important factors which effects the mixing process and mixer rotor speed of SFRC greatly. The effects of different mixer rotor speed on mixing process of SFRC have been researched by experiments. In the paper, the mixer rotor speed was changed from 50rpm to 80rpm respectively. And also the addition of short fibers was about 0phr∼6phr. The experimental results indicated that SFRC had better physical and mechanical properties as mixer rotor speed was about 70rpm, and the addition of short fibers was about 3phr.

Roof bolt pressure is one of the important factors which impacts the mixing process and roof bolt pressure of SFRC greatly. The effects of different roof bolt pressure on mixing process of SFRC have been researched by experiments. In the paper, the roof bolt pressure was changed from 0.3MPa to 0.6MPa respectively. And also the addition of short fibers was about 0phr∼6phr. The experimental results indicated that SFRC had better physical and mechanical properties as roof bolt pressure was about 0.6MPa, and the addition of short fibers was about 3phr.

Turnouts are key line equipment for suspended monorail transit. In order to determine the reasonable line type of the symmetrical suspension monorail turnout, a dynamic model of the multi-degree-of-freedom (MDOF) suspended monorail transit system is established according to the multi-body dynamics theory, and the influence of the radius of the circular curve and the length of straight between two curves on the dynamic performance of the vehicle passing the turnout is analyzed. The research findings show that: The turnout should be the turnout #5 with the frog angle is 11°18'36'', and the line shape of the circular curve and the straight line should be used. The radius of the circular curve can affect the dynamic performance of the vehicles passing the turnout greatly, and should not be less than 50 m. The length of straight between two curves has little influence on the dynamic performance, but it should be greater than 6.6 m.

Turnouts is a key line equipment for suspended monorail transit. In order to analyze the dynamic performance of vehicles passing turnouts, a dynamic model of the multi-degree-of-freedom (MDOF) suspended monorail transit system is established according to the multi-body dynamics theory by taking turnout #5 as an example. The effect of track irregularity on the dynamic performance of Shanghai sky train transformation (SSTT) bogie vehicle passing the turnout is analyzed; a contrast analysis on the dynamic performances of SSTT vehicle and Prose associated bogie vehicles passing the turnout is made. The research findings show that: the deformation of bridges and subsidence of piers can affect the dynamic performance of the vehicles passing the turnout greatly. When an SSTT bogie vehicle is passing the turnout in side move, the maximum guidance force difference of the guide wheels will reach up to 171%; when a Prose associated bogie vehicle is passing the suspended sky train turnout in side / trailing move, the dynamic performance of which can be better than that of the SSTT bogie vehicle and the operation can be more stable.

Fiber Reinforced Polymer Concrete composite materials have been widely used in many fields of engineering, it is necessary to research the crack propagation process of Fiber Reinforced Polymer Concrete composite material in the high temperature by Numerical Simulation. the numerical model is applied to investigate the formation, extension and coalescence and crack propagation in Fiber reinforced polymer reinforced concrete composites in the high temperature, the deformation and damage evolution are briefly described in the model, a numerical model of fiber reinforced polymers embedded in Concrete is proposed to investigate thermally-induced damage and crack propagation in the high temperature, the numerical Simulation show that the crack propagation behavior of the Fiber Reinforced Polymer Concrete composite material in the high temperature is developed at the interface between the Fiber Reinforced Polymer and Concrete, the numerical simulation demonstrates that the model proposed can visually replicate the thermal cracking propagation process of Concrete and the simulated cracking of Concrete is in good agreement with the experimental cracking result of Fiber Reinforced Polymer Concrete composite material in the high temperature.