The functions,applications,developments and current application mode of IDS3.x system are generally introduced in this paper.Then the development mode of spacecraft based on IDS3.x system is described.The existing pro...The functions,applications,developments and current application mode of IDS3.x system are generally introduced in this paper.Then the development mode of spacecraft based on IDS3.x system is described.The existing problems especially the information redundancy of mechanical interface and their effects are pointed out.A new solution is proposed by developing 3D-IDS system.The central functions of 3D-IDS system are shown in this study.A new application mode of 3D-IDS system is explored and described by showing how to fill in,countersign and apply with 3D-IDS file.The 2D drawing and sketch are removed from 3D-IDS system to avoid information redundancy of mechanical interface.The consistency between 3D model and the parameters of IDS file can be guaranteed by the interface tool.The efficiency of filling in,countersigning and applying,has been improved significantly,which greatly promotes the coordination and total efficiency of spacecraft system design departments and unit design departments.展开更多
The pre-wetting of aggregate surface is a means to improve the interface performance of SBS modified asphalt and aggregate.The effect of pre-wetting technology on the interaction between SBS modified asphalt and aggre...The pre-wetting of aggregate surface is a means to improve the interface performance of SBS modified asphalt and aggregate.The effect of pre-wetting technology on the interaction between SBS modified asphalt and aggregate was analyzed by molecular dynamics simulation.The diffusion coefficient and concentration distribution of SBS modified asphalt on aggregate surface are included.The simulation results show that the diffusion coefficient of the aggregate surface of SBS modified asphalt is increased by 47.6%and 70.5%respectively after 110#asphalt and 130#asphalt are pre-wetted.The concentration distribution of SBS modified asphalt on the aggregate surface after pre-wetting is more uniform.According to the results of interface energy calculation,the interface energy of SBS modified bitumen and aggregate can be increased by about 5%after pre-wetting.According to the results of molecular dynamics simulation,the pre-wetting technology can effectively improve the interface workability of SBS modified bitumen and aggregate,so as to improve the interface performance.展开更多
Understanding the mechanical behavior of diagenetic mineral granules and interfaces in granite provides essential experimental references for constructing micromechanical models of granite.The micromechanical behavior...Understanding the mechanical behavior of diagenetic mineral granules and interfaces in granite provides essential experimental references for constructing micromechanical models of granite.The micromechanical behavior of Yanshanian granite is investigated using scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS)and nanoindentation tests.The results demonstrate transitional mechanical properties at mineral interfaces.The elastic modulus and hardness exhibit intermediate values between adjacent mineral phases.The higher plasticity indices at the interfaces suggest higher plastic deformation capacity of hard-phase minerals in these regions.Additionally,fracture toughness measurements of minerals and interfaces were obtained,with interfacial values ranging from 0.90 to 1.63 MPa·m^(0.5).The analysis of mechanical property relationships shows a significant positive linear correlation between rock-scale elastic modulus and fracture toughness.However,this correlation is substantially lower at the mineral scale,demonstrating a scale effect in the relationship of different mechanical properties.展开更多
Stop-start vehicles(SSVs)represent a potential alternative for improving internal combustion engine(ICE)efficiency.SSVs provide ICEs with the functionality of turning the engine off during traffic halts and restarting...Stop-start vehicles(SSVs)represent a potential alternative for improving internal combustion engine(ICE)efficiency.SSVs provide ICEs with the functionality of turning the engine off during traffic halts and restarting it without intervention by the driver.This strategy reduces fuel consumption,especially in dense urban traffic areas,and contributes to emissions reduction to meet green emissions targets.The most widely adopted SSV system has a mechanical interface to connect the electric starter motor to the ICE,which requires increased robustness compared with standard starting motors.This requirement allows the motor to withstand a higher number of engine start cycles compared with a standard starting motor.Nevertheless,it is a critical problem for wider adoption of SSVs.As SSV systems usually are based on the conventional starting system,its durability and noise remains a critical issue to be addressed by automakers.The typical pinion-ring gear interface uses intermittent gear meshing to form a transient coupling interface.The research reported here presents the development of an innovative mechanical interface for starting systems,called the permanent coupling(PC)-type interface,which reduces noise and increases durability compared with the existing design.The results obtained by a functional prototype of the PC-type mechanical interface confirm the feasibility of the proposed concept.The methodology is based on a product development process integrated with lumped-parameter modeling and virtual simulation aimed at reducing failures during prototype test-ing.The new mechanical interface was proven to be a good candidate for increasing the use of SSVs in the automotive market.展开更多
Magnetic levitation is a non-self-stabilizing system that requires high control performance.The system's stability is affected by the mechanical interface between the levitation object and the loading device,with ...Magnetic levitation is a non-self-stabilizing system that requires high control performance.The system's stability is affected by the mechanical interface between the levitation object and the loading device,with self-excited vibration generated in the operation process.This paper proposes to consider the mechanical behavior of the contact interface in the magnetic levitation system.Since electromagnetic and control systems are mechanically equivalent,the coupled electric-magnetic-mechanical model is established by adopting the lumped mechanical modeling method.Furthermore,the effect of the contact clearance on the mechanical behavior of the system is analyzed using the Routh-Hurwitz theory.The research results show that with the decrease in the contact clearance,the vibration frequency increases.When the vibration frequency exceeds the critical value,a continuous vibration phenomenon occurs in the system under the joint action of feedback and energy mechanisms.Finally,the effect of interface parameters on the vibration characteristics is analyzed using the fourth-order Runge-kutta numerical method.The analyses show that the interface contact leads to combination frequency and frequency multiplication components in the coupled system.展开更多
Bio-nano interfaces between biological materials and functional nanodevices are of vital importance in relevant energy and information exchange processes, which thus demand an in-depth understanding. One of the critic...Bio-nano interfaces between biological materials and functional nanodevices are of vital importance in relevant energy and information exchange processes, which thus demand an in-depth understanding. One of the critical issues from the application viewpoint is the stability of the bio-nano hybrid under mechanical perturbations. In this work we explore mechanical responses of the interface between lipid bilayer and graphene under hydrostatic coating provides remarkable resistance to the pressure or indentation loads, We find that graphene loads, and the intercalated water layer offers additional protection. These findings are discussed based on molecular dynamics simulation results that elucidate the molecular level mechanisms, which provide a basis for the rational design of bionanotechnology- enabled aoolications such as biomedical devices and nanotheraoeutics.展开更多
This paper investigates the interface mechanical behavior of flexible piles with L_p/D>10 under lateral load and an overturning moment in monotonic loading conditions.To modify the beam-on-Winkler-foundation model ...This paper investigates the interface mechanical behavior of flexible piles with L_p/D>10 under lateral load and an overturning moment in monotonic loading conditions.To modify the beam-on-Winkler-foundation model of piles in offshore wind farms,the energy-based variational method is used.The soil is treated as a multi-layered elastic continuum with the assumption of three-dimensional displacements,the pile modeled as an Euler-Bernoulli beam.A series of cases using MATLAB programming was conducted to investigate the simplified equations of initial stiffness.The results indicated that the interaction between soil layers and the applied force position should be taken into account in calculating the horizontal soil resistance.Additionally,the distributed moment had a limiting effect on the lateral capacity of a flexible pile.Moreover,to account for the more realistic conditions of OWT systems,field data from the Donghai Bridge offshore wind farm were used.展开更多
This paper developed a hot Pressing aided exothermic synthesis (HPES) technique. to fabricate NiAl matrix composites containing 0 and 20 v.% TiB_2 particles. The conversion to the product was complete. and TiB_2 parti...This paper developed a hot Pressing aided exothermic synthesis (HPES) technique. to fabricate NiAl matrix composites containing 0 and 20 v.% TiB_2 particles. The conversion to the product was complete. and TiB_2 particles in the matrix were uniformly dispersed. The inter faces between nail and TiB_2 were atomically flat. sharp and free from any inter facial phases in most cases. In some cases. however. thin inter facial amorphous layers existed at NiAl/ TiB_2 interfaces. In addition, the microstructure and inter faces were highly thermal stable. In all processing states. the yield strengths at room temperature or at 1000℃ of the composite were approximately three times as strong as that of the unrein forced NiAl. The ambient fracture toughness of the composite was also superior to monolithic NiAl.展开更多
Currently for the steel tube reinforced concrete composite pile research, although predecessors make a comprehensive research on the composite pile beating performance, design technology, but there are still many prob...Currently for the steel tube reinforced concrete composite pile research, although predecessors make a comprehensive research on the composite pile beating performance, design technology, but there are still many problems have not been solved, such as the steel tube reinforced concrete pile composite interracial force learn performance research is still in the initial stage. In this paper, we mainly discuss the research methods of several interface mechanical properties and propose the possibility of studying the mechanical properties of the steel tube reinforced concrete composite pile by using the principle of ultrasonic speckle.展开更多
We outline problems and potential solutions for feasible human-machine interfaces using cable-based parallel manipulators for physiotherapy applications.From an engineering perspective,we discuss the design constraint...We outline problems and potential solutions for feasible human-machine interfaces using cable-based parallel manipulators for physiotherapy applications.From an engineering perspective,we discuss the design constraints related to acceptance by patients and physiotherapist users.To date,most designs have focused on mobile platforms that are designed to be operated as an end-effector connected to human limbs for direct patient interaction.Some specific examples are illustrated from the authors' experience with prototypes available at Laboratory of Robotics and Mechatronics (LARM),Italy.展开更多
The modeling and self-excited vibration mechanism in the magnetic levitation-collision interface coupling system are investigated.The effects of the control and interface parameters on the system's stability are a...The modeling and self-excited vibration mechanism in the magnetic levitation-collision interface coupling system are investigated.The effects of the control and interface parameters on the system's stability are analyzed.The frequency range of self-excited vibrations is investigated from the energy point of view.The phenomenon of self-excited vibrations is elaborated with the phase trajectory.The corresponding control strategies are briefly analyzed with respect to the vibration mechanism.The results show that when the levitation objects collide with the mechanical interface,the system's vibration frequency becomes larger with the decrease in the collision gap;when the vibration frequency exceeds the critical frequency,the electromagnetic system continues to provide energy to the system,and the collision interface continuously dissipates energy so that the system enters the self-excited vibration state.展开更多
Roots play an important role in stabilizing and strengthening soil. This article aims to study the mechanical properties of the interface between soil and roots with branches, using the pullout test method in the labo...Roots play an important role in stabilizing and strengthening soil. This article aims to study the mechanical properties of the interface between soil and roots with branches, using the pullout test method in the laboratory. The mechanical properties of the soil-root with branches interface is determined through the pullout-force and root-slippage curve （F-S curve）. The results of investigating 24 Pinus tabulaeformis single roots and 55 P. tabulaeformis roots with branches demonstrated three kinds of pullout test failures： breakage failure on branching root, breakage failure on branching node, and pullout failure. The branch angle had a remarkable effect on the failure mode of the roots with branches： the maximum pullout force increased with the sum of the branch diameters and the branch angle. The peak slippage and the initial force had a positive correlation with the sum of the branch diameter. The sig- nificance test of correlation between branch angle and the initial force, however, showed they had no correlation. Branch angle and branch root diameter affect the anchorage properties between root system and soil. Therefore, it is important to investigate the anchorage mechanics of the roots with branches to understand the mechanism of root reinforcement and anchorage.展开更多
To investigate the dynamic behavior and energy dissipation of the rock−concrete interface,dynamic splitting tests on bi-material discs were conducted by using the split Hopkinson pressure bar.The test results reveal t...To investigate the dynamic behavior and energy dissipation of the rock−concrete interface,dynamic splitting tests on bi-material discs were conducted by using the split Hopkinson pressure bar.The test results reveal that with the change of the interface inclination angles(θ),the influence of interface groove width on the bearing capacity of specimens also varies.Whenθincreases from 0°to 30°,the bearing capacity of the specimen increases first and then decreases with the rise of the interface groove width;the optimal groove width on the rock surface in this range of interface inclination angles is 5 mm.Whenθincreases from 45°to 90°,the bearing capacity of the specimen has no obvious change.Moreover,whenθincreases from 0°to 45°,the dissipated energy of the specimens rises obviously at first and then tends to be stable as the width of the interface groove increases.展开更多
Calcium sulfate whiskers（CSWs） modified with glutaraldehyde-crosslinked poly（vinyl alcohol）（PVA） or traditional surface modifiers,including silane coupling agent,titanate coupling agent and stearic acid,were use...Calcium sulfate whiskers（CSWs） modified with glutaraldehyde-crosslinked poly（vinyl alcohol）（PVA） or traditional surface modifiers,including silane coupling agent,titanate coupling agent and stearic acid,were used to strengthen poly（vinyl chloride）（PVC）,and the morphologies,mechanical and heat resistant properties of the resulting composites were compared.The results clearly show that glutaraldehyde cross-linked PVA modified CSW/PVC composite（c PVA@CSW/PVC） has the strongest interfacial interaction,good and stable mechanical and heat resistant properties.Nielsen＇s modified Kerner＇s equation for Young＇s modulus is better than other models examined for the CSW/PVC composites.The half debonding angle θ of c PVA@CSW/PVC composite is lower than that of other composites except silane coupling agent modified CSW/PVC composites,indicating a very strong interfacial adhesion between c PVA@CSW and PVC.In general,cross-linked PVA is effective and environmentally friendly in modifying inorganic fillers.展开更多
In this work, low-carbon steel specimens were subjected to the quenching and partitioning process after being partially or fully austenitized to investigate their microstructural evolution and mechanical properties. A...In this work, low-carbon steel specimens were subjected to the quenching and partitioning process after being partially or fully austenitized to investigate their microstructural evolution and mechanical properties. According to the results of scanning electron microscopy and transmission electron microscopy observations, X-ray diffraction analysis, and tensile tests, upper bainite or tempered martensite appears successively in the microstructure with increasing austenitization temperature or increasing partitioning time. In the partially austenitized specimens, the retained austenite grains are carbon-enriched twice during the heat treatment, which can significantly stabilize the phases at room temperature. Furthermore, after partial austenitization, the specimen exhibits excellent elongation, with a maximum elongation of 37.1%. By contrast, after full austenitization, the specimens exhibit good ultimate tensile strength and high yield strength. In the case of a specimen with a yield strength of 969 MPa, the maximum value of the ultimate tensile strength reaches 1222 MPa. During the partitioning process, carbon partitioning and carbon homogenization within austenite affect interface migration. In addition, the volume fraction and grain size of retained austenite observed in the final microstructure will also be affected.展开更多
For a special geological structure of columnar jointed rock mass(CJRM),its mechanical properties are strongly affected by the columnar joints.To describe the fracture behaviors of CJRM using the basic theories of inte...For a special geological structure of columnar jointed rock mass(CJRM),its mechanical properties are strongly affected by the columnar joints.To describe the fracture behaviors of CJRM using the basic theories of interface mechanics for composite materials,the interface stresses of the vertical and horizontal joints,which are the two primary joints in the CJRM under triaxial compression,are studied,and their mathematical expressions are derived based on the superposition principle.Based on the obtained interface stresses of the vertical and horizontal joints in the CJRM,the crack initiation of the joint interface in the CJRM is studied using the maximum circumferential stress theory in fracture mechanics.Moreover,based on this investigation,the fracture behaviors of CJRM are analyzed.According to the results of similar material physical model tests for the CJRM,the theoretical study is verified.Finally,the influence of the mechanical parameters of the CJRM on the joint interface stress is discussed comprehensively.展开更多
Diamond particles reinforced aluminum–silicon matrix composites,abbreviated as Al（Si）/diamond composites,were fabricated by squeeze casting.The effect of Si content on the microstructure and mechanical properties o...Diamond particles reinforced aluminum–silicon matrix composites,abbreviated as Al（Si）/diamond composites,were fabricated by squeeze casting.The effect of Si content on the microstructure and mechanical properties of the composites were investigated.The mechanical properties are found to increase monotonically with Si content increasing up to 7.0 wt%.The Al-7.0 wt% Si/diamond composite exhibits tensile strength of 78 MPa,bending strength of 230 MPa,and compressive strength of426 MPa.Al–Si eutectic phases are shown to connect with Al matrix and diamond particles tightly,which is responsible for the enhancement of mechanical properties in the Al（Si）/diamond composites.展开更多
Laser fusion brazing welding was proposed.Galvanized steel/AA6061 lapped joint was obtained by laser fusion brazing welding technique using the laser-induced aluminium molten pool spreading and wetting the solid steel...Laser fusion brazing welding was proposed.Galvanized steel/AA6061 lapped joint was obtained by laser fusion brazing welding technique using the laser-induced aluminium molten pool spreading and wetting the solid steel surface.Wide joint interface was formed using the rectangular laser beam coupled with the synchronous powder feeding.The result showed that the tiny structure with the composition of a-Al and Al–Si eutectic was formed in the weld close to the Al side.And close to the steel side,a layer of compact Fe–Al–Si intermetallics,including the Al-rich FeAl3,Fe2Al5 phases and Al–Fe–Si s1 phase,was generated with the thickness of about 10–20 lm.Transverse tensile shows the brittlefractured characteristic along to the seam/steel interface with the maximum yield strength of 152.5 MPa due to the existence of hardening phases s1 and Al–Fe intermetallics.展开更多
The deformation and micro-voids formation mechanisms in ferrite / bainite（ F / B） multi-phase steel with the volume fraction of bainite less than 50% were studied by numerical simulation and experimental observation...The deformation and micro-voids formation mechanisms in ferrite / bainite（ F / B） multi-phase steel with the volume fraction of bainite less than 50% were studied by numerical simulation and experimental observation. The results show that the micro-strain concentrates at the soft / hard phase（ F / B） interface in the multi-phase steel,which should be correlated with the mechanism of incoordinate deformation. During the necking of the steel,the micro-voids initially form around the F / B interface,which also form in ferrite and bainite with the severe strain. The micro-voids in bainite are more dense and finer than those in ferrite. The failure mechanism of bainite is the coalescence of micro-voids,and the failure mechanism of ferrite is the growth and tearing of micro-voids. Due to the different failure mechanisms of ferrite and bainite,a suitable part of soft phase would be beneficial to the capability of anti-failure of F / B multi-phase steel during the ductile fracture.展开更多
Based on the two-pass differential temperature rolling bonding method,the effects of prefabricated steel/aluminum composite panel temperature on interface characteristics and microstructure properties were investigate...Based on the two-pass differential temperature rolling bonding method,the effects of prefabricated steel/aluminum composite panel temperature on interface characteristics and microstructure properties were investigated through experimental analysis and finite element simulations.When the temperature exceeds 400℃,the effective preparation of the steel-aluminum transition joint can be achieved,and with the increase in temperature,the interface shear and pull-off strength of the steel-aluminum transition joint exhibits an initial decrease followed by an increase.Both the interface shear and pull-off fractures are in 1060 aluminum matrix.As the temperature increases,the size of the average grain in 1060 aluminum matrix increases and then decreases.When the temperature reaches 550℃,the comprehensive performance of the prepared steel-aluminum transition joint is the best,with the interface shear strength of 77 MPa and the interface pull-off strength of 153 MPa,exceeding the bonding strength of the explosive compounding method.There are no pinholes,wrinkles,or cracks in the lateral bending matrix and the interface.展开更多
文摘The functions,applications,developments and current application mode of IDS3.x system are generally introduced in this paper.Then the development mode of spacecraft based on IDS3.x system is described.The existing problems especially the information redundancy of mechanical interface and their effects are pointed out.A new solution is proposed by developing 3D-IDS system.The central functions of 3D-IDS system are shown in this study.A new application mode of 3D-IDS system is explored and described by showing how to fill in,countersign and apply with 3D-IDS file.The 2D drawing and sketch are removed from 3D-IDS system to avoid information redundancy of mechanical interface.The consistency between 3D model and the parameters of IDS file can be guaranteed by the interface tool.The efficiency of filling in,countersigning and applying,has been improved significantly,which greatly promotes the coordination and total efficiency of spacecraft system design departments and unit design departments.
基金Funded by the Research Funds of China University of Mining and Technology(No.102523215)。
文摘The pre-wetting of aggregate surface is a means to improve the interface performance of SBS modified asphalt and aggregate.The effect of pre-wetting technology on the interaction between SBS modified asphalt and aggregate was analyzed by molecular dynamics simulation.The diffusion coefficient and concentration distribution of SBS modified asphalt on aggregate surface are included.The simulation results show that the diffusion coefficient of the aggregate surface of SBS modified asphalt is increased by 47.6%and 70.5%respectively after 110#asphalt and 130#asphalt are pre-wetted.The concentration distribution of SBS modified asphalt on the aggregate surface after pre-wetting is more uniform.According to the results of interface energy calculation,the interface energy of SBS modified bitumen and aggregate can be increased by about 5%after pre-wetting.According to the results of molecular dynamics simulation,the pre-wetting technology can effectively improve the interface workability of SBS modified bitumen and aggregate,so as to improve the interface performance.
基金funded by the National Natural Science Foundation of China(Nos.52422403 and U22A20166)the Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project(No.2024ZD1003903)+1 种基金the Department of Science and Technology of Guangdong Province(No.2019ZT08G315)Guangdong Basic and Applied Basic Research Foundation(No.2023A1515012654).
文摘Understanding the mechanical behavior of diagenetic mineral granules and interfaces in granite provides essential experimental references for constructing micromechanical models of granite.The micromechanical behavior of Yanshanian granite is investigated using scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS)and nanoindentation tests.The results demonstrate transitional mechanical properties at mineral interfaces.The elastic modulus and hardness exhibit intermediate values between adjacent mineral phases.The higher plasticity indices at the interfaces suggest higher plastic deformation capacity of hard-phase minerals in these regions.Additionally,fracture toughness measurements of minerals and interfaces were obtained,with interfacial values ranging from 0.90 to 1.63 MPa·m^(0.5).The analysis of mechanical property relationships shows a significant positive linear correlation between rock-scale elastic modulus and fracture toughness.However,this correlation is substantially lower at the mineral scale,demonstrating a scale effect in the relationship of different mechanical properties.
基金ZEN S.A.Indus-tria Metalurgica(www.zensa.com.br)for sponsoring and funding the project.
文摘Stop-start vehicles(SSVs)represent a potential alternative for improving internal combustion engine(ICE)efficiency.SSVs provide ICEs with the functionality of turning the engine off during traffic halts and restarting it without intervention by the driver.This strategy reduces fuel consumption,especially in dense urban traffic areas,and contributes to emissions reduction to meet green emissions targets.The most widely adopted SSV system has a mechanical interface to connect the electric starter motor to the ICE,which requires increased robustness compared with standard starting motors.This requirement allows the motor to withstand a higher number of engine start cycles compared with a standard starting motor.Nevertheless,it is a critical problem for wider adoption of SSVs.As SSV systems usually are based on the conventional starting system,its durability and noise remains a critical issue to be addressed by automakers.The typical pinion-ring gear interface uses intermittent gear meshing to form a transient coupling interface.The research reported here presents the development of an innovative mechanical interface for starting systems,called the permanent coupling(PC)-type interface,which reduces noise and increases durability compared with the existing design.The results obtained by a functional prototype of the PC-type mechanical interface confirm the feasibility of the proposed concept.The methodology is based on a product development process integrated with lumped-parameter modeling and virtual simulation aimed at reducing failures during prototype test-ing.The new mechanical interface was proven to be a good candidate for increasing the use of SSVs in the automotive market.
基金supported by the National Natural Science Foundation of China(Grant No.12372005)。
文摘Magnetic levitation is a non-self-stabilizing system that requires high control performance.The system's stability is affected by the mechanical interface between the levitation object and the loading device,with self-excited vibration generated in the operation process.This paper proposes to consider the mechanical behavior of the contact interface in the magnetic levitation system.Since electromagnetic and control systems are mechanically equivalent,the coupled electric-magnetic-mechanical model is established by adopting the lumped mechanical modeling method.Furthermore,the effect of the contact clearance on the mechanical behavior of the system is analyzed using the Routh-Hurwitz theory.The research results show that with the decrease in the contact clearance,the vibration frequency increases.When the vibration frequency exceeds the critical value,a continuous vibration phenomenon occurs in the system under the joint action of feedback and energy mechanisms.Finally,the effect of interface parameters on the vibration characteristics is analyzed using the fourth-order Runge-kutta numerical method.The analyses show that the interface contact leads to combination frequency and frequency multiplication components in the coupled system.
基金supported by the National Natural Science Foundation of China (11222217 and 11472150)
文摘Bio-nano interfaces between biological materials and functional nanodevices are of vital importance in relevant energy and information exchange processes, which thus demand an in-depth understanding. One of the critical issues from the application viewpoint is the stability of the bio-nano hybrid under mechanical perturbations. In this work we explore mechanical responses of the interface between lipid bilayer and graphene under hydrostatic coating provides remarkable resistance to the pressure or indentation loads, We find that graphene loads, and the intercalated water layer offers additional protection. These findings are discussed based on molecular dynamics simulation results that elucidate the molecular level mechanisms, which provide a basis for the rational design of bionanotechnology- enabled aoolications such as biomedical devices and nanotheraoeutics.
基金financially supported by the National Natural Science Foundation of China (Grant Nos.52201324,52078128,and 52278355)the Natural Science Foundation of the Jiangsu Higher Education Institution of China (Grant No.22KJB560015)。
文摘This paper investigates the interface mechanical behavior of flexible piles with L_p/D>10 under lateral load and an overturning moment in monotonic loading conditions.To modify the beam-on-Winkler-foundation model of piles in offshore wind farms,the energy-based variational method is used.The soil is treated as a multi-layered elastic continuum with the assumption of three-dimensional displacements,the pile modeled as an Euler-Bernoulli beam.A series of cases using MATLAB programming was conducted to investigate the simplified equations of initial stiffness.The results indicated that the interaction between soil layers and the applied force position should be taken into account in calculating the horizontal soil resistance.Additionally,the distributed moment had a limiting effect on the lateral capacity of a flexible pile.Moreover,to account for the more realistic conditions of OWT systems,field data from the Donghai Bridge offshore wind farm were used.
文摘This paper developed a hot Pressing aided exothermic synthesis (HPES) technique. to fabricate NiAl matrix composites containing 0 and 20 v.% TiB_2 particles. The conversion to the product was complete. and TiB_2 particles in the matrix were uniformly dispersed. The inter faces between nail and TiB_2 were atomically flat. sharp and free from any inter facial phases in most cases. In some cases. however. thin inter facial amorphous layers existed at NiAl/ TiB_2 interfaces. In addition, the microstructure and inter faces were highly thermal stable. In all processing states. the yield strengths at room temperature or at 1000℃ of the composite were approximately three times as strong as that of the unrein forced NiAl. The ambient fracture toughness of the composite was also superior to monolithic NiAl.
文摘Currently for the steel tube reinforced concrete composite pile research, although predecessors make a comprehensive research on the composite pile beating performance, design technology, but there are still many problems have not been solved, such as the steel tube reinforced concrete pile composite interracial force learn performance research is still in the initial stage. In this paper, we mainly discuss the research methods of several interface mechanical properties and propose the possibility of studying the mechanical properties of the steel tube reinforced concrete composite pile by using the principle of ultrasonic speckle.
基金supported by the research project RORAS 2 of the Mediterranean Program funded by INRIA,France
文摘We outline problems and potential solutions for feasible human-machine interfaces using cable-based parallel manipulators for physiotherapy applications.From an engineering perspective,we discuss the design constraints related to acceptance by patients and physiotherapist users.To date,most designs have focused on mobile platforms that are designed to be operated as an end-effector connected to human limbs for direct patient interaction.Some specific examples are illustrated from the authors' experience with prototypes available at Laboratory of Robotics and Mechatronics (LARM),Italy.
基金Project supported by the National Natural Science Foundation of China(No.12372005)。
文摘The modeling and self-excited vibration mechanism in the magnetic levitation-collision interface coupling system are investigated.The effects of the control and interface parameters on the system's stability are analyzed.The frequency range of self-excited vibrations is investigated from the energy point of view.The phenomenon of self-excited vibrations is elaborated with the phase trajectory.The corresponding control strategies are briefly analyzed with respect to the vibration mechanism.The results show that when the levitation objects collide with the mechanical interface,the system's vibration frequency becomes larger with the decrease in the collision gap;when the vibration frequency exceeds the critical frequency,the electromagnetic system continues to provide energy to the system,and the collision interface continuously dissipates energy so that the system enters the self-excited vibration state.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.YX2010-20)the National Natural Science Foundation of China(No.31570708,No.30901162)the Open Projects Foundation of Key Laboratory of Soil and Water Conservation&Desertification Combat(Beijing Forestry University),Ministry of Education of China(No.201002)
文摘Roots play an important role in stabilizing and strengthening soil. This article aims to study the mechanical properties of the interface between soil and roots with branches, using the pullout test method in the laboratory. The mechanical properties of the soil-root with branches interface is determined through the pullout-force and root-slippage curve （F-S curve）. The results of investigating 24 Pinus tabulaeformis single roots and 55 P. tabulaeformis roots with branches demonstrated three kinds of pullout test failures： breakage failure on branching root, breakage failure on branching node, and pullout failure. The branch angle had a remarkable effect on the failure mode of the roots with branches： the maximum pullout force increased with the sum of the branch diameters and the branch angle. The peak slippage and the initial force had a positive correlation with the sum of the branch diameter. The sig- nificance test of correlation between branch angle and the initial force, however, showed they had no correlation. Branch angle and branch root diameter affect the anchorage properties between root system and soil. Therefore, it is important to investigate the anchorage mechanics of the roots with branches to understand the mechanism of root reinforcement and anchorage.
基金supported by the National Natural Science Foundation of China (No.41772313)the National Natural Science Foundation for Young Scientists of China (No.52104111)+3 种基金the Hunan Science and Technology Planning Project,China (No.2019RS3001)the Natural Science Foundation of Hunan Province,China (No.2021JJ30819)Key Science and Technology Project of Guangxi Transportation Industry (Research on fine blasting and disaster control technology of mountain expressway tunnel),Chinathe financial contribution and convey their appreciation for supporting this basic research。
文摘To investigate the dynamic behavior and energy dissipation of the rock−concrete interface,dynamic splitting tests on bi-material discs were conducted by using the split Hopkinson pressure bar.The test results reveal that with the change of the interface inclination angles(θ),the influence of interface groove width on the bearing capacity of specimens also varies.Whenθincreases from 0°to 30°,the bearing capacity of the specimen increases first and then decreases with the rise of the interface groove width;the optimal groove width on the rock surface in this range of interface inclination angles is 5 mm.Whenθincreases from 45°to 90°,the bearing capacity of the specimen has no obvious change.Moreover,whenθincreases from 0°to 45°,the dissipated energy of the specimens rises obviously at first and then tends to be stable as the width of the interface groove increases.
基金financially supported by the National Natural Science Foundation of China(U 1507123)the Foundation from Qinghai Science and Technology Department(2014-HZ-817)Kunlun Scholar Award Program of Qinghai Province
文摘Calcium sulfate whiskers（CSWs） modified with glutaraldehyde-crosslinked poly（vinyl alcohol）（PVA） or traditional surface modifiers,including silane coupling agent,titanate coupling agent and stearic acid,were used to strengthen poly（vinyl chloride）（PVC）,and the morphologies,mechanical and heat resistant properties of the resulting composites were compared.The results clearly show that glutaraldehyde cross-linked PVA modified CSW/PVC composite（c PVA@CSW/PVC） has the strongest interfacial interaction,good and stable mechanical and heat resistant properties.Nielsen＇s modified Kerner＇s equation for Young＇s modulus is better than other models examined for the CSW/PVC composites.The half debonding angle θ of c PVA@CSW/PVC composite is lower than that of other composites except silane coupling agent modified CSW/PVC composites,indicating a very strong interfacial adhesion between c PVA@CSW and PVC.In general,cross-linked PVA is effective and environmentally friendly in modifying inorganic fillers.
基金funded by China Scholarship Council (No. 201406460053)
文摘In this work, low-carbon steel specimens were subjected to the quenching and partitioning process after being partially or fully austenitized to investigate their microstructural evolution and mechanical properties. According to the results of scanning electron microscopy and transmission electron microscopy observations, X-ray diffraction analysis, and tensile tests, upper bainite or tempered martensite appears successively in the microstructure with increasing austenitization temperature or increasing partitioning time. In the partially austenitized specimens, the retained austenite grains are carbon-enriched twice during the heat treatment, which can significantly stabilize the phases at room temperature. Furthermore, after partial austenitization, the specimen exhibits excellent elongation, with a maximum elongation of 37.1%. By contrast, after full austenitization, the specimens exhibit good ultimate tensile strength and high yield strength. In the case of a specimen with a yield strength of 969 MPa, the maximum value of the ultimate tensile strength reaches 1222 MPa. During the partitioning process, carbon partitioning and carbon homogenization within austenite affect interface migration. In addition, the volume fraction and grain size of retained austenite observed in the final microstructure will also be affected.
基金funding support from National Natural Science Foundation of China(Grant No.41831278).
文摘For a special geological structure of columnar jointed rock mass(CJRM),its mechanical properties are strongly affected by the columnar joints.To describe the fracture behaviors of CJRM using the basic theories of interface mechanics for composite materials,the interface stresses of the vertical and horizontal joints,which are the two primary joints in the CJRM under triaxial compression,are studied,and their mathematical expressions are derived based on the superposition principle.Based on the obtained interface stresses of the vertical and horizontal joints in the CJRM,the crack initiation of the joint interface in the CJRM is studied using the maximum circumferential stress theory in fracture mechanics.Moreover,based on this investigation,the fracture behaviors of CJRM are analyzed.According to the results of similar material physical model tests for the CJRM,the theoretical study is verified.Finally,the influence of the mechanical parameters of the CJRM on the joint interface stress is discussed comprehensively.
基金financially supported by the National Natural Science Foundation of China (No.51271017)the Fundamental Research Funds for the Central Universities (No.FRFTP-13-033A)the Program for New Century Excellent Talents in University (No.NCET-10-0227)
文摘Diamond particles reinforced aluminum–silicon matrix composites,abbreviated as Al（Si）/diamond composites,were fabricated by squeeze casting.The effect of Si content on the microstructure and mechanical properties of the composites were investigated.The mechanical properties are found to increase monotonically with Si content increasing up to 7.0 wt%.The Al-7.0 wt% Si/diamond composite exhibits tensile strength of 78 MPa,bending strength of 230 MPa,and compressive strength of426 MPa.Al–Si eutectic phases are shown to connect with Al matrix and diamond particles tightly,which is responsible for the enhancement of mechanical properties in the Al（Si）/diamond composites.
基金financially supported by the National Natural Science Foundation of China (No.50875005)Beijing Natural Science Foundation (No.3102005)
文摘Laser fusion brazing welding was proposed.Galvanized steel/AA6061 lapped joint was obtained by laser fusion brazing welding technique using the laser-induced aluminium molten pool spreading and wetting the solid steel surface.Wide joint interface was formed using the rectangular laser beam coupled with the synchronous powder feeding.The result showed that the tiny structure with the composition of a-Al and Al–Si eutectic was formed in the weld close to the Al side.And close to the steel side,a layer of compact Fe–Al–Si intermetallics,including the Al-rich FeAl3,Fe2Al5 phases and Al–Fe–Si s1 phase,was generated with the thickness of about 10–20 lm.Transverse tensile shows the brittlefractured characteristic along to the seam/steel interface with the maximum yield strength of 152.5 MPa due to the existence of hardening phases s1 and Al–Fe intermetallics.
基金Item Sponsored by National Basic Research Program of China(2010CB630801)
文摘The deformation and micro-voids formation mechanisms in ferrite / bainite（ F / B） multi-phase steel with the volume fraction of bainite less than 50% were studied by numerical simulation and experimental observation. The results show that the micro-strain concentrates at the soft / hard phase（ F / B） interface in the multi-phase steel,which should be correlated with the mechanism of incoordinate deformation. During the necking of the steel,the micro-voids initially form around the F / B interface,which also form in ferrite and bainite with the severe strain. The micro-voids in bainite are more dense and finer than those in ferrite. The failure mechanism of bainite is the coalescence of micro-voids,and the failure mechanism of ferrite is the growth and tearing of micro-voids. Due to the different failure mechanisms of ferrite and bainite,a suitable part of soft phase would be beneficial to the capability of anti-failure of F / B multi-phase steel during the ductile fracture.
基金supported by the National Natural Science Foundation of China(52005361)the Central Science and Technology Research Fund(YDZJSX2022A022)+3 种基金the Postdoctoral Science Foundation of China(2021M692373)the State Key Laboratory of Material Processing and Mold Technology of Huazhong University of Science and Technology(P2022-004)the China Postdoctoral Science Foundation Project(2023T160474)Open Research Fund from the Hai'an&Taiyuan University of Technology Advanced Manufacturing and Intelligent Equipment Industrial Research Institute(2023HA-TYUTKFYF019).
文摘Based on the two-pass differential temperature rolling bonding method,the effects of prefabricated steel/aluminum composite panel temperature on interface characteristics and microstructure properties were investigated through experimental analysis and finite element simulations.When the temperature exceeds 400℃,the effective preparation of the steel-aluminum transition joint can be achieved,and with the increase in temperature,the interface shear and pull-off strength of the steel-aluminum transition joint exhibits an initial decrease followed by an increase.Both the interface shear and pull-off fractures are in 1060 aluminum matrix.As the temperature increases,the size of the average grain in 1060 aluminum matrix increases and then decreases.When the temperature reaches 550℃,the comprehensive performance of the prepared steel-aluminum transition joint is the best,with the interface shear strength of 77 MPa and the interface pull-off strength of 153 MPa,exceeding the bonding strength of the explosive compounding method.There are no pinholes,wrinkles,or cracks in the lateral bending matrix and the interface.
