Analysis Of Mechanical Response Research Articles

Numerical simulation of mechanical response analysis of asphalt pavement under dynamic loads with non-uniform tire-pavement contact stresses

The selection of accurate input design parameters is important for understanding the dynamic response of an asphalt pavement structure. The transverse and longitudinal shear stresses that affect the dynamic response of asphalt pavement are not considered in traditional asphalt pavement design. To this end, this study utilizes the finite element method (FEM) to analyze the mechanical response of asphalt pavement under dynamic loads with non-uniform tire-pavement contact stresses. For this purpose, firstly a three-dimensional (3D) finite element (FE) model of a rubber tire is developed. Secondly, the predicted and laboratory measured stresses are compared to develop a 3D FE model of the contact stresses. Finally, a 3D FE model of the tire–pavement contact is analyzed to investigate the influence of shear stresses on the response of the asphalt pavement and the superposition effect of the mechanical response. The results show that the distribution and magnitude of the vertical contact pressure under the free-rolling state are the same as those under the static state, and the traction and braking conditions could change the symmetry of tire-pavement interactions. In addition, the shear stress at the tire-pavement interface affects the peak response of the surface layer, indicating that shear stress plays a considerable role in controlling the development of rutting and longitudinal cracks. Considering the viscoelasticity of the asphalt material, it is observed that the superposition effect of the mechanical response is a comprehensive result of the space–time domains. In conclusion, this study analyzes the influence of tire-pavement contact on the mechanical response of asphalt pavement and proposes input design parameters for improving the design of asphalt pavement.

Mechanical Response Analysis of Asphalt Pavement Structure with Embedded Sensor

Long-term and real-time monitoring of asphalt pavement can be carried out by using embedded sensors to perceive and predict structural damage during pavement operation period, so as to avoid sustained development of damage. However, the influence of embedded sensors on the mechanical properties of asphalt pavement structure and the structural optimization of sensing elements needs to be further studied. Based on the finite element numerical simulation method, static load model and three-point bending test mode were conducted with three “pavement-sensor” coupling model without sensor, with embedded I-shape sensor, with embedded corrugated-shape sensor. Three simulated conditions were studied comparatively of the sensing element embedding effect on the mechanical response of asphalt pavement structure. Results show that the sensing elements embedded with the two structures have a certain influence on the stress and strain field of asphalt concrete. Within the range of 60–100 mm the asphalt mixture is in a state of tension; the stress values increase with depth and show a maximum tensile stress state at the bottom of the beam. In the compression zone, the strain of the I-shape sensing element embedded is closer to that of the strain without the sensing element embedded. Along the axis of the two sensing elements, the axial strain of the I-shape sensing element is smoother and uniform, which ensures the deformation coordination in the road state. The optimal length L of the sensing element is 14 cm, the diameter φ of the sensor is 10 mm, and the I-beam length GL is 10 cm.

Nonlinear dynamic mechanical response analysis of dual-segment single-span rotor-bearing system under normal condition and misalignment fault

Nonlinear dynamic mechanical response analysis of dual-segment single-span rotor-bearing system under normal condition and misalignment fault

Progressive Damage Behaviour Analysis and Comparison with 2D/3D Hashin Failure Models on Carbon Fibre-Reinforced Aluminium Laminates.

It is known that carbon fibre–reinforced aluminium laminate is the third generation of fibre metal materials. This study investigates the response of carbon fibre–reinforced aluminium laminates (CARALL) under tensile loading and three-point bending tests, which evaluate the damage initiation and propagation mechanism. The 2D Hashin and 3D Hashin VUMAT models are used to analyse and compare each composite layer for finite element modelling. A bilinear cohesive contact model is modelled for the interface failure, and the Johnson cook model describes the aluminium layer. The mechanical response and failure analysis of CARALL were evaluated using load versus deflection curves, and the scanning electron microscope was adopted. The results revealed that the failure modes of CARALL were mainly observed in the aluminium layer fracture, fibre pull-out, fracture, and matrix tensile fracture under tensile and flexural loading conditions. The 2D Hashin and 3D Hashin models were similar in predicting tensile properties, flexural properties, mechanical response before peak load points, and final failure modes. It is highlighted that the 3D Hashin model can accurately reveal the failure mechanism and failure propagation mechanism of CARALL.

A comprehensive mechanical response and dynamic stability analysis of elastically restrained bi-directional functionally graded porous microbeams in the thermal environment via mixed finite elements

A comprehensive mechanical response and dynamic stability analysis of elastically restrained bi-directional functionally graded porous microbeams in the thermal environment via mixed finite elements

Structural dimension optimization and mechanical response analysis of fabricated honeycomb plastic pavement slab

Structural dimension optimization and mechanical response analysis of fabricated honeycomb plastic pavement slab

Thermal Induced Interface Mechanical Response Analysis of SMT Lead-Free Solder Joint and Its Adaptive Optimization.

Surface mount technology (SMT) plays an important role in integrated circuits, but due to thermal stress alternation caused by temperature cycling, it tends to have thermo-mechanical reliability problems. At the same time, considering the environmental and health problems of lead (Pb)-based solders, the electronics industry has turned to lead-free solders, such as ternary alloy Sn-3Ag-0.5Cu (SAC305). As lead-free solders exhibit visco-plastic mechanical properties significantly affected by temperature, their thermo-mechanical reliability has received considerable attention. In this study, the interface delamination of an SMT solder joint using a SAC305 alloy under temperature cycling has been analyzed by the nonlinear finite element method. The results indicate that the highest contact pressure at the four corners of the termination/solder horizontal interface means that delamination is most likely to occur, followed by the y-direction side region of the solder/land interface and the top arc region of the termination/solder vertical interface. It should be noted that in order to keep the shape of the solder joint in the finite element model consistent with the actual situation after the reflow process, a minimum energy-based morphology evolution method has been incorporated into the established finite element model. Eventually, an Improved Efficient Global Optimization (IEGO) method was used to optimize the geometry of the SMT solder joint in order to reduce the contact pressure at critical points and critical regions. The optimization result shows that the contact pressure at the critical points and at the critical regions decreases significantly, which also means that the probability of thermal-induced delamination decreases.

Analysis of mechanical response and energy efficiency of a pavement integrated photovoltaic/thermal system (PIPVT)

Photovoltaic pavement technology was introduced several years ago but has not yet reached commercial maturity, and there are still many technical difficulties to be overcome, such as heat dissipation issues. Using PV cells to generate sufficient energy requires high solar insolation, but high temperatures will also reduce its efficiency.Therefore, this research evaluates the potential of a pavement integrated PV/T system (PIPVT), which incorporates photovoltaic/thermal (PV/T) technology into the roads for power and thermal energy harvesting. While solving the heat dissipation problem of the PV pavement, it can also recover the heat that cannot be used by the PV cells. A unit block of hollow structure 3D printed using plastic material with tempered glass as a protective layer and ABS plastic was used in this paper. A 3D computational finite element model (FEM) developed in ABAQUS was used to analyse the mechanical response of the structure, and a laboratory experiment was conducted to test the influence of the heat dissipation method incorporating water filled pipes on the power generation efficiency of PV cells. The results show that the introduced water circulating pipes had a negligible effect on the mechanical response of PV pavement unit blocks; PIPVT can significantly reduce the solar panel's temperature, and the temperature drop can be as high as 22 °C. According to the results, the primary energy-saving efficiency of PIPVT is estimated to be almost twice that of the conventional PV module. Therefore, this study showed the PIPVT had benefits that went far beyond solar energy generation.

Research on Mechanical Response of Polymer Grouting Repair for Longitudinal Cracks in Reconstructed and Expanded Expressway Pavement

Polymer grouting materials have been widely used in road repair projects. In order to study the application of polymer grouting materials in repairing the joint cracks and voids of new and old subgrades in the reconstruction and expansion projects of expressways. According to the phenomenon investigation data, ABAQUS finite element software was used to establish a three-dimensional road mechanical response analysis model, and the mechanical response characteristics of the road before and after polymer grouting were systematically analyzed. The research results of the road which was repaired by polymer grouting show that the shear force between the polymer grouting material and the materials on both sides of the old and new subgrades can repair the cracks at the joint and the diseases in the void area of the new subgrade, so as to reduce the displacement and settlement of the road surface. The maximum dynamic stress peak value of the old and new subgrade road surfaces is located at the load action position, and with the increase of the distance from the load action position, the dynamic stress peak value gradually decreases, showing an M-shaped distribution as a whole. The original stress transfer law of the road structure was changed, so that the dynamic stress of the new subgrade is significantly smaller than that of the old subgrade. The critical surface formed between polymer grouting material and subgrade material has a certain shear strength, which reduces the tensile stress and strain between structural layers. It will improve the bearing capacity of the subgrade and at the same time provide a practical reference for the treatment of longitudinal cracks in the reconstruction and expansion of expressway.

Micromechanical analysis of the rutting evolution of asphalt pavement under temperature–stress coupling based on the discrete element method

The macrorutting phenomenon of asphalt pavement is intrinsically related to the micromechanical characteristics of asphalt mixtures. In addition, changes in temperature and the repeated action of vehicles keep the pavement in a complex service state. Based on the discrete element method, this paper conducted a virtual rutting test of Hamburg pavement to capture the micromechanical evolution mechanism of rutting under complex temperature–stress coupling. Burgers and linear constitutive models were adopted to describe the viscoelastic and linear properties of mastic and aggregates, respectively. The transformation relationships between macro- and microparameters were deduced based on mechanical theory, and the macroparameters at different temperatures were determined through a creep test. To improve the calculation efficiency, the static load equivalent and time temperature equivalent principles were adopted to simulate pavement rutting, which was verified by laboratory rutting tests. In addition, the movements of coarse aggregates and the contact forces within the mixture were statistically analyzed under different loading times, temperatures and tire pressures. The results showed that the virtual rutting test can accurately predict the permanent deformation of pavement under a complex temperature–stress coupling field. The mechanical response analysis demonstrated the load distribution and transfer mechanism within the pavement and clearly explained the evolution process of rutting from the perspective of micromechanical views. Moreover, the influence law of parameters on rutting performance was illustrated using micro discrete mechanical theory.

Mechanical Response Analysis of Asphalt Pavement Based on the Interlayer Contact State between Cement-stabilized Magnesium Slag–Aeolian Sand Base

Mechanical Response Analysis of Asphalt Pavement Based on the Interlayer Contact State between Cement-stabilized Magnesium Slag–Aeolian Sand Base

颗粒形状对隧道开挖砂性地层稳定性影响的力学响应分析

颗粒形状对隧道开挖砂性地层稳定性影响的力学响应分析

Special issue of Engineering Analysis with Boundary Elements: Computational approaches to mechanical response analysis of structures at diverse scales

Special issue of Engineering Analysis with Boundary Elements: Computational approaches to mechanical response analysis of structures at diverse scales

Mechanical Response Analysis of Battery Modules Under Mechanical Load: Experimental Investigation and Simulation Analysis

Lithium‐ion batteries are widely used in the automotive, military, and energy storage fields, and the crash safety of batteries has attracted widespread attention. Herein, mechanical experiments are first carried out on a battery module (consisting of 18 650 cylindrical cells connected in parallel) and its components. The loading rates of the circular plates in the experiments are 1, 5, and 10 mm min−1. Based on the experimental data, a finite‐element model of the module is developed and validated. The mechanical response of the module under static and dynamic conditions is then investigated through experiments and simulations. A parametric study is carried out to analyze the role played by the module holder in the mechanical response of the module. It is found that the presence of the module holder is effective in improving the distribution of the high‐pressure region under impact loading but causes a local increase in pressure peaks. This research work can provide a useful reference for the safe design of battery modules.

An Operating Model for an EPB Shield TBM Simulator by the Correlation Analysis of Operational Actions and Mechanical Responses

This study reports on the development of an operating model for an EPB Shield TBM simulator by the correlation between operating parameters. First, four main operating parameters required for excavation are analyzed, then multiple regression analysis estimates their requirements depending on the ground conditions and the TBM’s specifications. Further multiple regression analysis then determines the interactions between six operational actions and ten mechanical responses. Operating procedures are established, and interlock and warning alarm systems are designed for use in the operating model. Lastly, several simulations were tested for the operating model of the TBM simulator under various conditions.

Micromechanical Analysis of Mechanical Response for Unidirectional Fiber-Reinforced Plies

Micromechanical Analysis of Mechanical Response for Unidirectional Fiber-Reinforced Plies

Numerical simulation analysis of tunnel construction mechanical response considering shotcrete hardening process

At present, tunnel construction mechanics studies basically do not consider the hardening process of shotcrete. In order to reveal the hardening process of sprayed concrete in a sulfate environment and the influence of sulfate corrosion on tunnel stability, the model parameters were determined in combination with the change rules of mechanical parameters of shotcrete obtained in the author’s experiment. The MIDAS GTSNX finite element software was used to analyze the effect of the hardening process of the shotcrete, chemical corrosion, and physical corrosion of sulfate on the displacement and stress of the surrounding rock of the tunnel. The results show that considering the hardening process of shotcrete, the growth rate of tunnel clearance displacement increases, and the stress increase slows in the early stage of shotcrete (The tunnel lining structure is applied, and the second step of excavation is carried out). With the increase of time or the construction steps, the stress of shotcrete increases significantly, and the clearance displacement growth rate significantly decreased. The influence of the chemical and physical corrosion of shotcrete on the stress and displacement of the surrounding rock of the tunnel is similar to considering the hardening process of shotcrete. indicating that sulfate corrosion has an inhibitory effect on the hardening process of shotcrete and increased construction risk.

Analysis of Mechanical response of Granular Buried Ditch under high-fill foundation

High-fill foundations can solve the problem of land shortage in mountainous cities. In high ground stress and water immersion environment, stress concentration will lead to gravel particle breakage in drainage blind ditch, and the drainage blind ditch exists a risk of drainage failure, which will bring great harm to high-fill foundation. In this paper, model tests and PFC simulation were carried out to analyze the mechanical response of gravel particles in drainage blind ditch under high ground stress and water immersion. Firstly, large-scale triaxial shear tests were carried out to explore the effects of confining pressures, dry-wet conditions and initial void ratios on breakage and mechanical characteristics of gravel particles. The stress-strain curve of gravel particles was studied and the influence of variation of gravel graduation and particle crush rate on peak strength and dilatancy were analyzed. Then, the single particle breakage model under high pressure was established and the influence of immersion was considered in numerical simulation. The crushing test of gravel particles was carried out and the impact of particle breakage on mechanical characteristics was studied. The results show that the stress-strain curve of gravel particles has a behavior of strain hardening. Particle breakage has a significant impact on the strength and dilatancy of gravel particle. The gravel particle breakage rate is approximately linear with confining pressure and initial void ratio. Immersion of the gravel particle increased the volumetric strain, weakened the dilatancy and increased the gravel particle breakage rate.

EXPERIMENTAL INVESTIGATION ON THE CREEP RESPONSE AND THERMAL EXPANSION OF PARALLEL STEEL WIRES AT ELEVATED TEMPERATURES

The thermal expansion at 15 different temperatures and the high temperature creep at multiple stress levels of 1670 MPa parallel steel wires, which are widely used in practical engineering, were experimentally investigated by a charge-coupled device camera (CCDC) system. The tensile strength of the specimens which experienced 2-hour’s high temperature creep investigation was measured at the ambient temperature. The curves of thermal expansion strain and high temperature creep strain of the parallel steel wires were obtained. The test results show that the thermal expansion strain of the parallel steel wires increased nonlinearly with the increase of the temperature and the microstructure changed at 750 ℃. Both the heating temperature and the stress level significantly affected the high temperature creep strain. At a higher temperature, the effect of the stress level on the residual tensile strength of the parallel steel wires was more significant. Compared with the 1860 MPa pre-stressed twisted steel wires, the 1670 MPa parallel steel wires had a lower creep strain at a high temperature. Based on the test data, the function of the thermal expansion coefficient of parallel steel wires with respect to the temperature and the high temperature creep model are proposed. The thermal expansion coefficient and the high temperature creep model proposed in this paper can benefit the mechanical response analysis of pre-stressed steel structures at elevated temperatures.

Mechanical Response Analysis of Large Section Transverse Channel Construction in Metro Station

Mechanical Response Analysis of Large Section Transverse Channel Construction in Metro Station