Papers by Keyword: Contact Element

Abstract: The mechanical analysis of sliding frictional contact under small scales is important to improve the understanding about the influence of the contact conditions on the real contact area and, consequently, on the apparent coefficient of friction. This study uses the finite element method to model the contact between an elastoplastic body and a rigid surface with a unidirectional sinusoidal topography, including large sliding. A sensitivity analysis is presented, studying the influence of the initial average pressure, local coefficient of friction and asperity wavelength on the contact conditions. The ratio between total tangential and normal force (apparent friction coefficient) reaches a steady state after a sliding distance of five roughness wavelengths, except for lower values of average initial contact pressure. Increasing the initial average contact pressure leads to an increase of the steady state apparent friction coefficient, particularly for a surface with sharper asperities. This increasing tends to stagnate also with the increase of the local friction coefficient. Withing the cases studied, increasing the initial average contact pressure from 25% to 100% of the material yield stress, leads to an increase of up to 0.07 in the apparent coefficient of friction and of the real-to-apparent contact area ratio up to 30%.

Abstract: The contact finite element method is proposed to analyze the stress and deformation distribution of elastic expansion sleeve in the paper. The maximum stress position of each component under the most dangerous working condition is obtained. The effect of structure dimension on stress and deformation of elastic expansion sleeve is found out. The structure dimension meeting the practical requirements is gotten. The analysis results provide the reliable theory basis for the design. The optimization for the structure and processing technology of elastic expansion sleeve is realized, based on simulating the design structure.

Abstract: Here computational models of contact of elastic systems with the contact finite elements (CFE) in a 2D or 3D frame-rod systems are reviewed. The solution is based on the method of the step-by-step analysis taking into account the character of loading, the complicated conditions of the contact and other factors consideration of which approaches the calculation circuit of the task to the real operating conditions of any structures or construction

Abstract: Gravity platform was widely used in the development of marginal oil field, but the existence of scour pit caused by the flow and wave increasing the possibility to overturn. The paper introduced the no depth contact interface element to simulate the nonlinear effect between the bucket skirt and soil, and introduced the birth-death element to simulate the increasing scour pit. The results provide guidance to prevent overturning.

Abstract: Here computational models of contact of elastic systems with the contact finite elements (CFE) in a 2D or 3D frame-rod systems are reviewed. The solution is based on the method of the step-by-step analysis taking into account the character of loading, the complicated conditions of the contact and other factors consideration of which approaches the calculation circuit of the task to the real operating conditions of any structures or construction

Abstract: The weak formulation of the Lagrangian control equations considering the contact constraint conditions and the FEM discrete equations have been derived. The non-linear and non-smooth problems of the mechanical response are solved perfectly by adopting the suggestion method for which tolerance large tangential slipping of the contact surface. One excavation bedding rock slope of the Hu-Rong-Xi expressway is analyzed applying the method mentioned above. The distribution rules of the displacement, stress, strain, contact state, contact friction force and sliding distance under the status of critical sliding are obtained. The analysis results indicate that the failure of the bedding slope is a progressive course. The interlayer stagger firstly, then the deformation evaluates to creep bedding slip and the bottom rock occurs buckling slip at last. The destruction model changes form the bedding slide to rock buckling slip.

Abstract: Based on the kinematics optimization method integrated in ADAMS, the mechanism parameters of the loader boom for a wheel loader are designed to keep the variety of the pylon rotation angle as smaller as possible during the loader boom lifting or falling process. A rigid-flexible coupled model is developed to analyze the dynamic stress of the lift arm and the contact element methodology is adopted to model the coaxial rotary joints connections. The results simulated by ADAMS indicate that the optimization is well fulfilled. Integrated kinematics optimization and strength analysis provide the well basis for further optimization of whole structure.

Abstract: In order to determine interlayer separation threshold and separation stability of complex roof, distribution of interlayer separation was analyzed in different conditions by a contact element method based on nonlinear contact theory in ANSYS program. The conclusion was drawn that normal stress was tension stress in the center of construction surface in deep mining and it could be considered as interlayer separation threshold of complex roof.

Abstract: We established a calculation model for retaining structures with double-row piles by using the midas GTS finite-element software, considering the interaction between pile and soil and adopting the contact element method, on the basis of a practical engineering application. We then determined a reasonable elastic modulus of reinforced soil bodies, thereby enabling the study of the influences of the reinforcement depth and width in the interpile soil on the internal force and displacement of the retaining structure with double-row piles. We present suggestions for reinforcement depth and width. The study results provide valuable reference for engineering design, construction, and cost control.

Abstract: Concrete-filled steel tubular(CFT) columns are often used as the main supporting columns for high-rise buildings and has become a topic of academic concern. The past research about CFT most focused on its ultimate strength and mechanical behavior. The experiment method which is usually expensive and time-consuming. Other research methods include combining experimental data with appropriate theory to design or calculate the structural properties, and these methods tend to have a conservative assessment of the results. Therefore, some researches have been developing finite element model to simulate and analyze the ultimate strength and buckling condition of CFT and its component behavior. In this paper, finite element analysis is used to explore the mechanical behavior of CFT during exerting axial compression load. Contact pair settings and friction coefficient settings were compared with different pattern to investigate the accuracy of simulation and the mechanical behavior of CFT columns. Study found that the ultimate strength for CFT columns obtained by finite element analysis can achieve good accuracy, and in the mean time the mechanical behavior simulation of CFT columns with proper finite element settings could be achieved.