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contact DEFORMATION AND PRE-CONTROL OF TRANSMISSION PROPERTIES OF POINT CONJUGATE GEAR

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Chinese Journal of Mechanical Engineering 2000年第1期13卷 76-80页

作者： Liu Huran Yuan Wenhui (Department of Mechanical Engineering, Changsha Railway Institute) Li Rongbin (The Hong Kong Polytechnic University) 长沙铁道学院湖南长沙香港理工大学香港

According to spatial conjugate principle and theory of elastic contact, a method to pre-control transmission properties and contact mark of point meshing gear is presented, while the deformation of tooth surface is un... 详细信息

关键词： elastic contact Deformation Meshing Gear

The influence of jaw's curvature on the results of the Brazilian disc test

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Journal of Rock Mechanics and Geotechnical Engineering 2016年第2期8卷 127-146页

作者： Ch.F.Markides S.K.Kourkoulis Department of Mechanics School of Applied Mathematical and Physical SciencesNational Technical University of Athens

The general contact problem of a disc squeezed between jaws of arbitrary curvature is considered employing Muskhelishvili’s complex *** advantage of the general solution introduced,the closed-form expressions for the stresses along strategic loci(loaded rim,loaded diameter,disc’s center)are obtained,in terms of the ratio r of the disc’s to the jaw’s ***,the effect of r(as well as that of the relative stiffness of the disc’s and jaw’s materials dictating the contact arc)on the stress distribution along these loci is *** is concluded that,for both smooth contact(zero friction)and contact with friction,the role of the jaw’s curvature is significant not only along the disc-jaw contact arc(as it could be expected),but also all along the loaded *** the other hand,it is indicated that the stress field at the disc’s center is more or less insensitive to the jaw’s curvature assuming that r lies within the range(0,0.67)or in other words within the limits defined by the two standardized suggestions,*** of American Society for Testing and Materials(ASTM)(plane loading platens with r ? 0)and that of International Society for Rock Mechanics(ISRM)(curved jaws with r ? 0.67).The upper limit of this range is a kind of compromise between the need to make the stress field at the disc’s center independent of the boundary conditions while keeping at the same time the contact angle large enough to reduce the stress concentration and the risk for premature fracture initiation far from the disc’s *** jaws with radius of curvature exceeded by that suggested by ISRM,the stress field at the disc’s center is significantly *** for jaws with radius approaching that of the disc,the stress field at the disc’s center is dramatically distorted rendering Hondros’ formula inapplicable and the test results erroneous.

关键词： Brazilian disc test elastic contact Complex potentials Stress field Frictional stresses

Surrounding rock deformation analysis of underground caverns with multi-body finite element method

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Water Science and Engineering 2009年第3期2卷 71-77页

作者： Wan-jin LIANG Chao SU Fei WANG Xiao-jun TANG College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 P. R. China

Discontinuous deformation problems are common in rock engineering. Numerical analysis methods based on system models of the discrete body can better solve these problems. One of the most effective solutions is discontinuous deformation analysis （DDA） method, but the DDA method brings about rock embedding problems when it uses the strain assumption in elastic deformation and adopts virtual springs to simulate the contact problems. The multi-body finite element method （FEM） proposed in this paper can solve the problems of contact and deformation of blocks very well because it integrates the FEM and multi-body system dynamics theory. It is therefore a complete method for solving discontinuous deformation problems through balance equations of the contact surface and for simulating the displacement of whole blocks. In this study, this method was successfully used for deformation analysis of underground caverns in stratified rock. The simulation results indicate that the multi-body FEM can show contact forces and the stress states on contact surfaces better than DDA, and that the results calculated with the multi-body FEM are more consistent with engineering practice than those calculated with DDA method.

关键词： multi-body finite element method discontinuous deformation surrounding rockdeformation elastic contact coordination displacement