弹塑性力学功课(国外英文资料).docVIP

弹塑性力学作业(国外英文资料) 1.22 the task of elastic mechanics and plastic mechanics The structural design based on elastic analysis is assumed to be ideal for elasticity. Accordingly, this kind of design idea to the results of the analysis of the actual scope as the failure criterion of design, argues that the stress reaches a certain limit, will enter the stage of plastic deformation, the materials will be destruction that structural failure, as a result of the general structure is non-uniform stress state, when a high stress points or the material reaches the elastic line of high stress area, within a structure for most of the material is still in the elastic region; And the actual material does not actually occur after stress than elastic limit damage, still have a certain ability to continue to stress only relatively lower stiffness. Therefore, the flexible design method can not fully utilize the potential of the material and cause some waste of the material. In fact, when the local material entered the stage of plastic deformation inside the structure, to continue to increase outside load, the structure of the internal force distribution more uniform, the original material at low stress area under more stress, so as to better play to the potential of materials, improving the bearing capacity of the structure. Obviously, design based on plastic analysis is superior to elastic design. However, plastic design allows greater deformation structure, and completely residual deformation after unloading structure will exist, therefore, higher requirements for stiffness and residual deformation of the occasion, are not allowed to appear this kind of design method is not applicable. Also, in some cases, you need to take advantage of the global plasticity; In some cases, if you dont think about the plasticity of the material, you dont get the actual results. Material mechanics, elastic mechanics and plastic mechanics on the basic contents and methods of the study have some similarit