机械零件损伤和断裂的分析计算与失效过程的计算机模拟

应用断裂力学的最大正应力准测，应变能释放率准则和有限元技术找出受力零件的危险点，以及零件在交变载荷作用下该点的裂纹扩展方向，在计算机上模拟出零件的损伤部位和裂纹的动态扩展过程。已计算和显示的实例有受拉伸的中心斜裂纹平板和受拉伸的边裂纹平板。还对常用的齿轮轮齿根部受弯后的疲劳裂纹、燃气涡轮盘榫齿裂纹的产生和扩展过程进行了模拟，结果与实际损坏状态基本相符。这一失效过程的计算机模拟，对机器零件的排故和改

ANALYTICAL COMPUTATION OF DAMAGES AND COMPUTER SIMULATION OF PROCESSES OF FAILURE FOR MACHINE PARTS

Maximum tangential stress criterion,energy release rate criterion,and minimum strain energy density factor criterion in fracture mechanics are made use of with the aid of a computer,in locating the dangerous point of machine elements under specific loads and the direction of propagation of fatigue crack in machine elements under repeated load. Through this the damage position and the dynamical process of the crack propagation of machine elements can be simulated with the computer by means of the finite element method (FEM). Practical examples which have been computed and displayed include the mechanical models of the cases of a centre-and edgecracked plate in tension. Crack growth and process of propagation of bending fatigue crack in gear teeth and tenon teeth of a turbine wheel have been simulated. The results are basicaly in coincidence with the actual damage situation. The computation and simulation of the damage process are meaningful in furnishing guidance toward the removal of trouble spots and toward a refined design of machine elements.