Research And Application Analysis Of Meshless Method To Elasto-Plastic Problems

The meshless method being presently developed, which based on the point approximation, would entirely or partially eliminate the mesh; it is the hot point and recent trend in the study of engineering calculation.Many domestic and international scholars carry on substantial research on meshless method, apply them to relevant fields and have gained many productions, most of which are about elastic problems. In fact, there are few ideal elastic problems in the engineering field. Generally, plastic analysis would make many projects more reasonable, and would fully utilize intensity potentiality of structures. So it has practical significance using meshless method to solve plastic problem.In this paper, the development, the application situation, the strength and the weakness of meshless method are systematically introduced; among various meshless methods,the basic theory and equation deduction of EFGM(Element Free Galerkin Method) that based on the Moving least square are emphatically introduced.Based on the comprehension of elasto-plastic mechanics, the 2D computer program of EFGM to solve elasto-plastic mechanics problems is developed according to the theory introduced to solve elasto-plastic mechanics problems by EFGM in the paper; the feasibility, correction and high accuracy of the theory and program is proved by comparing the results of several typical examples with results of ANSYS.In the paper, to elassto-plastic EFGM, some influences on computation precision are studied, such as: weight function, radical function, distribution of nodes, the size of influence domain and alteration of increment etc., based on the study, some suggestion are advanced to gain better accuracy; the modified Newton-Raphson method is adopted in the paper to solve elsto-plastic problems, effectively reducing the workload andguarantying the high precision and fast convergence; to the object that can not be compressed, the calculation result of using elasto-plastic EFGM prove that this method could avoid volume closure phenomena.In this paper, the elasto-plastic EFGM is also extended to be used in the rock, soil and concrete materials of structural engineering, the calculation results comparison of typical example under different yield criterion proved that it is absolutely feasible to apply elasto-plastic EFGM to solving heterogeneous materials.