NUMERICAL SIMULATION WITH ELEMENT-FREEMETHOD BASED ON THE WAVELET BASIS FUNCTION INTHE SHEET METAL FORMING

摘要

There are severe deformation and high stress gradient field inrnthe sheet metal forming. Traditional finite element analysis ofrnsheet metal forming processes often requires not only explicitrnmesh or element shape function with high order but also thernpost-processing for the ideal precision. Because of thernelement mesh property it is difficult to get high qualityrndistributed node by the method of discrete node or refinementrnnode, and at the same time the technology of post-processingrnalso affects the computation precision. Element-free methodrnbreaks away the restriction of element mesh. Firstly, thernadaptive refinement and discretization can be easily achieved,rnso it well adapts to analyze high stress gradient; Secondly, itrnsubstitutes wavelet basis for the polynomial series which arernusually used in traditional element-free method, so it has thernexcellent property of wavelet transform, localization andrnmulti-resolution character, and can overcome thernmesh-sensitivity or the stress field discontinuity of finiternelement method. Forming processes for a square cup deeprndrawing is analyzed by this element-free method and thernresults are satisfied very well with the software DYNAFORMrnsolutions.