六面体单元在压印成形模拟中的应用

摘要

In order to overcome the hourglass problems of the one-point integrated element used in the dynamic explicit coining simulation system COINFORM,a new multi-point integrated 8-node hexahedral element was proposed herein.The generation mechanism of volume locking and shear loc-king was deduced.With the assumed strain method,the volumetric locking in near-incompressible de-formations and the shear locking in bending situations were avoided.Combined with COINFORM,the proposed hexahedral element was applied to the coining simulation of a Ag999 commemorative coin. The results show that the locking phenomena of the multi-point integrated element are successfully a-voided in the coining simulation,and the proposed element achieves higher computational accuracy than that of the existing element of COINFORM.%针对动力显式压印成形模拟系统COINFORM中单点积分单元的沙漏问题,建立了一种采用多点积分方案的八节点六面体单元.推导了体积闭锁和剪切闭锁的产生机理,采用假设应变法,成功消除了单元在近似不可压缩变形中的体积闭锁和弯曲变形中的剪切闭锁.将建立的六面体单元与COINFORM相结合,对银999纪念币压印成形模拟算例进行了分析.研究结果表明,提出的多点积分六面体单元在压印模拟中不存在闭锁现象,且比COINFORM原有单元具有更高的计算精度.