Releasing algorithm for volume locking

 in rigid-plastic meshless method

Zhao Guoqun  Wu Xin  Wang Weidong

(Engineering Research Center of Mould & Die Technology, Shandong University, Jinan 250061)

Abstract: The meshless Galerkin method is introduced to the analysis of the metal forming processes. The fundamental theories and basic equations for the rigid-plastic meshless method are developed. The releasing of the volume locking encountered in the analysis of the metal plastic forming problems is studied and a releasing algorithm is established by modifying the volumetric strain rate in the functional equation. The volumetric strain rate calculated according to velocity field is mapped onto a lower-order space to reduce the number of independent discrete constraint equations. The algorithm can release the volumetric locking without the expense of employing large support size in the rigid-plastic meshless method. A typical metal forming problem is analyzed. The results show that the algorithm can effectively release the volumetric locking problem.

Key words: Meshless method  Volume locking  Releasing  Rigid-plastic materials  Metal forming

CLC No: TG316

教育部跨世纪优秀人才计划基金和国家杰出青年科学基金(50425517)资助项目 . Received 20050603, received in revised form 20051229