摘要
从控制塑性变形能的角度出发,基于总塑性功的积分形式,建立板料的成形极限预测判据。这种板料成形极限预测判据考虑应变路径变化、材料的硬化指数、各向异性系数及材料的初始厚度等对成形极限的影响。判据中的参数可由常用的单向拉伸极限应变试验确定。由此通过数值模拟可以预测板料在各种不同应变路径下的成形极限,适用于成形极限图的拉—压和拉—拉应变区,从而建立完整的成形极限曲线,可大大减少试验工作量。试验验证表明,这种成形极限预测判据对于钢板和铝合金板的成形极限可做出较为准确的预测。实现了只进行单拉试验即可预测板料在不同应变路径下的成形极限。
Sheet metal forming limit prediction criterion based on general plastic work is brought out. The integral value of the general plastic work criterion is not a constant but a function relevant to strain paths. The effect of strain path, strain-hardening exponent, anisotropy coefficient and the initial thickness of the material on forming limit is considered. The constant in the criterion can be determined by the forming limit strains under tensile strain path. Then the limit strains under other strain paths between uniaxial tension to equi-biaxial tension can be determined by the criterion combined with numerical simulation of forming process. The calculation as well as the experimental results show that the criterion can predict forming limits for steel and aluminum sheets exactly and makes it possible to determine forming limit strains under defferent strain paths only through tensile test.
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2009年第4期64-69,共6页
Journal of Mechanical Engineering
基金
高等学校博士学科点专项科研基金资助项目(20040006022)。
关键词
板料冲压
成形极限
塑性变形能
数值模拟
Sheet metal forming Forming limit Plastic deformation energy Numerical simulation
