半圆筋循环载荷作用下的板材变形特征研究  

Study of sheet deformation characteristics under the cyclic loading applied by semi-circle drawbead

作　　者：李群[1] 李娜[1] 郭宝峰[1] 金淼[1] 

机构地区：[1]燕山大学先进锻压成形技术与科学教育部重点实验室,河北秦皇岛066004

出　　处：《锻压技术》2013年第2期31-33,共3页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(50305031);河北省自然科学基金资助项目(E2008000824);河北省科技计划项目(12217621)

摘　　要：针对板材在半圆筋中的变形具有弯曲、卸载及反向弯曲的循环加载特征,采用基于Mises屈服条件的各向同性硬化模型,对板材通过半圆筋的变形过程进行了有限元数值模拟分析,获得了板材节点通过半圆筋时沿流动方向的应力应变时间历程关系曲线。分析结果显示,板材通过半圆筋时经历了两次弯曲、卸载与反向弯曲的循环塑性变形的过程,循环加载共计经历4个加载分支。循环加载曲线在不同加载分支的应力应变关系可以近似为线性硬化,随循环加载次数增加,反映不同加载分支硬化情况的切线模量降低,并且在二次反弯曲阶段基本上不硬化。As for the cyclic loading characteristics of bending, unloading and reverse bending in the process of sheet deformation in semi-circle draw bead, with the model of isotropic hardening rule based on Mises yield criterion, the process of sheet deformation when flowing along semi-circle draw bead was analyzed by finite element analysis and the history stress-strain curves of sheet nodes along the flowing direction were gained. The results show that sheet undergoes the plastic deformation processes of bending, unloading and reverse bending twice, and the cyclic loading has four loading branches in total. The relationship between stress and strain of cyclic loading curve in different branches can be approximately considered as a linear hardening. With the increase of the number of cyclic loading, the tangent modulus indicating the hardening in different loading branches decreases, and hardening would not happen in the process of the second reverse bending.

关 键 词：板材成形 循环载荷 半圆筋 各向同性硬化 加载分支 切线模量 

分 类 号：TG386.1[金属学及工艺—金属压力加工]