锻压技术

基于滑移约束面方法的毛坯反求技术

英文标题：Blank design of sheet metal forming based on sliding constraint surfaces methodology

作者：谢慧超廖代辉龚英菊

单位：湖南大学汽车车身先进设计制造国家重点实验室湖南大学汽车车身先进设计制造国家重点实验室重庆警官职业学院交通工程系湖南长沙410082 湖南交通职业技术学院机电工程系湖南长沙410082 湖南长沙410082 重庆400039

分类号：TG386

出版年,卷(期):页码：2008,33(2):134-137

摘要：

由于一步逆算法在用于求解坯料展开问题中,并不能得到足够准确的毛坯,其计算误差会随着变形路径的复杂程度而变大。本文提出采用多步逆算法得到较为精确的毛坯形状及应力、应变分布。多步逆算法将成形过程分成几个工步进行模拟,并通过引入滑移约束面得到中间成形形状,采用牛顿-拉费森迭代将材料坐标和全局坐标中的残余应力转换到局部坐标。将此算法应用于油底壳的拉深计算,通过对比计算结果与实验结果,两步法得到的毛坯右端与实验结果十分吻合。多步有限元逆算法进一步提高了毛坯展开尺寸及应力分布的计算精度。

Accurate blank shape can not be obtained by one-step finite element inverse analysis as the computation error would increase along with the complexity of deformed path.A multi-step finite element inverse analysis method was presented to obtain more accurate shape of blank and stress/strain distribution.The forming was distributed into several processes by the new method.The sliding constraint surfaces were introduced to calculate the intermediate shape of forming.The N-R iteration was introduced to transform the residual stress in material coordinates and global coordinates to local coordinates.The presented algorithm was applied to an oil-pan drawing.The numerical results confirm the validity and versatility of the algorithm with the initial blank shapes calculated and comparison to experimental results. The accuracy of computation was improved by the new method.

基金项目：

国家自然科学基金(2002002);; 湖南省科技厅科研基金(2004339386);; “十一五”国家科技支撑计划(2006BAF02A02-03)

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