摘要
逆方法 (IA)是一种基于产品最终形状的,应用于构建轴对称冷锻造过程模型的简单方法。由于是假设在简单路径下变形,而且简化了工具的作用形式,因此该方法计算速度很快;数值测试显示,该种方法因为没有考虑变形历史,因而只能较好的估算应变,但是应力估算的误差较大。该文提出了一种新方法——拟逆方法 (PIA:Pseudo Inverse Approach),这种方法是在保留IA优势的基础上,考虑了工件的加载历史,因而可以较好的估算应力。PIA引入了多个中间构型来考虑变形路径,摒弃了传统的接触问题的处理方法,采用自由表面法对中间构型进行修正。另外,基于等效应力的概念和拉伸应力应变曲线,提出了一种全新的塑性积分的直接算法,并编写了快速健强的计算程序。通过和ABAQUS的计算结果的比较,研究了PIA的计算效率和局限性,结果表明,该方法可以应用于初始预成形的设计以及锻造工艺的参数优化。
A simplified method called ＂Inverse Approach＂（IA） has been developed for axi-symmetrical cold forging modelling.The approach is based on the knowledge of the final part shape.The assumptions of the proportional loading and the simplified tool actions make the Inverse Approach calculation very fast.Numerical tests have shown that the Inverse Approach gave fairly good strain estimation but poor stress estimation because of neglecting the loading history.A new approach called ＂Pseudo Inverse Approach＂（PIA） was presented which keeps the advantages of the Inverse Approach but gives good stress estimation taking into account the loading history.Some intermediate configurations were introduced and corrected by using a free surface method to consider the deformation paths without classical contact treatment.A new direct algorithm of plasticity was developed using the notion of equivalent stress and the tensile curve,leading to a very fast and robust plastic integration procedure.The comparison with ABAQUS shows the efficiency and limitations of the PIA.This PIA can be used for the preliminary preform design and optimization for the forging process modelling.
出处
《塑性工程学报》
CAS
CSCD
北大核心
2011年第6期1-14,共14页
Journal of Plasticity Engineering
基金
Acknowledgment The financial support of the French State and the Champagne-Ardenne Region is gratefully acknowl- edged.
关键词
冷锻工艺
拟逆方法
快速塑性积分直接算法
cold forging process
pseudo inverse approach
large strains direct algorithm of plasticity
