基于解耦计算的多步快速成形有限元法  

Multi-Step Quick Forming Finite Element Method Based on Decoupling Calculation

作　　者：鲍益东[1] 席洁 秦雪娇[1] 刘永财 BAO Yidong;XI Jie;QIN Xuejiao;LIU Yongcai(Nanjing University of Aeromautics and Astronautics,Nanjing 210016,China;Changzhou Institute of Technology,Changzhou 213032,China)

机构地区：[1]南京航空航天大学,南京210016 [2]常州工学院,常州213032

出　　处：《航空制造技术》2023年第9期14-22,共9页Aeronautical Manufacturing Technology

基　　金：国家自然科学基金(51975280)。

摘　　要：钣金零件是构成飞机机体和汽车车身的重要零部件。为缩短钣金件的生产周期,将有限元法用于零件设计初期评估零件的可制造性。为提高现有板料成形有限元法的计算效率,同时保证模拟精度,在一步快速成形有限元法的理论基础上,研究多步快速成形有限元法,通过引入中间构形的方式来考虑板料成形过程中加载路径与变形历史的影响。中间构形的构造是多步快速成形有限元法的关键,采用解耦思想将中间构形分解为弯曲变形和拉伸变形两个独立的过程进行计算。在弯曲变形阶段,不考虑材料的流动,根据板料与模具之间的位置关系计算获得滑移约束面;在拉伸变形阶段,材料的流动限制在滑移约束面上,通过应力平衡迭代以及节点修正后获得中间构形。以典型的钣金零件为例进行成形模拟,与现有商业有限元软件在计算精度和效率上进行对比,验证了该算法的可行性和有效性。结果表明,所提出的算法能够快速地构造出合理的中间构形,且能够准确地预测零件的成形性和厚度分布。Sheet metal parts are important parts of aircraft body and automobile body,in order to shorten the production cycle of sheet metal parts,finite element method is used to evaluate the manufacturability of parts in the initial stage of part design.In order to improve the calculation efficiency of the existing finite element method of sheet metal forming and ensure the simulation accuracy,based on the theory of one-step quick forming finite element method,multi-step quick forming finite element method was studied.The influence of loading path and deformation history in sheet metal forming process is considered by introducing intermediate configuration.The structure of intermediate configuration is the key of multi-step quick forming finite element method,the intermediate configuration is decoupled into two independent processes of bending deformation and tensile deformation,which were calculated.In the bending deformation stage,the slip constraint surface is calculated according to the position relationship between the sheet and the die without considering the material flow.At the stage of tensile deformation,the material flow is restricted to the slip constraint plane,and the intermediate configuration is obtained through stress balance iteration and node modification.Taking a typical sheet metal part as an example to simulate the forming,and comparing with the existing commercial finite element software in calculation accuracy and efficiency,the feasibility and effectiveness of the algorithm are verified.The results show that the proposed algorithm can quickly construct reasonable intermediate configuration and accurately predict the formability and thickness distribution of parts.

关 键 词：多步快速成形有限元法 中间构形 解耦计算 滑移约束面 钣金成形 

分 类 号：V262[航空宇航科学与技术—航空宇航制造工程] U466[机械工程—车辆工程]