考虑成形历史的双相钢薄壁结构轴向冲击试验与仿真研究  

Crash behavior test and simulation for a dual-phase steel thin-walled structure subjected to axial loading considering forming history

作　　者：牛建辉[1] 朱平[1] 

机构地区：[1]上海交通大学机械与动力工程学院上海市数字化汽车车身工程重点实验室,上海200240

出　　处：《振动与冲击》2012年第23期44-49,共6页Journal of Vibration and Shock

基　　金：国家自然科学基金项目(50875164)

摘　　要：金属板料塑性成形过程中局部厚度和力学属性将发生变化,进而影响成形结构的最终物理性能。针对双相钢DP590材料,以点焊连接闭口帽型薄壁结构为例,利用落锤冲击试验装置研究了冲压成形条件对结构轴向冲击变形行为的影响,并对该成形—冲击过程进行了数值模拟。试验结果表明:冲压成形构件冲击变形模式为非稳定的混合渐进—欧拉屈曲模式,且随成形压边力增加,构件冲击失稳现象加剧。相应仿真过程发现,引入冲压成形历史信息后,冲击仿真可较为真实地复现物理测试结果,为确保前期冲压成形仿真结果的可靠性,宜采用能够反应三维应力状态的七参数壳单元。Sheet metal forming process leads to changes in local thickness and material mechanical properties, those changes can further affect the final physical properties of thin-walled structures. Here, drop-weight impacting tests were performed for top-hat thin-walled structures made of a dual-phase steel, DP590 to investigate effect of stamping condition on their axial crash behavior. It was found that the deformation of stamped components shows an instable mixed progressive Euler buckling mode during the impacting process; moreover, with increase in blank holder torcc, the instability phenomena of the corresponding stamped specimen is aggravated. Numerical simulations were also conducted to reproduce the tested forming-crash process. It was shown that after introducing stamping history, the simulated collapse mode of top-hat structures can be closer to the observed physical tests. To ensure the reliability of introduced stamping history, a 7-parameter shell element with thickness stretch was suitable for simulation of sheet metal forming process.

关 键 词：双相钢 薄壁结构 冲压成形 冲击 

分 类 号：U463.04[机械工程—车辆工程]