逆法识别金属板材颈缩阶段应力应变曲线  

Identification of post-necking stress-strain curve for sheet metals by inverse method

作　　者：赵坤民[1] 范蓉[1] 王立民[1] 严建文[2] 

机构地区：[1]大连理工大学汽车工程学院工业装备结构分析国家重点实验室,大连116024 [2]合肥工业大学工业与装备技术研究院,合肥230601

出　　处：《塑性工程学报》2015年第6期161-169,共9页Journal of Plasticity Engineering

基　　金：国家自然科学基金资助项目(11472072)

摘　　要：金属板料成形过程的仿真需要定义材料在大应变处对应的流动应力曲线,即真应力-应变曲线。文章介绍了一种逆向识别方法,通过结合单向拉伸试验和有限元仿真分析来获得金属板料在大应变区间内的流动应力曲线。仿真分析过程中通过构建合适的有限元模型,正确模拟分散性失稳期间的各向异性塑性变形行为。在得出材料完整的直至颈缩阶段的流动应力曲线后,建立多个不同的硬化模型描述该曲线,并比较拟合结果,发现改进的Hockett-Sherby模型效果最好。Simulation of sheet metal forming requires the flow curve,i.e.,the true stress-strain relation,over large strains.This paper presents a method for obtaining the flow curve of sheet metals over a large range of strain through the combination of simple tensile test and finite element analyses.The appropriate finite element model for accurate simulation of the anisotropic plastic deformation during diffuse necking was established.Different hardening functions were evaluated for their capabilities in approximating the entire flow stress curves up to localized necking.A modified Hockett-Sherby function was found to present the best performance.

关 键 词：应力应变曲线 应力三轴性 拉伸试验 颈缩 逆法 

分 类 号：TB125[理学—工程力学]