摘要
针对拼焊板两侧材料力学性能差异造成的非均匀变形问题,提出了通过调节弹性模邵尔硬度来提高其均匀变形能力和整体成形性。开展了不同加载工况下SS316/SS304拼焊板弹性模胀形实验,通过数字化图像相关技术获取了板材构型和应变分布,采用ANSYS/LS-DYNA有限元分析软件模拟分析了弹性模压力场和板材应力场。基于实验以及有限元分析结果,研究了弹性模邵尔硬度、拼焊板材质和板材壁厚等因素对金属拼焊板成形性能的影响规律。结果表明,随着弹性模邵尔硬度的增加,拼焊板的极限胀形高度降低,两侧胀形高度差值也减小,弹性模邵尔硬度为50~70 A时,板材的成形均匀性最好;弹性模/板料界面压力随弹性模邵尔硬度的增加而增大,导致SS316和SS304板料侧的应力比α从等双拉应力状态(α=1.0)向单轴应力状态(α=0)转移;而焊缝处的应力比α表现出先减小后增大的趋势,这与成形末段高邵尔硬度弹性模胀形件变形向中心区域的集中有关,是拼焊板极限胀形高度随弹性模邵尔硬度的增加而降低以及非均匀性减少的原因。
Aiming at the non-uniform deformation caused by the difference of mechanical properties between the two sides of the tailor welded blank(TWB),it was proposed to improve the uniform deformation ability and overall formability by adjusting Shore hardness of elastic dies.The elastic die bulging experiments of SS316/SS304 TWB were carried out under different loading conditions.The configuration and strain distribution of sheet metal were obtained by digital image correlation(DIC)technology,and the pressure fields of elastic dies and stress fields of sheet metal were simulated and analyzed by ANSYS/LS-DYNA finite element analysis software.Based on the results of experiments and finite element analysis,the effects of Shore hardness of elastic dies,materials quality of TWB,and sheet metal wall thickness on the formability of metal TWB were studied.The results show that with the increase of Shore hardness of elastic dies,the limit bulge height of TWB decreases,and the difference of bulge height between two sides decreases as well.When the Shore hardness of elastic dies is 50-70 A,the sheet metal shows superior formability uniformity.With the increase of Shore hardness of elastic dies,the interface pressure of elastic die/sheet metal increases,which results in stress ratioαat SS316 and SS304 sides transferring from equal biaxial tensile stress state(α=1.0)to uniaxial stress state(α=0).The stress ratioαat the weld seam decreases firstly and then increases,which is related to the localization of deformation of specimens bulged by elastic dies with larger Shore hardness towards central region at the end of the forming process,and also is the reason why the limit bulge height and deformation non-uniformity of TWB decreases with the increase of Shore hardness of elastic dies.
作者
王志飞
林永健
温光磊
许东方
相楠
WANG Zhi-fei;LIN Yong-jian;WEN Guang-lei;XU Dong-fang;XIANG Nan(School of Materials Science and Engineering,Henan University of Science and Technology,Luoyang 471000,China;Provincial and Ministerial Co-construction of Collaborative Innovation Center for Non-ferrous Metal New Materials and Advanced Processing Technology,Luoyang 471000,China)
出处
《塑性工程学报》
CAS
CSCD
北大核心
2023年第4期96-107,共12页
Journal of Plasticity Engineering
基金
国家自然科学基金资助项目(52275329,51905156)
中国博士后科学基金资助项目(2020M672221)
国家级大学生创新创业训练计划项目(202110464007)。
关键词
弹性模
金属拼焊板
加载工况
成形性
有限元分析
elastic die
metal tailor welded blank
loading condition
formability
finite element analysis
