铝合金W型防撞梁超低温冲压仿真与实验研究  

Simulation and experiment study on cryogenic stamping for W-shaped aluminum alloy anti-collision beam

作　　者：戚宇彤 李淑慧[1,2] 钱昌明 冯彬[1,2] 顾彬 QI Yu-tong;LI Shu-hui;QIAN Chang-ming;FENG Bin;GU Bin(State Key Laboratory of Mechanical System and Vibration,Shanghai Jiao Tong University,Shanghai 200240,China;Shanghai Key Laboratory of Digital Manufacture for Thin-walled Structures,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学机械系统与振动国家重点实验室,上海200240 [2]上海交通大学上海市复杂薄板结构数字化制造重点实验室,上海200240

出　　处：《塑性工程学报》2024年第11期82-89,共8页Journal of Plasticity Engineering

基　　金：国家重点研发计划(2019YFA0708803);国家自然科学基金资助项目(52005330)。

摘　　要：以预时效态7075铝合金为实验材料,采用热传导和热力耦合分析建立了包括模具液氮制冷、板料液氮喷淋和冲压成形的W型防撞梁超低温冲压仿真流程,使用温度相关的材料本构以及分区网格划分方法建立了有限元数值模型,并进行了超低温冲压实验验证。搭建了超低温界面热传导系数测试平台,采用反传热法求解得到了超低温界面热传导系数。结果表明,随着温度的降低,超低温界面热传导系数增大,温度为-165℃时超低温界面热传导系数为2 kW·m^(-2)·℃^(-1)。在模具液氮制冷后,下模具表面的最低温度为-58.5℃,整体预测误差小于5.2%。在板料液氮喷淋后,预测的板料中部区域温度为-163.5℃,接近实验测试温度-160℃。W型防撞梁的特征小圆角过渡区为关键变形区,该区域的成形温度需低于-150℃,以保证成形性能。Taking the pre-aged 7075 aluminum alloy as experimental material,the cryogenic stamping simulation process of W-shaped anti-collision beam including liquid nitrogen refrigeration of die,liquid nitrogen spraying and stamping of sheet metal was established using heat transfer and thermal-mechanical coupling analysis.The finite element numerical model was established using temperature dependent material constitutive and partition meshing method,and the cryogenic stamping experiment verification was carried out.The testing platform for cryogenic interfacial heat transfer coefficient was established.The cryogenic interfacial heat transfer coefficient was solved by the inverse heat transfer method.The results show that the cryogenic interfacial heat transfer coefficient increases with the decrease of temperature.The cryogenic interfacial heat transfer coefficient is 2 kW·m^(-2)·℃^(-1) at-165℃.After the liquid nitrogen refrigeration of the die,the minimum temperature of the lower die surface is-58.5℃,and the whole prediction error is less than 5.2%.After the liquid nitrogen spraying of the sheet metal,the predicted temperature in the middle area of the sheet metal is-163.5℃,which is close to the experimental temperature of-160℃.The transition areas of featuring small round corner in the W-shaped anti-collision beam are the key deformation areas.The forming temperature in these areas needs to be lower than-150℃to ensure the forming performance.

关 键 词：超低温冲压 界面热传导 预时效态铝合金 防撞梁 温度场 

分 类 号：TG146.21[一般工业技术—材料科学与工程]