2219铝合金高应变速率本构模型及其电磁成形应用评估

High strain rate constitutive model and electromagnetic forming application evaluation for 2219 aluminum alloy

为探究2219铝合金电磁成形的高应变速率变形行为,采用分离式霍普金森拉杆和热模拟实验机,分别进行了高应变速率和高温准静态的铝合金拉伸实验,分析了不同温度和应变速率对2219铝合金流动应力的影响,并对传统J-C本构模型的应变速率项进行修正和优化。基于传统和优化的J-C本构模型分别建立了电磁成形有限元模型,并与电磁成形实验结果进行对比。结果表明:2219铝合金的抗拉强度随应变速率的提高先增后降,流动应力随温度的增加而逐渐降低。优化的OP J-C本构模型的拟合效果最佳,线性相关系数R和平均相对误差AARE分别为0.9975和1.06%。相比于传统J-C本构模型,优化的本构模型电磁成形模拟结果与实验值的吻合度更高,证实了优化的本构模型能够准确描述2219铝合金的高速率变形行为。

In order to explore the high strain rate deformation behavior of 2219 aluminum alloy during electromagnetic forming,the high strain rate and high temperature quasi-static tensile experiments of aluminum alloy were conducted by separate Hopkinson tensile rods and thermal simulation testing machine,and the influences of different temperatures and strain rates on the flow stress of 2219 aluminum alloy were analyzed.Then,the strain rate term of traditional J-C constitutive models was corrected and optimized.Furthermore,based on the traditional and optimized J-C constitutive model,the finite element models of electromagnetic forming were established respectively,and the experimental results of electromagnetic forming were compared.The results show that the tensile strength of 2219 aluminum alloy increases first and then decreases with the increasing of strain rate,and the flow stress gradually decreases with the increasing of temperature.The optimized OP J-C constitutive model has the best fitting effect,and linear correlation coefficients R and AARE are 0.9975 and 1.06%,respectively.Compared with the traditional J-C constitutive model,the electromagnetic forming simulation results of the optimized constitutive model are more consistent with the experimental values,which confirms that the optimized constitutive model can accurately describe the high-rate deformation behavior of 2219 aluminum alloy.