2124铝合金热成形本构模型及工艺分析  

Constitutive model and process analysis on thermoforming of 2124 aluminum alloy

作　　者：郭元恒 谢延敏[1] 王东涛 赵江波 杜凌峰 Guo Yuanheng;Xie Yanmin;Wang Dongtao;Zhao Jiangbo;Du Lingfeng(School of Mechanical Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学机械工程学院,四川成都610031

出　　处：《锻压技术》2022年第2期213-219,共7页Forging & Stamping Technology

基　　金：四川省国际创新合作项目(2020YFH0078);四川省科技计划资助项目(2019YFG0313)。

摘　　要：为了获得2124铝合金热变形下的力学行为,在温度为350~450℃、应变速率为0.001~0.1 s^(-1)的变形条件下进行热拉伸实验,获得了材料的应力-应变曲线,其结果表明:峰值应力随着温度的升高和应变速率的降低而减小;温度是影响伸长率的主要因素,且低应变速率下,具有较小的均匀伸长率。为精确地描述材料热变形下的变形行为,建立了粘塑性本构模型,并采用遗传算法求得该本构模型的材料参数,结果表明模型的预测值与实验值吻合程度较高。基于已建立的本构模型开发了用户材料子程序VUMAT,建立了双C件有限元模型,并利用ABAQUS软件对2124铝合金热成形过程进行了仿真分析。基于正交实验,研究了温度、冲压速度、压边力和摩擦因数对双C件成形后最大减薄率的影响,使用极差分析方法获得了较优的成形工艺条件,并通过实验验证了该工艺条件下的成形结果。In order to obtain the mechanical behavior of 2124 aluminum alloy under thermal deformation,the thermal tensile test was conducted at the temperature of 350-450℃and the strain rate of 0.001-0.1 s^(-1),and the stress-strain curves of material were obtained.The results show that the peak stress decreases with the increasing of temperature and the decreasing of strain rate,the temperature is a main factor affecting elongation rate,and there is a smaller uniform elongation rate at the low strain rate.In order to accurately describe the deformation behavior of the material under thermal deformation,a viscoplastic constitutive model was established,and material parameters of the constitutive model were obtained by genetic algorithm.The results show that the predicted value of the model is in good agreement with the experimental value.Based on the established constitutive model,the user material subroutine VUMAT was developed,the finite element model of double C part was established,and the thermoforming process of 2124 aluminum alloy was simulated and analyzed by software ABAQUS.Based on orthogonal experiment,the influences of temperature,stamping speed,blank holder force and friction coefficient on the maximum thinning rate of double C part after forming were studied,the better forming process condition was obtained by the range analysis method,and the results of forming under the process conditions were verified by experiment.

关 键 词：2124铝合金 热拉伸 本构模型 应变速率 伸长率 

分 类 号：TG146.2[一般工业技术—材料科学与工程]