CR1200/1800HS汽车热成形钢高应变速率力学性能和材料模型分析  

Analysis on mechanical properties and material model under high strain rate for CR1200/1800HS automobile hot formed steel

作　　者：杨浩 杨兴国 韩中海 Yang Hao;Yang Xingguo;Han Zhonghai(College of Intelligent Manufacturing and Automobile,Chongqing Technology and Business Institute,Chongqing 401520,China;School of Automotive Engineering,Wuhan University of Technology,Wuhan 430070,China;China Automotive Engineering Research Institute Co.,Ltd.,Chongqing 401122,China)

机构地区：[1]重庆工商职业学院智能制造与汽车学院,重庆401520 [2]武汉理工大学汽车工程学院,湖北武汉430070 [3]中国汽车工程研究院股份有限公司,重庆401122

出　　处：《锻压技术》2025年第2期242-249,共8页Forging & Stamping Technology

基　　金：重庆市教育委员会科学技术研究项目(KJQN202304013,KJQN202404004)。

摘　　要：以1800 MPa级车身用热成形钢CR1200/1800HS为研究对象,开展了其在动态载荷下的力学性能与本构模型的研究。首先,获取了6种应变速率下热成形钢的力学性能,并分析了关键参数的变化规律。然后,采用Voce+和Hockett-Sherby混合硬化模型获得了基准应变速率的有效应力-塑性应变的外延曲线,采用胀形试验与仿真对标,获取了混合模型的最优参数,并与各应变速率变化系数进行耦合,获取高应变速率材料模型。最后,采用车门防撞梁落锤冲击试验与仿真对比分析验证了模型的精度。结果表明:CR1200/1800HS钢的应变速率敏感性较低;高应变速率材料模型部分点位有效应力与试验对比偏差最大值小于3%;仿真获得的载荷-位移曲线与试验结果一致,关键参数偏差在5%以内,而采用准静态材料模型的偏差则在9%左右。结果表明所搭建的高应变速率模型精度较高,为此类碰撞分析提供了参考。For 1800 MPa grade hot formed steel CR1200/1800HS for automotive body,its mechanical properties and constitutive model under dynamic loading were researched.Firstly,the mechanical properties of hot formed steel were obtained under six kinds of strain rates,and the variation laws of key mechanical parameters were analyzed.Then,the effective stress-plastic strain extension curve of the reference strain rate was obtained by using Voce+and Hockett-Sherby hybrid hardening model,and the optimal parameters of the hybrid model were obtained by using bulging test and simulation benchmarking,which coupled with various strain rate variation coefficients to obtain the high strain rate material model.Finally,the accuracy of the model was verified by comparing and analyzing the impact test of door anti-collision beam and the simulation.The results show that the strain rate sensitivity of CR1200/1800 HS steel is relatively low.The maximum deviation of the effective stress at certain points of the high strain rate material model comparied with the test is less than 3%.The load-displacement curve obtained from simulation is consistent with the test results,and the deviation of the key parameters is within 5%,while the deviation using the quasi-static material model is about 9%.The results indicate that the accuracy of the high strain rate model constructed is high,which provides a reference for such collision analysis.

关 键 词：热成形钢 高应变速率 碰撞 材料模型 落锤冲击 

分 类 号：TG142.1[一般工业技术—材料科学与工程] U465.11[金属学及工艺—金属材料]