基于薄壁梁落锤压溃高强钢动态力学性能分析  

Analysis on dynamic mechanical properties of high strength steel based on thin-walled beam crushing

作　　者：张伟 李春光 杨建炜 刘立现 王彦超 朱洪亚 

机构地区：[1]首钢集团有限公司技术研究院用户技术研究所,北京100043

出　　处：《锻压技术》2017年第10期174-179,共6页Forging & Stamping Technology

摘　　要：先进高强钢对汽车的安全性和轻量化具有重要影响,其动态力学性能直接影响到整车碰撞安全。针对汽车用先进高强钢的动态力学性能进行分析,选取双相高强钢HC500/DP780,分别采用普通力学拉伸试验机和液压伺服高速拉伸试验机,获得0.001和0.1 s^(-1)的2种准静态下以及1,10,100,200,500和1000 s^(-1)的6种高应变速率下的单向拉伸试验力学性能,并基于Johnson-Cook方程获得材料的动态力学本构模型。基于薄壁梁落锤压溃试验平台进行压溃性能分析,并采用LS-DYNA进行模拟仿真分析,以此对材料动态力学性能数据及本构模型进行验证分析。结果可知:模型仿真与试验分析的变化趋势基本一致,表明模型仿真的准确性,进而说明材料动态力学性能及本构模型的准确性;随着碰撞速率的增加,管件的吸能比以及载荷比都在减小,这说明碰撞速率对管件的吸能特性有一定影响,随着碰撞速率增加,管件的吸能特性逐渐降低。Advanced high strength steel has important influence on automobile safety and light weight, and its dynamic mechanical per- formance directly affects vehicle crash safety. For dual -phase high strength steel HCSOO/DP780, the dynamic mechanical properties of advanced high strength steel of automobile were analyzed, and the mechanical properties of uniaxial tensile tests were obtained by ordinary mechanical tensile tester and hydraulic servo high speed tensile testing machine under two kinds of quasi-static conditions of 0. 001 s^-1 and 0. 1 s^-1 and six kinds of high strain rates 1, 10, 100,200,500, 1000 s^-1. Then, the constitutive model of material dynamic mechanical properties was obtained by the Johnson - Cook equation. Furthermore, based on the analysis of crushing performance for the thin - walled beam, the simulation analysis was conducted by software LS - DYNA, and the material dynamic mechanical properties and constitutive model were verified. The results show that the simulation results are in good agreement with the experimental analysis, which indicates the accuracy of the model simulation as well as the accuracy of material dynamic mechanical properties and constitutive model. With the in- creasing of the collision rate, the energy absorption ratio and the load ratio of pipe are all reduced. The above results illustrate that the col- lision rate of pipe has a certain impact on the energy absorption characteristics, and the energy absorption characteristics of pipe are gradu- ally reduced with the increasing of collision rate.

关 键 词：高强钢 动态力学性能 本构模型 应变速率 压溃 薄壁梁 

分 类 号：TG142.15[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]