论文部分内容阅读
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 the safety and lightweight of automobiles, and its dynamic mechanical properties directly affect the vehicle crash safety. Based on the analysis of the dynamic mechanical properties of the advanced high strength steel for automobiles, two-phase high-strength steel HC500 / DP780 was selected and tested by ordinary mechanical tensile testing machine and hydraulic servo high-speed tensile testing machine to obtain 0.001 and 0.1 s ~ (-1) 2 kinds of quasi-static and 1, 10, 100, 200, 500 and 1000 s -1 uniaxial tensile test mechanical properties, and based on the Johnson-Cook equation obtained dynamic mechanical constitutive model. Based on the thin-walled beam drop-weight test platform for crushing performance analysis and the use of LS-DYNA simulation analysis, dynamic mechanical properties of materials and constitutive models for verification analysis. The results show that the trend of the model simulation and the experimental analysis are basically the same, indicating the accuracy of the model simulation and then the dynamic mechanical properties of the material and the accuracy of the constitutive model. With the increase of the collision rate, the energy absorption ratio of the pipe and the load ratio Are decreasing, indicating that the collision rate has some impact on the energy absorption characteristics of the pipe, as the collision rate increases, the energy absorption characteristics of the pipe is gradually reduced.