材料参数拟合方法对弹靶侵彻仿真的影响

Influence of Different Material Constants Fitting Method on Predicting Warhead Impacting Metal Targets

弹靶侵彻仿真中材料参数对计算结果有着至关重要的影响。为寻求一套适用于弹靶侵彻仿真计算的材料参数拟合方法,借助前期开展的靶板材料动态力学性能试验、靶板材料断裂试验,通过不同拟合方法依次得到不同的 JC本构模型及失效模型参数,依据试验建立有限元计算模型,将数值计算结果与试验结果进行对比。结果表明:(1)对于同一材料的力学性能试验,采用不同的拟合方法可得到不同的 JC本构、JC失效参数,二者会对弹靶仿真结果造成一定影响;(2)在不考虑温度软化项的前提下,采用高应变率作为参考应变率进行拟合能更加准确地表征材料在高应变率下的应力-应变关系,更加适用于弹靶侵彻强瞬态、高应变率作用过程仿真;(3)对于同一 JC本构模型,采用平均应力三轴度拟合的 JC失效模型较采用初始应力三轴度拟合的 JC失效模型所得战斗部剩余速度计算结果偏小,仅采用拉伸试件结果拟合的 JC失效模型较采用扭转、拉伸试件结果拟合的 JC 失效模型所得战斗部剩余速度计算结果偏小。

Material constants played a significant role in the numerical prediction of warhead impacting metal targets, in order to obtain a set of valuable material constants fitting methods, JC strength model and JC failure model constants were acquired by different fitting method based on material mechanical properties and failure experiments. Simulation results were compared with experiment outcome in which different nose warhead penetrated different thickness metal plates, and it indicated:(1) simulation results could be distinct using JC strength model and JC failure mode constants from different fitting methods for the same material mechanical property tests;(2) JC strength model constants fitting by stress-strain curves using high reference strain rate were suitable for the numerical predicting warhead penetrating metal plates;(3) JC failure model constants fitting by initial stress triaxiality or average stress triaxiality had few influence on calculation results. This research could provide assistance for the material constants fitting method in numerical simulation.