Q235B钢动态本构及在LS-DYNA中的应用

采用万能材料试验机和分离式霍普金森拉杆（SHTB）装置，对我国钢结构建筑中最常用的Q235B钢进行准静态拉伸实验、高温拉伸实验和动态拉伸实验。基于实验数据对LS-DYNA常用的3种动态材料模型Cowper-Symonds本构模型、Johnson-Cook本构模型、Zerilli-Armstrong本构模型进行了拟合，通过Taylor杆实验对3种本构模型进行验证和对比分析。结果表明:Q235B钢具有较为明显的高温软化和应变率强化效应；Cowper-Symonds本构模型可以较好地适用于工程领域低速碰撞的模拟；Johnson-Cook本构模型可适用于较大应变率范围内的模拟；不推荐Zerilli-Armstrong本构模型在工程低速碰撞领域中使用。

Dynamic constitutive model of Q235B steel and its application in LS-DYNA

In this work we conducted a quasi-static tensile test,a high temperature tensile test and a dynamic tensile test on Q235B steel,the most widely used in steel structures in China,using a multi-functional material testing machine and a split Hopkinson tension bar (SHTB) and,based on the test data obtained,fitted three frequently used material models,i.e.the Cowper-Symonds model,the Johnson-Cook model and the Zerilli-Armstrong model,in LS-DYNA.We then verified their validity by conducting Taylor impact tests.The results showed that Q235B steel was temperature and strain-rate sensitive,that the Cowper-Symonds model was applicable in low velocity impact simulations,that the Johnson-Cook model was suitable for simulations with a wider range of strain-rates,and that the Zerilli-Armstrong model was not recommendable for low velocity impact simulation.