钢/聚氨酯夹层结构动态压缩力学性能与本构模型研究

Experimental study on dynamic compressive mechanical properties of steel / polyurethane sandwich structure and its constitutive model

基于霍普金森压杆(SHPB)装置,对高应变率下的钢/聚氨酯夹层结构进行了动态压缩实验,通过对不同厚度比的试样进行比较,建立了夹层结构的动态本构模型。实验结果表明,钢/聚氨酯夹层结构对应变率较为敏感,其屈服强度随应变率的增大而增大,且屈服强度的增幅随应变率的提高会有一定幅度的上升。基于Johnson-Cook模型,考虑厚度比对结果的影响,建立适用于钢/聚氨酯夹层结构的动态本构模型,并通过试验分析,确定了模型参数。利用实测应力应变曲线拟合的方法得到的钢/聚氨酯夹层结构的动态压缩本构模型,能描述不同厚度比的钢/聚氨酯夹层结构在高应变率下的应力应变关系,具有较高的精度。

A dynamic compressive constitutive model for steel /polyurethane sandwich structure with different thickness ratio under high strain rate was proposed based on the split Hopkinson pressure bar （SHPB）tests.The experimental results show that the steel /polyurethane sandwich structure is very sensitive to strain rate.The yield strength of steel /polyurethane sandwich structure is increased as the strain rate is raised and its increasing rate is greater than that of the strain rate.Based on the Johnson-Cook constitutive model,a dynamic constitutive model for steel /polyurethane sandwich structure with different thickness ratio was proposed.The parameters in the constitutive model were determined via the analysis of experimental tests.It can be concluded that the dynamic compressive constitutive model presented is effective and accurate to describe the stress-strain curve of steel /polyurethane sandwich structure.