强动载荷下焊接钢板力学性能及本构模型研究

为研究强动载荷下船用焊接钢板的力学性能。开展了典型船用焊接钢板母材、焊缝和热影响区的准静态拉伸试验、高温拉伸试验及SHPB动态压缩试验,分析了焊接钢板材料在不同应力状态下的力学行为,基于力学性能试验结果拟合了焊接钢板母材、焊缝和热影响区材料的本构模型。结果表明:准静态条件下,与母材相比,焊缝和热影响区材料的屈服强度与抗拉强度偏大,延伸率偏小;高应变率下,热影响区材料抵抗塑性变形的能力明显强于其他两种材料,且随着应变率的增加抵抗塑性变形的能力呈增强趋势;焊接板母材、焊缝与热影响区材料均表现出应变率效应和温度效应;热影响区是焊接板抗冲击性能相对薄弱的区域。建立的Johnson-Cook模型可以描述强动载荷下焊接钢板的力学性能。

A study on mechanical properties and a constitutive model of a welded steel plate under dynamic load

To study the mechanical properties of marine welded steel sheets under dynamic load,this study carried out quasi-static tensile tests,high temperature tensile tests and SHPB dynamic compression tests of typical marine welded steel base metals,welds and heat affected zones.The mechanical behavior of welded steel materials under different stress states was analyzed.Based on the mechanical properties test results,a constitutive models of welded steel base metal,weld and heat affected zone materials were fitted.The results show that under quasi-static conditions,the yield strength and tensile strength of the weld and heat affected zone materials are larger than that of the base metal and the elongation is smaller than that of the base metal.At high strain rate,the ability of the material in the heat-affected zone to resist plastic deformation is significantly stronger than the other two materials,and the ability to resist plastic deformation increases with strain rate.The welded plate base metal,weld and heat affected zone materials all exhibit strain rate effects and temperature effects.The heat affected zone is the area where the impact properties of the welded plate are relatively weak.The established Johnson-Cook model can describe the mechanical properties of welded steel plates under blast load.