中文摘要：

以点焊连接闭口帽形结构为例,选择3种典型高强钢材料,比较了不同板厚结构的轴向冲击特性.分析了冲压成形过程造成的帽形结构局部几何和材料属性变化,对该过程进行了数值仿真,将成形结果映射至碰撞仿真模型中,比较了成形因素对不同模型的影响,并与理论解析解进行了比较.研究结果表明：冲压成形过程导致结构局部减薄和材料加工硬化,对双相钢的影响最为明显;引入成形因素改变了轴向冲击变形的屈曲方式和后继变形模式,在先进高强钢材料的碰撞仿真中不可忽视;平均冲击力数值仿真结果与理论解析解存在一定偏差,但均表明双相钢具有更优良的变形吸能特性.

英文摘要：

Thin-walled column structures absorb large amount of energies during vehicle collision,and it is necessary to study the impact properties of these structures with the extensive use of advanced high strength steels.Spot-welded closed-hat structures made of three grades of high strength steels were selec-ted,and their axial crash performances with different sheet thickness were compared.The changes of local geometry and material property caused by stamping were investigated,then the numerical simulation of stamping process was carried out and the forming residual data were mapped into the crash models.The influence of forming data on different models was studied and the predicted mean impact forces by numerical simulation were compared with those predicted by theoretical formula.The results show that the stamping process makes the structure local thinning and material work-hardening,which are more obvious for dual phase steel;introducing forming residual data changes the buckling manner and sequential deformation mode of the axial crash deformation.Therefore the forming history can not be ignored during the crash simulation,especially for advanced high strength steels.Although there are some deviations between the numerical simulation results and theoretical solutions of mean impact forces,they both show that dual phase steel has better deformation energy absorption capacity than the others.