轴向冲击下薄壁方管屈曲模式及初始峰值力控制研究

On buckling mode and initial peak force control of thin-walled square tube under axial impact

基于冲击试验和仿真实验手段对带隔板方管吸能结构的碰撞力学响应特性进行分析,建立有限元模型,采用显式动力有限元ANSYS/LS-DYNA进行数值仿真,并与试验结果对比,误差基本稳定在5%以内,验证该数值仿真模型的有效性。研究结果表明:结构变形模式为稳定可靠的轴对称模式。研究隔板结构与诱导结构对吸能特性的影响,得出结构在隔板的约束下产生更多的屈曲褶皱,吸能量提高17%。诱导结构对结构整体吸能量影响不大,可以显著降低结构的初始撞击力峰值,降低百分比达到42.3%。

Based on impact experiments and virtual simulation tests,the mechanical response characteristics of square tube structure with diaphragms that can absorb energy were analyzed.The finite element model was established,and the explicit dynamic finite element ANSYS/LS-DYNA was used for numerical simulation.When compared with the experimental results,the relative error was less than 5%,thus verifying the validity of the numerical model.The experimental and simulation results show that the deformation mode is stably and reliably axisymmetric.Then,the influences of diaphragms and trigger structure on energy absorption characteristics were studied.It is concluded that more buckling folds are produced under the restraint of diaphragms,and the energy absorption increases by 17%.The induced structure has trivial effect on the overall energy absorption,but can significantly reduce the peak value of the initial impact force by 42.3%.