单层柱面网壳冲击试验研究

Experimental study on single-layer cylindrical reticulated shell under impact force

通过单层柱面网壳模型在冲击物作用下试验,研究单层柱面网壳在冲击作用下的动力响应和动力稳定性。利用动态应变仪和力、位移和加速度传感器,获取柱面网壳模型在冲击物作用下的冲击力、杆件应变、位移及加速度时程曲线。根据不同冲击力幅值与测点位移的对应关系,对网壳模型失效形式和破坏形态进行了动力稳定性分析并确定其稳定承载力。结果表明,实验测得的冲击荷载为三角脉冲荷载形式,持续作用的时间为15~35 ms,幅值和脉宽随冲击力增大而增大且与网壳结构的刚度性能有关。柱面网壳在冲击荷载作用下存在全局敏感性和局部敏感性杆件,模型具有较大的后屈曲抗冲击能力,在顶点垂直冲击下没有发生连续断裂。基于ANSYS/LS-DYNA建立了精细化试验模型,模拟单层柱面网壳的失效模式并与试验结果对比,验证了数值模拟方法的有效性。

Through the experiment for a single-layer cylindrical reticulated shell under impact forces,this paper is intended to study the dynamic response and the dynamic stability of a single-layer cylindrical reticulated shell.The time history plots of the impact force,axial stress,node displacements and accelerations have been obtained using the dynamic strain gauge,force sensor,displacement sensor and acceleration sensors.According to the corresponding relationship between the different impact force amplitudes and the measured point displacements,the failure modes and forms of the reticulated shell model in terms of the dynamic stability are analyzed and the stability bearing capacity is determined.The results show that the impact force on the model takes the shape of triangular impulse and the acting periods of the impact vary from 15 to 30ms,whose amplitude and width increase with the impact force and both are closely related with the model stiffness.There are global and local sensitivity rods for cylindrical reticulated shell under impact loads,which show strong shock resistance ability at post buckling while no continuous fracture under the vertex vertical impact.The detailed test model is established based on ANSYS/LS-DYNA in which the failure mode of the single-layer cylindrical reticulated shell has been simulated.After comparing the simulation results with the experimental results,the validity of the numerical simulation method is verified.