复合圆柱壳冲击压缩数值模拟及稳定性研究

针对复合圆柱壳在炸药爆轰作用下的动力学响应及在此过程中伴随的失稳问题，研究了其制造工艺中可能出现的缺陷以及圆柱壳中铜线螺旋角和直径对复合圆柱壳稳定性产生的影响。采用SPH-FEM耦合算法，建立了复合圆柱壳二维细节模型，并提出了一种基于圆柱壳内壁粒子速度历史的失稳判据，计算了在不同参数条件下复合圆柱壳的失稳时间及对应的压缩率，对影响复合圆柱壳稳定性的因素进行了评估。分析结果表明，在复合圆柱壳制备过程中存在的折返层缺陷和铜线直径对复合圆柱壳的稳定性有较大影响，而螺旋角度对其稳定性影响不大。

Numerical simulation on stability of composite cylindrical shell under impact compression

For the dynamic response and the instability of the composite cylindrical shell under explosive loading, many factors may affect the stability behavior of the cylindrical shell. In this paper, three main aspects, i. e. the possible defects in the manufacturing process, the spiral angle and the diameter of the copper wire were investigated. Firstly, the 2D detailed model of the composite cylindrical shell was established to calculated the dynamic response under explosive loading, in which SPH-FEM coupling algorithm was applied. In order to verify the accuracy of the structural dynamic response by using the SPH-FEM model, the simulation results of the metal epoxy composite sleeve were compared, which demonstrated the reliability and numerical accuracy. Secondly, to evaluate the factors affecting the stability of the composite cylindrical shell, an instability criterion based on the particle velocity history of inner wall of the cylindrical shell was proposed. In this method, the velocity curve of the inner wall of the composite cylindrical shell was divided into three stages, and the time corresponding to the point of the velocity surge in the third stage was taken as the instability time of the composite cylindrical shell. Thus, the compression rate of the structure corresponding to the instability under different conditions could be obtained. The results show that the defects and the diameter of copper wire have great influence on the stability of the composite cylindrical shell, while the spiral angle has little influence. Moreover, in the manufacture process of the composite cylindrical shell, it is necessary to improve the quality as much as possible to ensure the integrity of the copper wire. In addition, the parameter of the copper wire diameter should be considered in the device design and experiment, since the copper wire diameter would directly affect the thickness of each layer of the composite cylindrical shell and the defect distribution of copper wire.