Study On Shock Response Characteristics Caused By The Fracture Of Separation Plate In Expansion Tube Separation Device

The assessment and improvement of the shock environment during explosion separation has always been a major concern in the field of aerospace engineering.Whether the shock environment in the separation process can be effectively improved is even directly related to the success or failure of a space launching task.In this paper,the shock environment during separation of the typical expansion tube linear separation device was investigated.The influence caused by the fracture of separation plate was focused on,of which two key factors,material properties and fracture patterns,were studied experimentally and numerically.Firstly,separation process of the expansion tube separation device and the potential shock sources during the separation process were analyzed based on the simplified model of the separation device.Additionally,two single shock source modes were established,and the proportions of the impact of flat tube and the fracture of separation plate was quantitatively analyzed.Then,the dynamic tensile experiment and shock test of four kinds of materials with palpable difference in material properties were implemented based on Split Hopkinson Tensile Bar platform.Meanwhile,combined with the simulation results of the tensile tests,the influence on shock response characteristics caused by material properties were investigated and the crucial material parameters with prominent effect were point out.Furthermore,five kinds of samples with different loading angles were designed for mixed-mode dynamic fracture experiments and shock tests,and the shock response characteristics induced by different fracture modes were analyzed in combination with the simulation results of mixed-mode dynamic fracture.Finally,based on the experimental and numerical results of mixed-mode dynamic fracture,the structure of the separation plate was improved and the combined design scheme of the separation device was put forward,which can effectively reduce the shock caused by the fracture of separation plate.In this paper,the research methods and corresponding conclusions of the influence of the fracture of separation plate on the shock environment would contribute to the shock reduction design of expansion tube separation device.