FEM-SPH adaptive method for dynamic analysis of the diaphragm's fracture in hypersonic impulse facilities

The shock tunnel is a key land-based test facility used to study the aerodynamic performance of supersonic aircraft. The diaphragm is an essential component of the shock tunnel test, which acts as the trigger device. The critical rupture pressure of the diaphragm is significant because it determines the operating conditions for the shock tunnel test. However, when the diaphragm ruptures, it generates fragments that can pose risks to the safe operation of the test equipment. The finite element method (FEM) is the most commonly used approach for analyzing the dynamic response of diaphragm rupture. While FEM can accurately predict the critical rupture pressure and rupture time, it has limitations in simulating the fragments produced during the rupture process. This paper proposes a method for calculating the dynamic response of a shock tunnel diaphragm rupture by combining the finite element method and smoothed particle hydrodynamics (FEM-SPH) to address this limitation. This method has been verified for its accuracy in predicting critical rupture pressure and time. Additionally, the paper introduces a research method for characterizing the fragments using aggregated SPH particles. It analyzes the dynamic response characteristics of the diaphragm and the pieces during the rupture process.