Consequence analysis of premixed flammable gas explosion occurring in pipe using a coupled fluid-structure-fracture approach

A coupled fluid-structure-fracture approach incorporating a high-efficiency detonation modeling algorithm was proposed to study the consequences of premixed flammable gas explosion occurring in pipe. A strain-rate-dependent failure criterion which is the vital prerequisite for accurate consequences prediction was derived based on the failure mechanism of materials at high strain rates and it was applied to account for the fracture of pipe. The simulated pressure time history and fracture patterns were validated against experimental results and good agreements were acquired. The interaction between detonation wave and pipe during crack extension, dynamic fracture processes of pipes with different initial flaws, venting features of detonation products and pressure profiles out of pipe were obtained and discussed in detail. The comparison with existing semi-empirical and CFD methods was performed and it is revealed that the deformation and fracture of pipe have obvious negative influences on the peak overpressure and the rate of pressure increase out of pipe. Because the energy absorption and dissipation due to structural deformation and fracture are well taken into account, the coupled fluidstructure-fracture method is expected to provide more rational consequences prediction and analysis results.