Numerical Simulation And Analysis Of Crack Propagation In PBX Specimen Based On Extended Finite Element Method

Nowadays,as the core component of all kinds of weapons,explosives will experience complex external loads during storage,transportation and launching.The common forms of loading include compression,shearing,and so on.These external loads can cause damage in the structure,decrease the stability and cause the risk of accidental explosion.Therefore,it is necessary to carry out the analysis of fracture related to it.The extended finite element method(XFEM)is a new research method for crack propagation.Using this method to study the crack propagation,the real-time updated crack propagation can be obtained.It also can avoid the complicated calculation caused by grid reconstruction.This paper intends to apply this method to simulate the crack propagation process of the PBX standard structure and analyze the simulation results.This article investigates the crack propagation behavior of polymer bonded explosives(PBXs).Firstly,the research status of the crack propagation and the extended finite element method of the PBX structure are expounded,and the factors that may affect the structure crack propagation process in the simulation are studied.Then research the related theory of crack propagation and the extended finite element method.And establish and simulate the numerical model of crack propagation of concrete three-point bending beam by ABAQUS according to the reference.Then compare with the experimental results in the literature to verify the accuracy of the method.Secondly,a PBX three-point bending beam model with pre-fabricated cracks is established and numerical simulations are conducted to investigate the crack propagation characteristics.Based on the method of controlling variables,build the global domain refinement,crack propagation domain refinement and practical restraint loading model of PBX three-point bending beam with pre-fabricated cracks.The effects of these three factors on the crack propagation and related parameters are compared and analyzed..Finally,the PBX warhead model was established,and the crack propagation simulations were performed under the lateral compression and forward impact conditions.The crack propagation process and related parameters of the structure were obtained,also got the weak points of the warhead structure.Then proposed some storage schemes to reduce the chance of cracks in the warhead structure due to external loads,thereby passively protecting the PBX warhead structure.