基于断裂相场的高分子黏结炸药裂纹演化及其力学性能退化分析OA北大核心CSTPCD

In order to analyze the crack evolution process of polymer-bonded explosives(PBXs)and their mechanical behavior,a thermal-viscoelastic phase-field fracture model is proposed by considering the influence and mechanism of their elastic,viscous and thermal properties.Based on the proposed phase-field fracture model,a one-element model of the thermal-viscoelastic material is established,and the parameters are analyzed for different temperatures and strain rates.Then,based on the PBX,the simulation of the fracture phase field is performed and the model parameters are calibrated.Thus,based on the fracture phase field,the crack evolution of PBX material and its mechanical property degradation are further clarified from the meso-scale level under different strain rates and different ambient temperatures.The results show that the fracture driving energy and compressive strength tend to decrease with decreasing strain rate and increasing temperature,which delays the crack occurrence and the impede the crack propagation.