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为研究和模拟改性双基推进剂(CMDB)在准静态条件下的断裂特性,利用扩展有限元XFEM技术,建立了中心直裂缝含加载平台的圆盘形三维模型。基于线粘弹性理论,通过单轴拉伸实验直接获取改性双基推进剂的最大拉应力8.21MPa,作为仿真模型中裂纹粘聚区的断裂强度,模拟了固体推进剂在静态加载条件下裂纹实时扩展过程。结果表明实验和仿真过程中裂纹均首先呈I型扩展,最后以复合断裂形式扩展失效。讨论了推进剂在压缩断裂过程中裂纹扩展区的应力变化对裂纹扩展的影响,发现实验预期结果与仿真结果符合性良好,说明扩展有限元法能够为改性双基推进剂断裂过程的数值模拟提供新的方法。
In order to study and simulate the fracture behavior of modified double base propellant (CMDB) under quasi-static conditions, a three-dimensional disc-shaped three-dimensional model with center-cracked loading platform was established by using the extended finite element method (XFEM) Based on the theory of linear viscoelasticity, the maximum tensile stress of the modified double-base propellants is obtained directly by uniaxial tensile test, which is 8.21MPa. As the fracture strength of the cohesive zone in the simulation model, the crack of the solid propellant under static loading conditions is simulated Real-time expansion process. The results show that all the cracks in the experiment and the simulation process are first type I expansion, and finally expanded in the form of composite fracture failure. The effect of stress on the crack propagation in the crack propagation zone during the compression fracture was discussed. The experimental results are in good agreement with the simulation results, which shows that the extended finite element method can be used to simulate the fracture process of the modified double base propellant Provide new methods.