新增表面等效作用力模拟固体推进剂裂纹动态扩展

固体推进剂作为线粘弹性材料在裂纹扩展过程中，外力和体力对体系作功的同时，材料的粘性内耗散和断裂表面能释放使体系能量降低。将裂纹扩展新增表面上等效作用力的概念引进有限元中，计算裂纹扩展过程中的应力强度因子和断裂表面能释放对体系应力应变场的影响，从而使得有限元可以模拟计算固体推进剂裂纹的动态扩展过程，解决了固体推进剂非定常燃烧扩展模拟中的难题。

Kinetic extension of the solid propellant cracks simulated by the equivalent forces working on the virtual new surfaces

The crack extension of the solid propellants,as linear viscoelastic material,would be influenced by the work of external forces and body forces the visco inner dissipation and the release of fracture surface energy The idea of the equivalent forces working on the virtual growing new surfaces of crack was introduced into FEM analysis to calculate the stress intensity factors and the influence of the fracture surface energy release to the stress fields when the crack was expanding So it is possible using the FEM to simulate the kinetic extension of the solid propellant cracks