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用粘弹性有限元法,分别以尖角形、椭圆形、圆形裂尖反映裂尖的变形,以最大周向应力准则和最大能量释放率准则作为裂纹扩展方向的判断依据,以J积分作为裂纹扩展的起始判据,计算了不同倾斜角裂纹的初始扩展方向。采用多个扩展步递增循环计算的方法,得到了不同倾斜角裂纹的扩展路径,并在扩展路径上设置粘结损伤单元,模拟了裂纹的动态扩展过程。计算结果表明,考虑裂尖构形的影响可更准确地计算出裂纹的初始扩展角度,结合多扩展步循环计算方法和粘结损伤单元,可有效地模拟固体推进剂的断裂过程。
The viscoelastic finite element method was used to reflect the deformation of crack tip with sharp corner, oval and circular crack tip. The maximum circumferential stress criterion and the maximum energy release rate criterion were taken as the judgment basis for the crack propagation direction. J integral was used as crack Extended initial criterion, the initial expansion direction of the crack with different tilt angle is calculated. A series of incremental step-by-step cyclic calculation methods were used to obtain the extended path of different inclination angle crack. In the extended path, the bond damage unit was set up to simulate the dynamic crack propagation process. The calculation results show that considering the influence of the crack tip shape, the initial crack propagation angle can be calculated more accurately. Combined with the multi-step cycle calculation method and the bonding damage unit, the fracture process of the solid propellant can be simulated effectively.