基于表面粘结损伤的复合固体推进剂细观损伤数值模拟

Numerical Simulation of Solid Propellant Mesoscopic Damage Using Surface-Based Cohesive Approach

关键词:  固体推进剂  细观力学  界面损伤  数值模拟

Key words:  Solid propellant  Mesomechanics  Interfacial damage  Numerical simulations

摘要:

为更准确地模拟固体推进剂的细观损伤,研究复合固体推进剂的非线性力学性能,采用分子动力学方法对高填充比复合固体推进剂细观模型进行建模,验证了Surface-based cohesive方法的可行性,并替代经典粘结单元模拟了复合固体推进剂细观颗粒与基体之间界面损伤的产生和聚合。通过对比固体推进剂细观模型的计算结果,研究了复合固体推进剂颗粒粒径、位置的随机分布对固体推进剂细观损伤及宏观力学性能的影响。结果表明,采用Surface-based cohesive方法对固体推进剂细观模型较易进行有限元前处理,易收敛,计算结果比较合理。

Abstract:

To better simulate microscopic damage of solid propellant and study the non-linear mechanical properties of solid propellant, the molecular dynamics method was adopted to match the size distribution and volume fraction of solid propellants. The Surface-based cohesive approach was verified to be a better method to replace the cohesive element approach. It was developed to simulate the interfaces damage between particles and bind. Several mesosopic samples considering contact damage behavior were computed, and the effects of particle size and particle random distribution on the damage or mechanical property of solid propellant were discussed. The results show that the Surface-based cohesive approach is easier to be adopted to establish the interfaces between particles and bind in the pre-process of FEM. It makes the calculation of the FEM model more likely to converge and the results more reliable.