初始缺陷对复合固体推进剂力学性能影响的数值研究

Numerical study of the influence of initial defects on the mechanical properties of composite solid propellants

为了研究复合固体推进剂中初始缺陷对其力学性能的影响,基于分子动力学算法生成了复合固体推进剂的细观颗粒填充模型,在颗粒/基体界面处设置粘接单元,并引入双线型内聚力模型描述界面层的力学响应,基于ABAQUS有限元数值计算平台研究了颗粒破碎、初始界面脱粘及微孔洞这些初始缺陷对推进剂损伤力学性能的影响规律。通过比较仿真应力-应变曲线,发现初始缺陷的存在严重劣化了推进剂的力学性能,具体表现为拉伸强度降低了40%,初始模量降低了40%。研究指出,颗粒/基体界面粘接性能对推进剂力学性能的影响最为显著,提高界面粘接性能可以大幅提高推进剂的力学性能,研究可为改善复合固体推进剂的配方研制及生产工艺提供一定的指导。

In order to study the effects of the initial defects on the mechanical properties of the composite solid propellants,the molecular dynamics algorithm was adopted to generate the mesoscale granular model of the solid propellant.The cohesive element was set between the particle and the binder interface and the bilinear cohesive zone model was employed to describe the property of the interface elements.The influence of the initial defects such as the particle breaking,the interface debonding and the micro holes on the propellants was studied based on the ABAQUS platform.Then these simulation stress-strain curves were compared and the result shows that the mechanical properties of the solid propellant have serious degradation due to the initial defect,embodied in the tensile strength of the propellant is reduced by 40% and the initial modulus is decreased by40%.It pointed out that the adhesive properties of particle/matrix interface have the most significantly influence on the mechanical properties of propellant and the propellant's property can be improved with the interface adhesive property improving.This study has some reference guidance to the optimization of composite solid propellant formulations and production technology.