固体推进剂药柱立式贮存的蠕变效应

Research on Creep Effect of Solid Propellant Grain under Vertical Storage

为研究立式贮存固体推进剂药柱经长期自重载荷的蠕变效应,开展了推进剂在不同应力水平下的蠕变试验,根据试验结果拟合了推进剂恒温定应力蠕变本构方程,并与哑铃型试件ABAQUS模拟计算结果进行了相互验证;开展了发动机固化降温和重力联合载荷下的模拟计算分析,并对发动机立式贮存损伤其关键点及关键路径损伤进行了计算。结果表明,试验结果验证了Norton本构方程用于发动机蠕变分析的可行性;模拟计算分析表明发动机药柱整体有下沉的趋势,前后人工脱粘层均有不同程度的缝隙张开,前人工脱粘层附近张开最大,后人工脱粘层附近张开最小,轴向位移方向指向头部,药柱最大径向位移发生在中孔处;药柱中孔处应力要高于其他部位,药柱前翼锥段处应力最大,其蠕变损伤为0.49%;模拟计算结果与实际存储环境下拆卸发动机的结果相一致。

To study the creep effect of the solid propellant grains of vertical storage within long-term gravity load,creep tests of propellant specimens at different stress levels were carried out.Based on the experimental results,the creep constitutive equation at constant temperature and constant stress of propellant was fitted,and the verification was carried out with ABAQUS simulation results of dumbbell-shaped specimens.The simulation calculation and analysis of motor under combined loadings of curing cooling and gravity were carried out,and the motor′s vertical storage damage of the key points and key paths was calculated.The results show that the feasibility of applying Norton constitutive equation to creep analysis of motor is verified by the test results.The simulation results show that the whole grain of motor has the tendency of sinking,the gaps of fore and aft artificial debonding layer is opened in different degrees.The opening near the fore artificial debonding layer is the biggest,and the opening near aft artificial debonding layer is the smallest.The direction of axial displacement points to the head,the biggest radial displacement of the grain occurs on the middle perforation.The stress of middle perforation is bigger than that of the other areas,the stress in cone section of the fore wing of the grain is the biggest,its creep damage is 0.49%.Simulation results are consistent with ones of dismantling motor under the real storage environment.