振动载荷下固体推进剂粘接界面剪应力及损伤分布

Study on Shear Stress and Damage Distribution at Bonding Interface of Solid Propellant under Vibration Load

为研究海洋环境对立式贮存值班状态固体推进剂粘接界面损伤分布的影响,监测了某型固体火箭发动机值班条件下的振动载荷并进行数据处理;开展在温差/重力载荷和温差/实测振动载荷联合作用下固体发动机燃烧室的模拟计算,提取了两种载荷历程下的粘接界面剪应力—时间历程,并获取剪应力沿界面分布规律;结合推进剂粘接界面剪应力拉伸破坏试验、剪应力幅值往复拉伸破坏试验所得的本构方程结果,近似计算界面累积损伤分布。模拟计算结果表明,两种载荷历程剪应力沿界面路径分布规律相近,前人工脱粘结构附近界面应力较其他位置大;随贮存时间增加,蠕变损伤和疲劳损伤呈线性增加趋势;贮存期间对应的剪应力水平下,界面各位置损伤相差不大,最大相差20%左右;忽略蠕变与疲劳作用对界面损伤的交互影响,发动机值班半年时,累积损伤为5.79%。

To study the influence of marine environment on damage distribution of solid propellant bonding interface in vertical storage,the vibration load of a solid rocket motor under duty condition was monitored and the data were processed.The simulation of solid motor combustion chamber under combined loadings of temperature/gravity and temperature/measured vibration was carried out.The shear stress—time process of bonding interface under two calculation cases was obtained and the distribution of shear stress along the interface was also acquired.According to the constitutive equation obtained by shear stress tension failure test and shear stress cyclic loading test of propellant bonding interface,the cumulative damage distribution of the interface was approximately calculated.Simulation results show that shear stress distribution along interface path in two loading process is similar,and the interface stress near the former artificial debonding structure are larger than those at other positions.The creep damage and fatigue damage increase linearly with storage time.Under the corresponding shear stress during the storage period,the damage of each position of the interface does not differ much with the maximum difference of about 20%.Ignoring the interaction effect of creep and fatigue on interface damage,the cumulative damage is 5.79%when the motor is on duty for half a year.