为了对某型大长径比固体火箭发动机在极端温度发射时的结构完整性进行分析,采用三维热粘弹性有限元方法,计算得到了推进剂药柱在内压、轴向过载和极端温度载荷(-40℃和+50℃)联合作用下的位移、应变和应力分布规律。研究结果表明,推进剂药柱在高温和低温发射时位移最大值分别为9.3mm和16.4mm,VonMises应变最大值分别为14.6%和23.5%,依据VonMises应变准则,安全系数分别为2.74和2.46,满足结构完整性要求。

A three-dimensional thermoviscoelasticity finite element method was used to analyze structural integrity of a rocket motor with large aspect ratio for its launching under extreme temperature. Displacement, stress, and strain fields of solid propellant grain were calculated under pressure loading, axial overload and temperature loading (-40°C & +50°C). The results demonstrate that the maximum displacements are 9.3 mm and 16.4 mm, the maximum Von Mises strain are 14.6% and 23.5%, the safety factor is 2.74 and 2. 46 at high temperature and low temperature respectively. According to the Von Mises strain criterion, the solid propellant grain is proved to meet the requirements of the structural integrity.