基于热传导方程,时装有变截面星孔药柱的火箭发动机物理模型进行了合理简化,并根据推进剂材料的粘弹性本构关系,结合热流变简单材料的特性,对其受温度冲击栽荷的情况进行了数值计算,得到温度冲击载荷作用下药柱的实时温度场及应力.应变特性,分析了星尖处的应力随时间的变化及在药柱长度方向上的变化规律,得到药柱肉厚及温度冲击都会对应力产生影响;进一步讨论了随着扩张角增大,初始通气参量会下降很多,但药柱内最大应力值会有所增大,因此选取合适的扩张角,可权衡初始通气参量与最大应力之间的问题,对药柱设计有一定参考价值.%Based on the equation of heat conduction, the physical model of a rocket motor which loaded with variable section star grain was rationally simplified according to the viscoelasticity constitutive equations for solid propellants materials and the property of simple thermorhcological materials, the simplified model was numerically calculated when it suffered the temperature shock.The real-time temperature field and stress-strain behaviors of the grain under the temperature loading were obtained. The change law of stress in star tip varied with time and the direction along the grain9 axial direction were analyzed,which shows that the wall thickness and temperature shock will influence the stress value. Furthermore,the initial aerate parameter will decrease greatly following with the increasing of expansion angle, but the maximum stress will increase a bit. So the suitable expansion angle should be chocaed to optimize the relation between the initial aerate parameter and the maximum stress in grain, which have reference value to grain design.
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