关键词: 固体推进剂火箭发动机;粘弹性;有限元法;药型结构设计+

Abstract: The low temperature mechanic property of the solid rocket motor is one of the most important qualitative criteria. Under low temperature loading, the serious stress and strain concentrations always occur at the top of the umbrella slot and can cause cracks in the concentrative position. The width and depth of the umbrella slot can be adjusted to release the stress and strain concentration in order to improve the mechanic property. With three-dimension viscoelastic finite element method, several finite element models of the motor grain with different width and different depth of fore umbrella slot were established. Under low temperature loading, the Von Mises strain fields of the grain were studied.The Von Mises strain fields of fore umbrella slot were obtained. The results show that the maximum Von Mises strain of the umbrella slot descends significantly with the increment of its width.Thus, adjusting the width of the umbrella slot is more useful than adjusting its depth. Then the suitable configuration of the umbrella slot can be obtained by synthesizing the demand of internal ballistic trajectory and produce technics. The analytical method and these conclusions are available for designing solid rocket motor grain configuration.

Key words: Solid propellant rocket engine;Viscoelasticity;Finite element method;Design grain configuration~+