微型固体脉冲推力器结构强度有限元分析

FINITE ELEMENT ANALYSIS ON STRUCTURE STRENGTH OF A SOLID IMPULSIVE MICROTHRUSTER

关键词:  脉动式火箭发动机  微型装药火箭发动机  有限元法  结构强度

Key words:  Impulse rocket engine  Micrograin rocket engine  Finite element method  Structural strength

摘要:

对用于飞行姿态控制和弹道修正的微型固体脉冲推力器的结构强度进行了动静态有限元分析， 考虑了脉冲推力器的结构设计特点和加工工艺， 模拟其台架静压试验和实际工作的载荷历程。数值分析结果表明， 当静态台架试验内压采用动压峰值时， 计算所得的结构应力、变形及其分布与模拟推力器实际工作过程的动态峰值应力、变形及分布具有较好的比拟性； 燃烧室壳壁沿平行其轴线方向的破裂以及燃烧室与点火器壳体螺纹连接处退刀槽根部的开裂是推力器结构强度的主要破坏形式。计算预示与台架试验出现的相符

Abstract:

A static and dynamic finite element analysis(FEA) on a solid impulsive microthruster with the flight attitude control was presented. The design characteristics and technological effect were considered during the numerical simulation of both the static deformation on test bed and real dynamic loading of the microthruster. Numerical results show that there exists a very similar comparison of the stress and deformation distribution between dynamic and static loading, where the static internal pressure in the combustion chamber is equal to the peak one of the dynamic load; and the major broken behaviors which parallel to the axis of the combustion chamber may appear at the roots of the technological grooves near the screw connetion between its chamber and igniter or and nozzle. The broken behaviors predicted by FEA agree with that observed in tests.