Structural response analysis of a solid rocket motor with HTPB propellant grain under vertical storage condition

HTPB推进剂装药发动机立式贮存结构响应分析

¹ Science and Technology on Combustion, Internal Flow and Thermal-Structure Laboratory, Northwestern Polytechnical University, Xi′an 710072, China
² Xi′an Institute of Aerospace Propulsion Technology, Xi′an 710025, China

Received: 13 July 2021

Abstract

Aiming at the structural response characteristics of solid rocket motor (SRM) under vertical storage conditions, the creep tests of HTPB propellant under different stress levels were carried out, and the creep constitutive model of the propellant was fitted. Then the creep model of the HTPB propellant was used to analyze the structural response of a solid rocket motor with HTPB propellant grain. At the same time, a two-week vertical storage experiment was conducted for the SRM with HTPB propellant grain, and the creep displacement of the front and rear end of the propellant grain was measured and compared with the simulation results. The results show that the creep model of the HTPB propellant can well simulate the structural response of the propellant grain under vertical storage condition. During the storage process, the position near the root of the front artificial relief flaps is the high stress area of propellant grain. After 1 year of vertical storage, the axial sinking displacement at the rear end face of propellant grain is about 1.38 mm.

摘要

为了获得固体发动机在立式贮存条件下药柱的结构响应特性，针对HTPB复合固体推进剂开展了不同应力水平下的蠕变试验，并拟合了蠕变本构模型。采用建立的推进剂蠕变本构模型对某发动机开展了立式贮存条件下的结构响应分析，获得了贮存过程中发动机药柱应力应变变化规律。针对该发动机设计开展了为期2周的立式贮存试验，测试获得了贮存过程中药柱前后端面的下沉位移变化，并与仿真结果进行了对比。结果表明，建立的推进剂蠕变本构模型可以较好地模拟药柱立贮过程中的蠕变响应，贮存过程中前人工脱黏层根部位置处为药柱的结构薄弱位置，立式贮存1年后其药柱底部端面轴向下沉位移约为1.38 mm。