固体推进剂双向拉伸试件优化设计及试验

Optimal design and examination study of biaxial tensile specimens for solid propellant

关键词:  固体推进剂  双向拉伸  有限元分析  优化设计  断裂延伸率

Key words:  Solid propellant  Biaxial tension  Finite element analysis  Optimization  Rupture elongation

摘要:

基于Kelly提出的十字形试件,设计了一种新型固体推进剂双向拉伸试件。利用ANSYS有限元软件对试件双向加载过程试验区中引起的应力应变的数值模拟,实现了十字形试件的优化设计,经过优化的试件在满足双轴试验要求方面有了明显的改进。通过对丁羟复合固体推进剂试件双向加载力学行为试验研究,获得不同拉伸速率双向拉伸应力—应变破坏曲线,为推进剂材料破坏分析的经验准则提供判据。结果表明,固体推进剂断裂延伸率的双向弱化效应很明显,双向加载比例为等双拉状态时,其双向断裂延伸率比单向断裂延伸率降低37.5%。

Abstract:

A new-style biaxial tensile specimen of solid propellant is designed,based on the cruciform specimens proposed by Kelly.By using the finite element analysis ANSYS,the stress and displacement of specimens in the test section is simulated and the optimization of the cruciform specimens is realized.The stress and displacement fields in the central test section exhibit an excellent homogeneity and the maximum equivalent Von-Mises stress corresponding to the central part of the test section.In particular,the mechanical behavior of the biaxial tensile for HTPB propellant are tested,and the stress-strain wreck curves of biaxial tension are obtained under different tension speed.These data offer criterion for the wreck analysis of propellant material.The results show that the biaxial weakening of solid propellant is remarkable,and the Von-Mises rupture elongation of biaxial tensile decline about 37.5% to uniaxial tensile while the biaxial loads are equivalent.