A Calculation Method for Shell Stress of Solid Rocket Motor

Abstract

The invention discloses a method for calculating the stress of the head of a solid rocket motor shell, which mainly includes the following steps: S1. Cutting out a unit body from the shell, and establishing a balance equation based on the symmetry condition and assuming that the membrane force is not close to the critical value ; S2, introduce two new variables, transform the balance equation into two second-order differential equations; S3, transform the two second-order differential equations into a fourth-order homogeneous linear differential equation; S4, use two adjacent shells The differential equation is solved according to the handover conditions of the elements, and then the stress distribution around the head is calculated. This method is used to calculate the orthotropic rotating surface shell bearing axisymmetric load under small internal pressure. On the complex shape surface with variable angle, variable thickness and variable stiffness, the precise control equation of the head is used, The magnitude and distribution of the linear stress of the head are solved by the slice analysis method, and the results are in good agreement with the finite element results, which can provide a theoretical basis for the strength analysis of the head of the solid rocket motor casing.

Description

technical field [0001] The invention relates to the calculation of the complex surface stress of a composite material head, in particular to a method for calculating the stress of a solid rocket motor casing. Background technique [0002] Fiber-reinforced composites have a series of advantages such as high specific strength, specific stiffness and designable properties, which make them widely used in aviation, aerospace, medical treatment and automobiles. At present, solid rocket motor casing composite materials have entered the research stage of carbon fiber / epoxy resin composite materials on the basis of early glass fiber / epoxy resin composite materials. High-performance composite materials make solid rocket motor casings better. Meet its "light" and "reliable" requirements. Carbon fiber has high stiffness, but at the same time it is also a typical brittle material. Therefore, the carbon fiber composite shell is more sensitive to the stress concentration of metal joints. ...

AI Technical Summary

Problems solved by technology

[0005] In order to check the strength of the solid rocket motor shell and overcome the defects of complex modeling process and lengthy calculation time of the existing finite element software, the present invention utilizes the basic knowledge of elastoplastic mechanics, combined with the relevant knowledge of composite material mechanics, from the essence of mechanics Carry out mechanical analysis on the complex shape of the head of the rocket motor shell, so as to provide reference for the rationality of the layup design and structural optimization of the solid rocket motor shell

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