The Shape Optimization And Parameter Sensitivity Analysis Of Solid Rocket Motor

Structural integrity is one of the vital criteria for Solid Rocket Motor (SRM) design. It is shown that, the optimization of grain shapes and material properties could greatly improve the structural integrity of SRM. In this paper, the basic discipline and method of structural optimization are discussed, several grain models and geometric features are studied, and also, the material properties are optimized.The main achievements are summarized as follows:The conspectus on SRM structural integrity is put out firstly. The significance, history, status and correlative concepts are introduced. And the overview of structural optimization is also outlined, besides the software platform, MSC.Nastran.Basic theory and methods of structural optimization are discussed detailedly. Finite Element Method is addressed as a main solution to the structural analysis. The approximation model, built up on analysis results, referred by optimization direction and depth search, is investigated concretely. And some arithmetic are presented also, including constrain screening, convergence detection, sensitivity analysis, and so on.The two grain shapes, the tube and the star, are researched. Owing to particularity of shape optimization, the Basis Vector, which would guide the optimization procedure, is introduced. And the auxiliary models, which to help generate Basis Vectors, are also conducted. Considering the characteristic of SRM and its loads conditions, the plain-strain models of the tube and the star, are built up respectively. Each of them is analyzed under complex loads and boundary conditions. Several sensitivity factors of the shape parameters are studied emphatically, and the optimal schemes are discussed later.SRM containing slopeing groove, umbrella slot or debonded release boot is investigated. Although length geometric features do not have obvious influence on structural integrity as the plain figures, the three are usually of main bulk structure, and often have sharp influences on local structural integrity. In order to determine their optimal shapes, some structural ananlysis and sensitivy analysis are carried out.The possibility of application of isotropic and orthotropic materials on SRM is studied. The main components of SRM, propellant grain, insulation and case are equipped with isotropic and orthotropic materails respectively. The structural and sensitivity analysis are performed to each modulus of any component materials. And the ideal model about materials is promoted out, discussing the utility and availability of various materials on SRM.The achievements obtained in this dissertation provide an important guidance to the structural integrity analysis and optimization design on SRM. The methods and conclusions would be available for the designers, manufactures and users of SRM._____...