Structural Design And Strength Analysis Of Filament Wound Composite Shell For Rocket Engine

In this paper,370mm solid rocket motor was designed as the research object to meet the strength requirements for the filament wound composite shell,with the maximum working pressure of 25mpa.The result could provide some reference for the future of the same type of filament wound solid rocket engine shell.The main research results of this paper were as follows:(1)The structural characteristics of the solid rocket engine were analyzed with the mechanics of composite materials and structural mechanics.Combining the mechanics of composite materials and structural mechanics,and finding out the key points and difficulties of the design,the appropriate design theory and design scheme were chosen under the premise of design requirement.This provided the basis for the farther research of design and simulation.(2)The fiber winding shell was analyzed by the grid theory,and the double angle winding was carried out by means of the combination of the spiral winding and the circumferential winding.Two kinds of materials were used to design the shell structure.The front and back case head were designed to be equal stress case head,and each of which had 12 sections of variable angle and variable thickness spiral wound layer.According to the process parameters of the composite material,the number of fiber layer was designed,and a variety of ply programs were designed,and the theoretical verification was carried out.(3)The 3D shell model was established by FEM analysis software.Then the simulation of multiple ply programs by composite shell theory was analyzed.And the stress magnitude and deformation state of the structure under axial and radial conditions of each plan were obtained,and the effect of the stress on the sequence of fiber layer was analyzed.The method of the ply programs with high strength under the same conditions was summarized,and the best method of ply programs was extracted from the model,which was prepared for the finite element analysis of the solid model.(4)The 3D solid model including the shell and the front-and-rear metal joints was established,and the stress state of each layer was obtained by rationally dividing the mesh and the material assignment.The local coordinate system was established by post processing,the stress of the maximum stress of the annular layer and the spiral layer was obtained in the coordinate system of the material.The quality of the design of the filament wound shell and the quality of the engine metal shell subjected to the same internal pressure were roughly calculated and compared,and the strength of the fiber winding composite shell was demonstrated by comparison.