固体火箭发动机复合材料壳体破坏分析及优化

利用有限元计算软件ANSYS对轴向压力和弯矩联合作用下某型号固体火箭发动机复合材料壳体组合结构进行数值模拟。数值计算与实验结果对比分析表明:由于原结构的复合材料铺层设计不够合理,造成部分复合材料铺层局部应力过大,而导致结构未达到设计载荷即发生局部失效破坏。本文在结合实验分析和实物模型数值模拟计算的基础上,提出两种措施对原结构进行优化改进:增加局部补强纵向铺层数目以提高局部承载能力,从而提高整体承载能力;改变个别铺层材料以增强该层材料本身承载能力,最终提高整体承载能力。数值计算结果显示,两种改进结构均能提高整体结构承载能力15%～20%,实物实验表明改进结构可达到原结构设计承载能力的115%以上。

Analysis of Failure and Optimization for Composite Case of Solid Rocket Engine

Using FEM (Finite Element Method) calculation software ANSYS, the numerical simulation of the composite case of a solid propellant rocket engine under complicated loads including axial pressure and bending moment is studied.The comparison of numerical calculation results and experimental phenomenon show that the cause which leads to the premature failure of the structure under the anticipant capacity of bearing load is the improper laid layer design,which leads to some layers'stresses exceeding their bearing capacity.Two improved methods for the original structure are proposed.First,in order to increase the bearing capacity of the whole structure, more local reinforcement axial layers must be appended to increase the local bearing load capacity when the materials of all layers are uniform.Second,through replacing the material of the layer with the maximal stress by the material with more bearing capacity and keeping the other layers with the original material,the bearing capacity of the whole structure can be increased.The results of numerical simulation show that the two optimizing methods can markedly increase the bearing load capacity of the shell structure. Using optimization design methods,the bearing load capacity of the structure can be increased from 15% to 20%.And the experiment shows that the bearing load capacity of improved structure is more than 115%.