推力室结构力学分析与优化设计

针对某液体火箭发动机推力室建立了参数化模型，使用有限元方法分析结构固有频率和振型，并进行了模态试验验证.采用最优拉丁超立方法进行计算机数值试验设计，得到了结构质量和1阶固有频率对于设计变量的敏感性，对于优化设计过程具有指导意义.使用NSGA-Ⅱ算法开展多目标优化设计，得到了同时满足静力学与动力学设计要求的推力室结构最优设计方案.最优设计方案的推力室质量减轻了9.1%，1阶固有频率值提高了22.6%，结果表明该方法能有效提高推力室的力学性能. 

Structural mechanics analysis and optimization design of thrust chamber

A parameterized model of a liquid rocket engine thrust chamber was established. Natural frequencies and vibration modes of structure were obtained by finite element method, and verified by modal experiment. Computer numerical design of experiments was conducted by optimal Latin hypercube design in order to get sensitivity of design variables for structural mass and first order natural frequency, which had a guiding significance for the process of optimal design. Multi-objective optimization was carried out using NSGA-Ⅱ algorithm, and the optimal structural parameters were obtained, satisfying both static and dynamic requirements. The mass decrease of the optimal design was 9.1%, meanwhile the first order natural frequency increase was 22.6%. The results show that the proposed method improves the mechanical property of thrust chamber effectively.