ANSYS二次开发在火箭发动机法兰结构设计中的应用

Application of ANSYS secondary development in design of flange structure for rocket engine

氢氧液体火箭发动机密封连接形式常采用一种法兰面贴合的榫槽式密封法兰结构,设计时主要采用有限元方法进行结构强度和密封性分析。为提高设计效率、简化有限元操作,利用ANSYS提供的用户界面设计语言(UIDL)和参数化设计语言(APDL)二次开发环境,开发结构分析程序模块。该程序模块能够将法兰结构有限元分析的前后处理和计算封装在后台操作,用户只需输入结构和材料参数,程序可自动进行有限元计算。利用有限元计算结果,通过垫片应力预测泄漏率进行密封性分析,结合螺栓和法兰最大应力,可确定垫片规格等结构参数和拧紧力矩等装配参数。通过实际应用验证,根据程序计算结果满足发动机热试车使用要求,验证计算方法合理。

The flange structure with tenon-mortise sealing is widely used in LOX/LH rocket engine. FEM is usually used to analyze the sealing performance and stmc^ral strength in the design process of the flange structure. To improve the efficiency of design and simplify finite element operation, the secondary development environment of the user interface design language （UIDL） and ANSYS parameter design language （APDL） provided in ANSYS is used to develop the structure analysis program module. The program module can package the preprocessing-postprocessing and calculation of the flange structure finite element analysis for operation at backstage. The program can make the FEM calculation automatically when users input the structure and material parameters only. The leakage rate is predicted by means of the gasket stress to perform the hermeticity analysis according to the FEM calculation results. The gasket specifications and tightening torque can be determined in combination with the maximum stress of bolt and flange. The practical application result proves that the program calculation result can meet application requirements of the engine fire test, and the verification calculation method is rational.