改进模拟退火算法的喷管动力学模型修正

To obtain the high-precision structural dynamics FE (Finite Element) model of a liquid rocket engine nozzle, a method for updating the FE model is proposed based on the improved simulated annealing algorithm (ISAA). First, a parametric FE model of the nozzle is established, in which the nozzle is modeled as a laminated composite shell. The structural modal parameters are treated as the reference base, followed by constructing the objective function using the combined modal frequencies and shapes. The design variables are extracted utilizing the sensitivity analysis. Based on the above ideas, the optimization model is established. Then, the ISAA with the functions of memory and local-searching is proposed and applied to the multi-objective global optimizing in the design space. The model updating software ZDXZ-V1.0 of structural dynamics, is developed based on the MSC Patran/Nastran software platform. Finally, the effectiveness of the model updating method is also examined by applying it to a liquid rocket nozzle. The results indicate that the relative errors of the first three-order modal frequencies are less than 2% compared to the experimental data. The minimal MAC value of the shape correlation is greater than 0.9 while the dynamic conformance of the nozzle model is improved remarkably. The model precision can meet the requirements of engineering applications. Consequently, the model updating strategy has been proven to be efficient and robust. It is suitable for updating the dynamics FE models of the large complex engineering structures.