全机有限元模型修正及验证方法研究

有限元分析现已成为飞行器设计的重要工具,若要提高有限元仿真的准确性,需要对有限元模型进行必要的修正。以某型直升机全机静力试验有限元模型为研究对象,基于静力试验实测的应变值,进行变量参敏度分析和模型优化,针对全机试验测点多、模型自由度大的特点,提出适用于验证全机模型的相关性算法;基于该算法,应用某一工况下的试验结果,对全机有限元模型的部分参数进行修正,得到与试验结果符合较好的模型参数结果;应用其他工况的结果对修正后的模型进行验证,结果表明:其他工况下修正后模型的计算结果与试验值也很接近,证明了该相关性算法和全机模型修正及验证方法的可行性和有效性。

The research of global FEM modal updating and verification method

FEM analysis has become an important tool for the design of aircraft. In order to improve the accuracy of FEM simulation, it is necessary to modify and update the FEM models. This paper took a global FEM of some helicopter as subject, based on strain response measured in static test experiment, a variable sensitivity analysis and model updating were performed. Because of the big numbers of measure points of the test and the huge degrees of freedom of the global FEM, and a new dependency arithmetic which was suitable for global model was firstly given. Based on the arithmetic and combined with the results of some test case, partial parameters of the global FEM were updated to attain a better conformance with the test results. At last, a verification with results of other load cases were performed and a conclusion was given that the conformance between test results and simulation results after the global FEM updating in other cases were also promoted as predicted, which proved the feasibility and effectiveness of the dependency arithmetic and the process of global FEM optimization.