基于灵敏度分析的柴油机机体有限元模型修正方法

Finite Element Model Correction Method of Diesel Engine Airframe Based on Sensitivity Analysis

基于动力学模型修正理论,选取某型柴油机机体为研究对象,结合机体自由模态试验结果,对机体有限元模型修正方法进行研究。在分析机体有限元建模误差的基础上,以参数型模型灵敏度修正方法为基础,选取机体某些部位为修正区域,以弹性模量为修正参数,基于模态频率构建目标函数。结果表明:修正后模态参数与试验更为接近,提高了模型的精度,为柴油机有限元动力学建模奠定了基础。

Based on the dynamic model correction theory, a certain type of diesel engine body is selected as the research object, and the finite element model correction method of the body is studied in combination with the free modal test results of the body. On the basis of analyzing the finite element modeling error of the airframe,and based on the parametric model sensitivity correction method, some parts of the airframe are selected as the correction area, the elastic modulus is used as the correction parameter, and the objective function is constructed based on the modal frequency. The results show that the modified modal parameters are closer to the test, which improves the accuracy of the model and lays a foundation for the finite element dynamic modeling of diesel engines.