空调室外机系统的实验模态分析与模型更新

Experimental modal analysis and model updating on outdoor unit of conditioner

有限元(Finite Element,FE)模型的正确性和可靠性对于确保结构仿真达到其分析目的相当重要。文章介绍了空调室外机(Outdoor Unit of Conditioner,OUC)有限元模型的建模技术与模型更新。建构OUC的有限元模型必须呈现结构的物理特性,包括几何形状、材料性质、接触接口和边界条件等,并施以实验进行验证。一般的方法是对结构进行实验模态分析(ExperimentalModalAnalysis,EMA)以获得结构模态参数。同时,也可由有限元模型的数值分析求得理论模态参数。模型更新是调整有限元模型参数,使分析模型和实际结构的结构模态特性相符。结果显示,更新后的有限元模型在结构模态和频率域特性上,能充分呈现空调室外机实际结构的振动特性。

The correctness and reliability of finite element (FE) model is crucial to ensure structural simulation to fulfill its purpose. This work introduces the FE modeling techniques and model updating for outdoor unit of conditioner (OUC). The FE model of OUC must reveal the reality of structure, including geometry, material, interface and boundary conditions, and to be validated by experiments. The general approach is to perform experimental modal analysis (EMA) on the real structure and obtain structural modal parameters. At the meantime, the structural modal parameters can be numerically obtained from FE model. Model updating is to adjust the FE model such that both FE model and real structure are equivalent based on the agreement of structural modal characteristics. Results show the updated FE model of OUC can reveal good agreement with real structure in modal and frequency domain properties.