低压母线系统振动与声辐射特性分析

采用有限元与边界元法,以某型号母线桥为例,对低压大电流母线设备正常运行中噪声偏大的问题进行研究。建立母线桥有限元结构分析及边界元声学分析的三维模型。在求解系统固有频率及振型的基础上,应用有限元法完成了母线桥结构振动响应的数值计算。然后,将母线桥外表面的节点振动位移作为声学边界条件,采用边界元法计算了母线桥的辐射噪声特性,得到母线桥辐射声场的分布规律,确定系统中主要振源和声源的部位。根据分析结果提出了结构改进方法,计算和实验结果表明该方法控制噪声的可行性和有效性。

Vibration and Acoustic Radiation Characteristics of A Low Voltage Busbar Bridse System

The numerical analysis of vibro-acoustic characteristics of a certain low voltage busbar bridge system is carried out by use of structural finite element method(FEM)and acoustic boundary element method(BEM).A 3D FE structural model and a 3D BE acoustic model for it are developed.Its vibration response characteristics are calculated in terms of its natural frequencies and modal shapes by using FEM.Taking the outside surface node displacements of the busbar bridge system as acoustic boundary conditions,the acoustic characteristics of the system in near field are computed by using indirect BEM,and the main vibration source and sound source are found out.Based on the analysis,one feasible structure modification is present to control the noise.Results show that the proposed method can reduce the noise effectively.