救护直升机机载急救单元随机振动分析

Random Vibration Analysis of an Integrated Airborne Aid Unit on Ambulance Helicopter

为了解某救护直升机机载综合急救单元随机振动响应特性,针对载机平台振动特点,将载机宽带随机叠加正弦振动激励谱转换为ANSYS软件可用的纯随机振动谱,在ANSYS软件中建立了机载综合急救单元有限元模型,通过模态分析,获取了机载综合急救单元固有频率和振型。在此基础上施加转换后的载机振动谱并进行随机振动分析,得到了机载综合急救单元不同部位在激励频带范围内的动力响应及危险频率点,并对单元结构动强度进行了校核。仿真分析结果可为机载综合急救单元的抗减振设计提供参考依据。

To understand the random vibration reponse characteristics of the integrated airborne aid unit on ambulance helicopter,the finite element model of the unit was built by using ANSYS software.According to the vibration characteristics of the airborne platform of the ambulance helicopter,the randomly superimposed sinusoidal excitation spectrum of the airborne broadband was converted into a pure random vibration spectrum useable directly for ANSYS.The natural frequencies and modals of the unit were obtained by modal analysis.On this basis,the converted vibration spectrum was exerted so that the dynamic response and the critical frequencies in different positions of the integrated airborne aid unit were derived by the random vibration analysis.Meanwhile,the dynamic strength of the unit structure was checked up.The result of the analysis has provided a reference for anti-vibration design of the integrated airborne aid unit.