多重激励下机匣振动能量传递规律与耦合特性

Investigation on Transmitting Regularities and Coupling Characteristics of Vibrational Energy for Casing Structure under Multiple Excitations

为了研究机匣振动能量的传递规律和转子多重不平衡激励能量在机匣上的耦合特性,采用有限元法建立了包括压气机机匣、燃烧室机匣和涡轮机匣组件在内的航空发动机整机机匣模型,应用结构声强法计算分析了机匣在不同激励频率下振动能量的传递规律和耦合特性。结果表明:(1)机匣共振时,振动能量的穿透力最强,主要以纵波和剪切波的形式穿过机匣安装边向其他部件传递。(2)机匣的模态振型与其振动能量传递特性有关,振动幅值较大的机匣组件同时也是主要参与振动能量传递的机匣组件。(3)振动能量在机匣上的传递具有解耦特性,多重激励同时作用下的机匣振动能量传递特性可以分解为多个单一激励作用下机匣振动能量的线性矢量和。

To study the transmitting regularities and coupling characteristics of the vibrational energy forcasing under multiple unbalance excitations,a whole casing structure,containing compressor casing,combustorcasing and turbine casing,was established utilizing finite element method,and the transmitting regularities andcoupling characteristics of the vibrational energy of the casing were calculated and analyzed under different loadfrequencies utilizing structural intensity method.Following conclusion can be summarized:(1)the vibrational en-ergy is carried by longitudinal energy wave and shear energy wave passing through the casing flanges to other cas-ing components with the strongest penetrating capacity when the casing is resonating.(2)The mode shape of thecasing is related to the transmitting regularities of the vibrational energy.The casing component with larger vibra-tion amplitudes is also the main casing component for vibrational energy transmission.(3)The transmission ofthe vibrational energy can be decoupled in the casing.Therefore,the transmission properties of the vibrational en-ergy of the casing under multiple excitations at the same time can be obtained by the linear superposition for vibrational energy of the casing under multiple single excitation.The method and conclusions of this paper can apply tocasing vibration attenuation.