碰摩作用下盘片榫连结构接触特性的响应分析

Contact characteristics response analysis of blade-disc dovetail structure under rubbing condition

以某压气机燕尾形榫连结构为研究对象,基于ANSYS有限元软件,建立了盘片的有限元模型.用脉冲力模拟局部碰摩时的碰摩力,分析了两种碰摩情况对榫连结构接触特性的影响,首先分析了侵入量为定值时,不同转速对榫连结构接触特性的影响,接着分析了当转速为定值时,不同侵入量对榫连结构接触特性的影响.研究结果表明:随着转速的升高,榫连结构的最大接触压力和最大接触滑移距离不断的增加,最大接触压力变化规律变得更加复杂,而最大接触滑移距离变化规律逐渐趋于稳定并且最大接触滑移距离之间的变化幅度减小.随着侵入量的增加,榫连结构的最大接触压力以及最大接触滑移距离都会增大,但过大的侵入量将导致最大接触滑移距离发生突变.通过分析不同工况下几个节点接触压力及接触滑移距离的频谱响应,发现碰摩会产生转频的高倍频成分,当转频的倍频成分接近叶片固有频率时会出现倍频幅值放大现象.

Targeting a compressor dovetail structure,the finite element model of bladedisc based on software ANSYS was established.The pulse force was used to simulate the rubbing force under local rubbing condition and the effects of two rubbing conditions on contact characteristics of dovetail structure were analyzed.The first condition involved the influence of different rotating speeds on contact characteristics of dovetail structure when the intrusion was constant.The other condition involved the influence of different intrusions on contact characteristics of dovetail structure when the rotating speed was constant.The results show that the maximum contact pressure and the maximum sliding distance of dovetail structure increase with the rotating speed,the variation law of the maximum contact pressure becomes more complicated,but the variation law of the maximum contact sliding distance becomes gradually steady and the change of amplitude between the maximum contact sliding distance decreases.The maximum contact pressure and the maximum sliding distance of dovetail structure increases with the intrusions,but excessive intrusions will lead to the mutation of the maximum contact sliding distance.By analyzing the spectrums of contact pressure and contact sliding distance under different working conditions,it can be seen that the amplitude of multiple frequencies increase when these multiple frequencies are close to natural frequencies of the blade.