Prediction of fretting damage and wear fatigue of floating involute spline couplings

浮动渐开线花键微动损伤及磨损疲劳预测

School of Mechanical Engineering, Northwestern Polytechnical University, Xi’an 710072, China

Received: 18 July 2021

Abstract

In this paper, a finite element model of the floating spline pair is first established, and the distribution of the contact pressure on the tooth surface of the spline with the axis and angular misalignment is analyzed. Then, the effects of axial misalignment and angular eccentricity on tooth fretting damage were evaluated, based on Ruiz fretting damage parameters. Finally, a floating spline wear fatigue damage model considering the wear effect is established based on the energy dissipation and critical plane SWT model, and the fretting fatigue cumulative damage distribution and life of the tooth surface under axial and angular misalignment are analyzed and evaluated. The results show that the misalignment of the axis makes the contact pressure distribution of each tooth uneven, and the R_FFDP value of the most dangerous tooth is parabolic along the x direction, that is, serious fretting damage may occur at both ends of the tooth surface, and the crack initiation position on the tooth occurs near x/L=0. The angular misalignment makes the tooth contact only at one end edge, and the R_FFDP value of the most dangerous tooth increases along the x direction, showing an exponential growth trend, reaching the maximum at x/L=1, and the crack initiation position occurs at near x/L=1. With the increase of axis or angular misalignment, the damage phenomenon of the floating spline tooth surface becomes more obvious, and the wear-fatigue life decreases sharply.

摘要

通过建立浮动花键副有限元模型, 分析了轴线不对中和角向偏心对花键齿面接触压力的分布影响, 基于Ruiz微动损伤参数评估了轴线不对中和角向偏心对齿面微动损伤的影响, 结合能量耗散模型和临界面SWT模型, 建立了考虑磨损效应的浮动花键磨损疲劳损伤模型, 分析了轴线不对中和角向偏心下齿面的微动疲劳累积损伤分布规律, 并预测了浮动花键寿命。结果表明, 轴线不对中使各齿面接触分布不均, 最危险齿面沿x方向R_FFDP值呈现"抛物线"状, 即在齿面两端产生较为严重的微动损伤, 且齿面裂纹萌生位置在x/L=0处附近。角向偏心使齿面仅在一端边缘接触, 最危险齿面R_FFDP值均沿x方向增大, 呈现"指数增长"趋势, 在x/L=1处达到最大, 且裂纹萌生位置发生在x/L=1处附近。同时, 随着轴线不对中或角向偏心量的增大, 齿面损伤现象更为明显, 磨损疲劳寿命急剧下降。