Finite element analysis and experimental study on fretting wear of different contact surfaces of fir-tree joint

Under extreme load conditions of aircraft engines, the multi-tooth structure of the fir-tree joint can improve power output, but it also causes uneven fretting wear between contact surfaces, threatening reliability. This study analyzes the fretting wear of multi-tooth contact surfaces through experiments and simulations. The experimental results show a progressive wear phenomenon, where the closer the contact surface is to the root of the blade, the less the wear depth. Furthermore, an energy model was constructed and validated to investigate the effects of mean load, stress ratios, and friction coefficient, revealing that relative slip dominates the fretting wear mechanism of different contact surfaces. A multi-tooth rigid displacement superposition model was proposed to illustrate the progressive wear phenomenon of fir-tree joints.