The effects of geometric parameters of cylindrical surface centering structures on tooth surface wear in aerospace floating splines

Angular misalignment in aerospace applications induces severe fretting wear at the tooth ends of floating splines, compromising aircraft-engine reliability and service life. This study proposes a cylindrical-surface auxiliary centering structure to mitigate such wear and examines its mechanism and sensitivity to key geometric parameters. A geometric-constraint model incorporating radial and effective side clearances was developed to derive conditions that limit spline deflection. A three-dimensional nonlinear finite element wear model was then used for numerical analysis and parameter sensitivity studies under angular misalignment. Under an angular misalignment of 0.1°, the maximum wear depth along the 19 tooth-width-centreline sampling paths decreased from 1.798 μm for the ordinary spline to 0.984 μm for the 15 mm cylindrical-segment configuration selected from the sensitivity analysis, a reduction of 45.3%. Localised wear on the cylindrical segment reached 1.559 μm, indicating its participation in contact. The parameter study yielded a further reduction in maximum wear depth to 0.82 μm. The design reduces localised tooth-end wear by sharing off-centre loads and limiting spline deflection. These findings provide a theoretical and numerical basis for wear-reduction design in aerospace splines under misaligned loading. A supplementary dynamic screening analysis showed that, under identical numerical conditions, the auxiliary centering structure reduced the root-mean-square x -direction acceleration and dominant spectral amplitude by 24.5% and 51.7%, respectively, without evident low-order harmonic amplification. These numerical results suggest that the proposed structure can reduce localised spline wear without an evident adverse vibration response under the investigated conditions.