A piecewise parabolic function of involute spline couplings axial modification was presented

and the modified geometric model of involute spline couplings was built.Based on the finite element method

the fretting frictional contact property of typical involute spline couplings was analyzed

and the contact stress and relative slip distributions of modified and unmodified involute spline couplings were obtained

as well as the effects of modified position and modified quantity on contact characteristics of modified involute spline couplings were considered.The following conclusions can be drawn from the analysis results.The piecewise parabolic function meets the axial modification requirement of involute spline couplings

and the modification curve is smooth.Axial modification can effectively reduce phenomena of concentrated contact stress and relative slip for involute spline.Modified positions should be the ends and latter half of external spline in the typical model.Modification quantity of the ends should be a reasonable choice for the model

and modification quantity of the back is generally larger than that of the front.