A simple method of analysis of partial slip in shrink-fitted shafts under torsion

A solution method is proposed for the partial slip problem of a shrink-fitted shaft under torsion, that relies on the superposition of axisymmetric, elastically uncoupled problems all solved with FE. First, a problem is solved for the contact pressure induced by the interference coupling alone. In the presence of remotely applied torque, antiplane slip occurs at the indenting edge contact extremity; shear actions at the slip portion of the contact interface may merely be derived by scaling the pressure profile through the friction coefficient. A semi-inverse solution approach is derived, based on the assumed extent for the near-edge slip zone; two linear elastic solutions are parametrically mated to cancel stress singularities at the stick-slip transition point, the first solution concerning the remote torque alone, and the second one addressing the interface slip actions alone. We finally discuss the results for a selection of geometrical ratios, and the viability of simplified approaches based on beam theory.