Analysis of Contact Stress and Deformation in a Trilobe Polygonal Connection

Abstract

A numerical method for determination of contact stress and deformation in a multilobe connection of shafts and hubs is presented. It relies upon NASTRAN for computation of surface deflections of both members which are then matched by means of relative rotation. Several examples of stress distribution in a trilobe connection and the effects of torque and internal clearance upon maximum pressure, extent of contact, its location and torsional compliance are given. Results discredit the application of well-known Hertzian formulas to this closely conformal non-Hertzian contact and suggest a surprisingly simple approximation. This is the first published solution to the problem of contact in a trilobe connection.