Advancing contact between a rigid pin and a FGM circular beam with clearance

The progressive and frictionless contact problem between a rigid circular pin and a circular beam with a uniform cross-section made of elastic functionally graded material (FGM) is investigated under clearance-fit conditions. The stress and displacement fields in the FGM circular beam are taken from the general solution for plane elastic problems involving FGMs in polar coordinates, analogous to Mitchell’s solution for homogeneous isotropic materials. The frictionless contact conditions yield a set of dual series equations similar to those obtained for a homogeneous and isotropic elastic circular beam, then reduced to a linear system of infinite equations, which is solved by truncation. By assuming discrete values of the contact angle, the corresponding stress and displacement fields within the lug are derived and, in turn, the resultant load acting on the rigid pin is assessed. The new analytical results are then validated against finite element predictions and a satisfactory agreement is observed for typical geometries and various material grading parameters. The present findings can assist mechanical engineers in optimally designing innovative pinned connections and improving their load-bearing capacity by exploiting the advantages of FGMs.