Elastic stability and post-buckling behavior of circular rings partially supported on rigid saddles

Abstract

This paper presents a numerical study on the nonlinear elastic response of a circular ring in bilateralcontact with a rigid cradle. The analysis focuses on geometric nonlinearities associated with large displacementswhile assuming linear elastic material behavior. The formulation employs an incremental-iterative approach basedon the corotational description, implemented using the general-purpose software MASTAN2 and the in-housecode CS-ASA, enabling cross-validation of results. Several geometric and loading parameters, including ringslenderness, saddle geometry, and support stiffness, are examined to characterize the load-displacement behaviorand the evolution of the contact region. The results highlight the influence of boundary conditions on the stabilityand post-buckling response, emphasizing the changes in stiffness due to the contact constraint. The close agreementbetween both computational tools confirms the reliability of the adopted modeling strategy. The study contributesto a better understanding of nonlinear elastic interactions between curved members and rigid supports, providinginsights relevant to structural and mechanical systems involving ring- or arch-like components.