A direct method for ratchet boundary determination

Abstract We propose a direct method to identify the ratchet boundary for an elastoplastic structure subjected to a cyclic loading program. The aim is to find a critical amplification factor to the periodic loading such that the amplified cycle produces impending ratcheting. We base our search on the norm of the ratchet plastic strain as a function of the amplification factor. The devised algorithm drives towards the ratchet boundary by means of successive direct asymptotic solutions. Our strategy produces fast and accurate ratchet boundaries, due to the combined performance of the asymptotic solution module and the main ratchet-limit search algorithm. Analytical and numerical benchmark solutions serve as references to evaluate the accuracy of the procedure. An example includes a multi-parametric loading program. Application of the devised method to a printed circuit heat exchanger turns evident its improved precision and performance when compared to alternative numerical approaches.