DIRECT DETERMINATION OF LIMITING CYCLE DURING CYCLIC LOADING

A general framework for the modelling of mechanical behavior of struct ures has been recently proposed by J. Zarka et al. Its essential featu re consists of the introduction of a group of internal parameters whic h characterize the local inelastic mechanisms of the structure, and a group of transformed internal parameters which are linearly linked to the previous ones through a symmetrical non-negative matrix. With this approach, the treatment of the local plastic yield conditions can be made easily from simple elastic analysis. The problem of the determina tion of the limit state in the case of cyclic loading is then reduced to the determination of the asymptotic values of the transformed inter nal parameters. In most cases, this is done by simple geometrical cons tructions. As an example, we will present a simple structure made of t wo connected elastoplastic workhardening cylinders of different radius , subjected to cyclic imposed displacement at one end, in order to sho w the efficiency of the method.