LINEARIZED MECHANICAL MODEL TO EVALUATE RELIABILITY OF OFFSHORE STRUCTURES

In this paper, an efficient reliability method is proposed for space f ramed structures. It is based on linearization of the mechanical behav iour. The elastic-plastic behaviour of material is piecewise linearize d by a plastic criterion taking into account the interaction of intern al forces. The buckling effect is represented by using an equivalent n egative strain-hardening, introduced to the material model. In order t o identify the negative strain-hardening parameters, a powerful method is given. The proposed model also takes into account the unloading of members and the behaviour at criterion singular points. The structura l reliability is estimated by the safety margin concepts. Numerical ex amples show the high performance of the model, verified by a good prec ision and a very tow computational time.