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This work deals with the prediction of the fatigue crack growth of bonded joints. Traditionally cohesive zone model is used for the simulation of failure of bonded joint under quasi-static and impact conditions. On the other hand fracture mechanics concepts are used for the prediction of fatigue crack growth in bonded joint. In this work a modified cohesive damage model, accounting for the fatigue crack growth, was implemented in the commercial software ABAQUS. The fatigue damage evolution in the cohesive element is related to the number of cycles through the experimental fatigue crack growth behavior. An automated procedure, valid for any from the geometry and load distribution, was also defined to compute the Strain Energy Release Rate, the necessary input to define the instantaneous fatigue crack growth rate. The model is validated by comparing the simulation to fatigue crack growth tests. [ABSTRACT FROM AUTHOR]

The problem of fatigue characterization of materials by small data samples is here considered and a Bayesian procedure for data analysis is presented. For both hot rolled and quenched and tempered carbon steels, on the basis of some literature data and by well-established correlations between fatigue and tensile properties, a prior probability density function, able to model most of the available information on material fatigue strength, is defined. Prior information, when fused by means of Bayes theorem with information from experimental data, allows to identify with greater accuracy the fatigue properties of the tested steel A Montecarlo study is carded out to verify the effectiveness of the proposed method, generating small samples of fatigue data by virtual testing. [ABSTRACT FROM AUTHOR]