RELIABILITY ANALYSIS OF METAL FATIGUE PROBLEMS BY MEANS OF THE PROBABILISTIC FINITE ELEMENT METHOD:APPLICATION TO AUTOMOTIVE COMPONENTS

摘要

In the current paper a new model for random life prediction in the crackinitiation phase is presented, using for that probabilistic finite elements (PFEM) and Bmodels, developed by Bogdanoff and Kozin. These B models, usual in the treatment ofcumulative damage processes, have been used in the fatigue field just using experimentaldata. However, these models have been built up in the current work by means of numericalresults, obtained using probabilistic finite element calculations. For doing that, a 'thick plate'probabilistic finite element has been implemented, based on the Reissner-Mindlin theory andusing the perturbation approach, including all the formulation as a user subroutine of thecommercial software ABAQUS. Random variables considered in the current work are YoungModulus, thickness and extemal loads.The expressions used for life prediction are those proposed by Rambert-Osgood, Neuber,Coffin, Basquin and Manson, including in its formulation the consideration of randomvariables (cyclic material properties). All these developments have been applied to a realautomotive braking component, with the aim of checking the influence of differentmanufacturing tolerances in the reliability of the product.