INTRODUCTION TO COMPUTATIONAL MODELS OF DAMAGE DYNAMICS UNDER STOCHASTIC ACTIONS

This paper reviews and discusses some basic ingredients necessary for the study of damaged continua with diffused defects like microcracks, pores, dislocations, etc., under stochastic loading histories and, in particular, under sequences of impulses described by Poisson arrival p rocesses. The mechanical model of a continuum with microstructure is a dopted: in other words, the state of the continuum is described by the usual displacement field and by an additional field of a second-order non-symmetric tensor which describes the microstructural rearrangemen t of the material due to the presence of defects. It is shown that the time evolution of this tensor, usually assumed empirically on the bas is of experimental results, is governed by a balance equation. The dis cretization of the problem and integral measures of damage, useful for the numerical solutions, are also discussed.