MICROMECHANISMS AND A COMPUTATIONAL MODEL OF GROWTH OF LOW-TEMPERATURE CREEP CRACKS IN MATERIALS

摘要

We analyze and synthesize the results of investigations available from the literature on the micromecha-nisms of growth of creep cracks and, on the basis of this analysis, show that these cracks grow mainly by the initiation, increase, and coalescence of pores. This enables us to formulate a computational model for the evaluation of the period of subcritical growth of low-temperature creep cracks in structural materials. As a result, we obtain a kinetic equation of growth of these cracks in the form of dependence of the crack growth rate on the stress intensity factor. Together with the initial and the final conditions, this equation forms a computational model for the evaluation of the period of subcritical growth of low-temperature creep cracks.