An Experimental Approach to Evaluate the Critical Damage

Abstract

An experimental study has been carried out to determine the critical damage parameter based on the concept of entropy flow. The fatigue damage is either a cumulative process that progresses toward a maximum tolerable damage, or is an irreversible progression of cyclic plastic strain energy that reaches its critical value at the onset of fracture. In the present study, irreversible heat dissipation in terms of entropy is utilized to experimentally determine the degradation of different specimens subjected to low cyclic bending fatigue. An experimental correlation between entropy and damage is proposed. It is shown that the cyclic energy dissipation in the form of thermodynamic entropy can be effectively utilized to determine the critical damage value.