Defect sensitivity in dynamic plastic response and failure of 1D structures

Engineering structures usually contain defects such as cracks, notches, holes and voids. Engineering practice indicates that when a structure suffers impact load arising from working environment or accidents, these defects absorb a significant portion of the work done by the dynamic load, which alters the dynamic response and failure features of the structure. To quantify the effect of the defects, this paper proposes and elaborates a novel concept, "defect sensitivity function", from the viewpoint of energy dissipation. Case studies are then given to demonstrate the defect sensitivity function in various types of cracked or notched 1D structural members, such as a cantilever beam, circular ring, simply supported beam and free-free beam, including reference to relevant experimental observations. It is found that a "defect sensitive region" exists for each case. From these cases, fundamental features of the defect sensitivity function are explored. (C) 2000 Elsevier Science Ltd. All rights reserved.