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

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