Determination of ductile damage parameters by notched plate tensile test using image analysis

摘要

A determination method was proposed for deciding material properties relating to ductile fracturenlimit (damage parameters) through a tensile test. Gradual changes in a necking shape of thentensile test specimens were measured by a notched plate tensile test using image analysis. Usingnthe tensile test, strain and stress changes at the necking along various deformation paths werenobtained. Critical damage values of integrated ductile fracture equations were estimated, andnthey changed depending on initial notch radius and aspect ratio of plate tensile testpiece.nFurthermore, stress triaxiality and equivalent strain change were measured to investigate theninfluence of aspect ratio of width and thickness of testpiece on equivalent strain at final failure. Itnwas found that ductility of steel decreases with the decrease in the aspect ratio.