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

Abstract

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

Keywords:

• Ductile fracture
• Plastic deformation limit
• Tensile test
• Image analysis
• Stress triaxiality