An experimental method for determining ductile tearing energy of thin metal sheets

Abstract

This paper presents a few typical experimental methods for determining the value of tearing energy under a simple plane stress condition and proposes a novel one for it. In this method, several unixaial tensile tests were conducted with test specimens of various lengths. It was assumed that, for each test, the total energy required to tear the specimen can be decomposed into two parts: one associated with tearing (including the plastic deformation in the vicinity of torn cross section) and the other with the plastic deformation over the whole working volume of the specimen. Consequently, when plotting the total energy divided by the specimen width and thickness against the working length of the specimen, a straight line was obtained. The intercept of this line gives the value of tearing energy, corresponding to a zero length specimen. For mild steel, this value was found to be 1520 kJ/m². Comparisons were made between the present result and those by other test methods.