Determination of stress-strain relationship of sheet metal under biaxial tension

Abstract

This paper demonstrates that the biaxial stress-strain relationship of sheet metal may be determined from the hydraulic bulge test with values for stress and strain being calculated from local curvature measurements. It is also shown that the workhardening characteristics may be derived for stress ratios other than those in equibiaxial tension. This need arises from the fact that the critical section of a sheet metal product is frequently subjected to stress and strain paths other than uniaxial or equibiaxial tension.