Effects of cold roll dimpling process on mechanical properties of dimpled steel.

Abstract

In this paper, the effect of a dimpling process on the mechanical properties of the steel material was studied experimentally and numerically. Nano-hardness and tensile tests of steel samples prior to and after the dimpling process were conducted to evaluate the effects of the process on the mechanical properties. Numerical simulations of the dimpling process and tensile tests were done by Finite Element Analysis; they were used to quantify the amount of non-uniform plastic strains and residual stresses introduced and the manner, in which this was distributed through the sheet. The cold roll dimpling process resulted in developing the plastic strain and residual stress which could correlate to the modifications in the strength and stiffness of the dimpled steel when compared to plain steel originating from the same coil material. The simulation of the dimpling process and tensile tests of the plain and dimpled specimens predicted similar behaviour to the experimental measurements and tests.