Open AccessThe effects of shear affected zone on edge crack sensitivity in dual-phase steels
Author(s) -
Niloufar Habibi,
Thorsten Beier,
Helmut Richter,
Markus Könemann,
Sebastian Münstermann
Publication year - 2019
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/651/1/012073
Subject(s) - enhanced data rates for gsm evolution , materials science , finite element method , shear (geology) , dual phase steel , structural engineering , residual , sensitivity (control systems) , computer simulation , residual stress , automotive industry , process (computing) , mechanics , composite material , computer science , engineering , microstructure , physics , telecommunications , algorithm , electronic engineering , operating system , aerospace engineering , martensite
Dual phase steels offer good combination of mechanical properties which is attractive for automotive industry. However, some challenges still remain and suppress using them widely. One of these challenges is the formation of premature cracks at shear-cut edges during the subsequent forming processes, which cannot be predicted by the conventional finite element methods. Therefore, the present study aims to propose a numerical tool to predict edge cracks in DP steel components. In this regard, the hole expansion method was applied as an edge crack detection technique on DP1000 steel sheets. To elaborate the study, parallel finite element simulations were performed as well. The simulation method considered the whole hole piercing process and the following hole expansion test as a one-stroke two-step strategy. The hole piercing process was applied in the first step on the sheet and a hole was cut. The results reveal that this process forms some surface irregularities and applies a special amount of damage at the cut edge, which both could have effects on the edge crack sensitivity. To study these effects, the subsequent hole expansion test was simulated on the manufactured hole. Thus, the effects of both surface irregularities and residual damage from hole piercing process were investigated in different case studies with all possible combinations of these effects. This strategy provides possibilities to numerically separate effects of surface quality and residual damage. The contribution shows on the one hand the experimental investigations and on the other hand deals with the numerical influence analyses.