  Many studies have examined the damage behaviour of dual-phase steels already.
It is a topic of high interest, since understanding the mechanisms of damage
during forming processes enables the production of steels with improved
properties and damage tolerance. However, the focus was rarely on the
comparison between representatives of this steel class, and the numerical
simulation for the quantification of damage states was not thoroughly used.
Therefore, this study compares the damage initiation and accumulation of two
dual-phase steels (DP800 and DP1000), which are used in the automotive
industry. Additionally, parameter sets of a phenomenological damage mechanics
model with coupled damage evolution are calibrated for each material. The
combined analysis reveals an earlier initiation of damage for the DP800, where
the damage accumulation phase is prolonged. For DP1000 the damage nucleates
only shortly before material failure. The material model is able to correctly
predict the behaviour, while experimental analysis confirms the prediction via
light optical and SEM metallography.
