Local failure such as hole-edge cracking is often observed in forming advanced high-strength steels
(AHSS). Numerical prediction of this local failure is challenging for simulation engineers to evaluate stamping
and crash performances of materials. Finite element method (FEM) modelling requires additional input data,
“failure criteria” to predict the local failures of material, in addition to the material flow stress data input for
simulation. This paper presents the procedure to develop the hole-edge failure criteria using various formability
tests and to design a component bend test structure to evaluate the hole-edge failures of AHSS structures. A
local-strain-based failure criterion and a stress-triaxiality-based failure criterion were developed and
implemented in a FEM simulation code to predict hole-edge failures in component bend tests. The holes were
prepared using two different methods: mechanical punching and water-jet cutting. In the component bend tests,
the water-jet trimmed hole showed delayed fracture at the hole-edges, while the mechanical punched hole
showed early fracture as the bending angle increased. In comparing the simulation and test results, the loaddisplacement curve, the displacement at the onset of cracking, and the final crack shape/length were used. Both
failure criteria showed good correlations with experimental observations, while the conventional tensile-testbased failure criterion resulted in over-prediction of the local formability of the hole-edge during bending and
stretching. Both failure criteria also enable the numerical model to differentiate between the local formability
limit of mechanical-punched and water-jet-trimmed holes. The stress triaxiality-based criterion also allowed the
prediction of the failure in the bucking area where typical ductile failure is observed. The failure criteria and
static bend test developed here are useful to evaluate the local failure at a structural component level for
automotive crash tests.

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