Research Information System
3rd International Iron and Steel Symposium, Karabük, Turkey, 3 - 05 April 2017, pp.74-78
Hydroforming has been increasingly exploited by
automotive industry due to several advantages such as more
homogeneous deformation of workpiece, uniform thickness
distribution, better surface properties due to lack of forming tool
– workpiece contact interaction, etc. Advanced High Strength
Steels (AHSS), on the other hand, have unique properties that
make them prominent near-future solution in lightweighting, and
improved safety efforts for auto industry. Current study, is aimed
for investigating the hydroformability of DP 600, DP 800, and
TRIP 780 advanced high strength steel (AHSS) grades at room
temperature. To this goal, FEA of hydroforming process was
modeled in which AHSS sheets were hydroformed into a closed die
cavity with a non-axisymmetric geometry. 3D FE model of
hydroforming process was established and validated with
commercial FEA package Ls-Dyna. Process parameters (e.g.
hydroforming pressure, blank holder force, etc.) were optimized
using Ls-Opt, an artificial neural network (ANN) based
optimization module integrated into Ls-Dyna, to compare the
formability of AHSS steels. Thickness reduction (TR) of formed
sheets and die cavity filling ratio (CFR) were taken as control
parameters. Optimum hydroformability was obtained with the
combination of 800 kN blank holder force and 25 MPa hydraulic
pressure. Moreover, DP 600 has shown the highest
hydroformability when TR and CFR values were compared.