Performance of Bumper System with Aluminum Alloys AA6061 and AA7003 Materials Using Numerical Methods 2016-01-1351
Aluminum alloys are widely used in the transportation because of their high strength-to-weight ratio and outstanding capability in absorbing energy. In this paper, performance of bumper with crash tubes using aluminum alloy AA7003 materials is compared with that of AA6061 and high strength steel (DP800) using numerical methods. Quasi-static test is simulated using the LS-DYNA implicit finite element program. Bumper and crash tubes are included in the finite element model. Symmetric Holes are provided in the crash tubes to initiate crushing. The energy absorbed by bumper and crash tubes are compared. Dynamic simulation is done using LS-Dyna explicit program. True stress-true plastic strain curves at different strain rates from the literature is used in the dynamic simulation of AA7003 material to study the strain rate effects on impact behavior of tubes. The impact mass is represented by RigidWall Planar Moving Force option in LSDYNA. The mass and velocity are assigned to impacting mass using the optional cards. Impact speed is considered as per bumper and vehicle standards including FMVSS208. AA7005 bumper shows superior energy absorbed compared to that of AA6061 and steel bumper.