| With the rapid growth of economy in recent years, the increasing cars ownershiphas brought a series of issues, such as exhaustion of energy, the greenhouse effect,dust and harmful gas emissions, etc. Aimng to save enery and reduce emission, thelightweight of automobile has become one of the effective measures. In present paper,two aluminum alloy bumper beams with a good weight loss as well as a excellentcollision safety performance are designed; one is arc shape, another is mansard shape.According to stiffness of the original steel bumper beam, the section size of thearc-shaped aluminum alloy bumper beam is optimized using LS-OPT and a mediumaltitude beam with two strengthening ribs is designed. The weight of this bumperbeam is2.25kg whose weight is only60.5%of the original steel beam. Thethree-point bending and pendulum impact test is performed and show that thisoptimized beam owns a better stiffness.The impact simulations of three kinds of bumper beams are carried out underdifferent conditions and compared with the actual sled impact test at a speed of20km/h. The results show that: These two aluminum alloy bumper beams both havebetter energy absorption performance under all conditions. The beams deformationresults and the acceleration curves of the actual sled impact test are in good agreementwith the simulated results. Compared with the original steelwork, the arc-shapedaluminum alloy bumper beam’s acceleration curve changes smoothly and has a lowermaximum peak. The mansard aluminum alloy bumper beam appears an obviousinward deflection phenomenon, which may damage water tank and wind guide plate inreal vehicle crash.The vehicle frontal crash test shows that the whole car owns an expecteddeformation, and the dummies suffer no significant damage and their body wellcontact with the airbags. At the same time, the acceleration of B-pillar changessmoothly. It is indicated that the arc-shape aluminum alloy bumper beam can replacethe original steel bumper beam well. |
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