Effect of aging treatment on bending collapse and energy absorption of 7003 aluminum alloy bumper beams

• Under-aged 7003 aluminum alloy bumper beams exhibit optimal energy absorption (7.86 kJ) and high peak force (38.75 kN) under three-point bending. • Peak bending force is proportional to material strength across different aging conditions, while stress triaxiality governs cracking failure. • Pre-aged and under-aged beams resist cracking up to 250 mm displacement due to a stress transition from tensile to compressive on the bottom surface. • The Swift−Hockett−Sherby constitutive model combined with the Gurson−Tvergaard−Needleman damage model accurately predicts plastic response and fracture behavior.