EXPERIMENTAL INVESTIGATION ON RESPONSES OF ALUMINUM BEAMS TO LOW VELOCITY IMPACTS

For beams under transverse impacts, the influences of the projectile's mass and velocity, impact position and target stiffness, on the dynamic responses and impact effects of beams, such as impact force, global deformation and local deformation, is fundamental in anti-impact structural design. Six aluminum beams were transversely impacted by a low-velocity impact machine herein. Influences of parameters (i.e., velocity, impact position and specimen stiffness) on dynamic responses (i.e., impact force, global and local deformation, strain and energy) of beams were analyzed. The results revealed:with an increasing impact velocity, the specimen's energy absorption speed and impact force amplitude increased, but the peak value duration of impact load reduced; both global and local deformation increased, but the increase in the local effects was more significant; with an increasing specimen stiffness (i.e., thickness), energy absorption speed and the peak value of impact force increased under the same impact velocity; the global deformation decreased while the local deformation increased, indicating that with an increasing stiffness, the global effect was weakened while the local effect was enhanced; compared with the impact force, the global deformation was obviously lagged, indicating that the global effect was lagged behind the local effect.