The collapse of tubes under axial load is an important subject from the safety point of view, particularly in the design of energy absorbing devices used in many engineering applications. In this study, quasi-static and dynamic experiments were carried out on square thin-walled aluminum extrusions to investigate the effects of circular holes. Cutouts were introduced in the four corners of the square-section tube, not far from the end boundary of the tube, in order both to decrease the first peak load on the load-displacement characteristic and to control the collapse mode. Different aspects, such as the buckling modes and the energy absorption in quasi-static axial crushing tests, as well as dynamic effects and material rheology contributions in dynamic crushing tests, have been examined. For the dynamic tests, the parameters were the impacting mass and its velocity. The results showed a drop in the first peak function of the openings’ radius and the tube’s energy absorption capacity was kept. A comparison between static and dynamic tests results was carried out and the interpretation of the results in terms of deformation mechanism and energy absorption was discussed. Numerical simulations with the finite element code ABAQUS were conducted to confirm the experimental findings. The results of different numerical models, implicit and explicit calculations, that contribute to a basic understanding of the buckling and prediction of the crash behavior of the aluminum components without and with the cutouts are presented.