TRANSITION FROM LOCAL TO GLOBAL BUCKLING: QUASI-STATIC AND DYNAMIC EXPERIMENTAL RESULTS

摘要

In order to study the transition between progressive and global buckling of axially loaded aluminium extrusions, quasi-static and dynamic tests on thin-walled aluminium extrusions were carried out. The primary variables in the tests were the local and global slenderness of the extruded members. The critical global slenderness is defined as the slenderness where a transition from a stable progressive local folding to a global buckling mode occurs. In the quasi-static tests the critical global slenderness was found to be an increasing function of the slenderness of the cross sectional elements. In contrast, the critical global slenderness was a decreasing function of the local slenderness when the impact velocity was 20 m/s. The overall response was found to be very dependent on the location of the first lobes.