Effect of Triggering Mechanism on the Load-Displacement Response and Folding Pattern of Square Aluminum Tubes

A systematic numerical investigation of the effect of triggering mechanism on the load-displacement characteristics and lobe formation of square aluminum tubes subjected to quasi-static axial compressive load is presented. Among the physical triggering mechanisms considered were chamfering, drilled holes, geometric imperfection and combinations thereof. The effect of corner radius was also considered. This study has shown that the triggering mechanism controls the load-displacement response as well as the folding pattern. Even though the folding initiation force varies significantly with triggering mechanism, the mean load does not vary greatly. The load- displacement response does not depend appreciably on the corner radius; however, the folding initiation force is lower when a rounded corner is used instead of sharp corners. The folding pattern is also influenced by the corner radius.