A Niknejad - Mechanical Engineering Department, Faculty of Engineering, Yasouj University, Yasouj, Iran
G. H. Liaghat - Mechanical Engineering Department, Faculty of Engineering, Tarbiat Modares University, Tehran, Iran
Ali Elahi - Mechanical Engineering Department, Faculty of Engineering, Yasouj University, Yasouj, Iran

In this article, six geometrical groups of brazen circular tubes are used in the lateral compression tests in two conditions: empty and polyurethane foam-filled. Energy absorption capacity of different specimens is measured and diagram of absorbed energy versus the lateral displacement are sketched during the flattening process, based on the lateral compression tests. The curves show that increasing in the lateral displacement and the tube wall thickness causes the increasing in the absorbed energy. Comparison of the lateral load-displacement diagrams of empty and foam-filled tubes results that polyurethane foam-filler increase the energy absorption capacity of structure. Also, a semi empirical relation derived to predict the specific energy absorption by the empty tubes under the lateral load. According to the introduced relation, if the mean diameter of tube redoubles, the specific absorbed energy would multiply to 3.58. Also, if the wall thickness of tube redoubles, the specific energy absorption would multiply to 2.24. Therefore, the increasing in the tube diameter is preferred to the increasing in the wall thickness, based on the energy absorption capability.

Circular tube; Energy absorption; Flattening; Lateral compression; Polyurethane foam