Initial collapse of braced elliptical tubes under lateral compression

The initial collapse behavior of elliptical tubes subjected to lateral compression is investigated. Both unbraced and braced tubes are analysed, and the main factors which affect the initial collapse behavior are discussed and interpreted. Lower and upper bound theorems are applied to bracket the collapse load in a direct manner. The initial collapse loads for braced circular tubes, obtained as a special case of elliptical tubes, are compared to previous research results. The results and concepts presented herein can be useful in the development of design criteria for energy dissipating devices. Elliptical shapes, when loaded parallel to their major axes, can have an advantage over their circular counterparts in that they possess larger collapse strokes and an increased energy dissipation potential per unit mass.