INITIAL COLLAPSE OF BRACED ELLIPTIC TUBES UNDER LATERAL COMPRESSION

The initial collapse behavior of elliptical tubes subjected to lateral compression is investigated. Both unbraced and braced tubes are analy sed, and the main factors which affect the initial collapse behavior a re discussed and interpreted. Lower and upper bound theorems are appli ed to bracket the collapse load in a direct manner. The initial collap se loads for braced circular tubes, obtained as a special case of elli ptical tubes, are compared to previous research results. The results a nd concepts presented herein can be useful in the development of desig n criteria for energy dissipating devices. Elliptical shapes, when loa ded parallel to their major axes, can have an advantage over their cir cular counterparts in that they possess larger collapse strokes and an increased energy dissipation potential per unit mass. (C) 1997 Elsevi er Science Ltd.