The study of structural instability plays a role of primary importance in the field of applied mechanics. Despite the remarkable progresses made in the recent past years, the structural instability remains one of the most challenging topics in applied - chanics. Many problems have bee:: solved in the last decades but still many others remain to be solved satisfactorily. The increasing number of papers published in jo- nals and conferences organized by ECCS, SSRC, IUTAM, and EUROMECH strongly indicates the interest of scientists and engineers in the subject. A careful examination of these...