GENERAL BUCKLING ANALYSIS OF SANDWICH CONSTRUCTIONS

General buckling analysis of composite sandwich constructions is treat ed in this paper. Two modes of buckling exist in an elastic structure under certain loading cases, that is, bifurcation point buckling and e xtreme point buckling. This paper is concerned with bifurcation point buckling. The energy criterion is used for deriving the theoretical fo rmulae. According to the energy criterion, the positive two-order vari ation of the general potential energy, pi, for an elastic mechanics sy stem is necessary and sufficient condition to ensure a stable static b alance state. The sandwich construction would not support loads and wo uld suffer failure if general instability occurred on it. In the gener al buckling analysis, the formulae are based on the finite element met hod of linearity theory. The critical stress control equations corresp onding to the bifurcation point buckling can be obtained by commanding two-order variation of the general potential energy, pi, to equal zer o. The critical load corresponding to structural general instability c an be given by solving the generalized eigenvalue problem. It is shown by four numerical examples that the calculated results and accuracy a re satisfied under a set of computation equations derived in this pape r.