Critical static loads calculations in finite element method of three-layered annular plates

This paper presents the results of critical, static loads calculations of three-layered, annular plates with a soft core. The plate with slidably clamped edges, uniformly loaded with compressive stress on the inner edges of outer layers and of the symmetric cross-section structure is the subject of consideration. In the description of deformation of layers, the assumption of the equal deflections of plate layers has or has not been used. The calculations were carried out for several plate models built of finite elements using the system ABAQUS. The analysis of the distribution of values of critical loads, depending on various thicknesses of plate core, different values of facing thicknesses and on two kinds of core foam material of different stiffnesses, indicates some essential results, which are important in the plate stability problems. Among them the observation of possible area of too high values of critical loads shows the limitation of usage of rather universally applied assumption of equal layers deflections in cross-section deformation of the plates with thick core. This conclusion seems to be particularly important for designers.