High-order bending of piecewise uniform sandwich beams with a tapered transition zone and a transversely flexible core

Abstract High-order bending of a piecewise uniform sandwich beam with a tapered transition zone and a transversely flexible core is presented. The behavior is described through the solutions of a uniform and a tapered sandwich beam in the various regions, interconnected while fulfilling the boundary and the continuity conditions between the regions. The longitudinal and the shear forces in the inclined skin of the tapered region yield concentrated forces at the point where the skin longitudinal layout changes, thus leading to stress concentrations in the form of high peeling and shear stresss at the interface between the skin and core, and to high local bending moment in the skin. This stress concentration emerges whether the external loads are concentrated or distributed and is an inherent part of the structure. However, the level of stresses involved can be controlled through the appropriate design of the transition zone. The characteristic behavior in the transition zone and the design parameters that affect the behavior, are studied through a parametric analysis. The fields and the governing equations of a tapered beam are presented, and the results of the parametric study in terms of shear forces and bending moments in the lower skin and shear and peeling stresses at the lower skin-core interfaces, are presented and discussed.