We are interested in sandwich beams whose skin may be
thick (as defined by H. G.
Allen) and whose core stiffness along the sandwich longitudinal axis may be large
enough to influence the deflection (that is, we also account for nonantiplane
sandwiches), whereas the core is such that it is allowed to disregard its deformability
along its height (the direction of the applied load). For such sandwiches we are
particularly interested in investigating the reliability of simple models, such as
the first-order shear deformation models, for accurate computation of the
deflection in the linear elastic range. We therefore compare different theories on
the basis of finite element simulations and focus on the case of a propped
cantilever beam supporting a uniform load. In fact, this boundary value problem
leads to slightly different conclusions than those previously drawn based on
statically determinate cases, such as in three-point bending. The analysis
suggests that known models may be largely inaccurate in predicting sandwich
behaviour under bending and shear, depending on a peculiarity of the actual
sandwich kinematics indirectly describing the interaction between skins and core,
in turn due both to material and geometrical properties and to boundary
conditions.
