Bending of sandwich beams with transversely flexible core

On the free vibration of sandwich panels with a transversely flexible and temperature-dependent core material – Part I: Mathematical formulation

“…Hence, the distributions of the accelerations through the depth of the core are assumed to follow the distributions of the static displacements under fully distributed loads, see Frostig et al (1992). This approach is commonly used in many dynamic analyses of ordinary beams, plates and shells, see Shames and Dym (1973).…”

“…A different approach that models the sandwich panel as a layered structure made of two face sheets and a core layer that are interconnected through fulfillment of equilibrium and compatibility conditions, and thus accounts for the vertical core flexibility, has been implemented into the so-called High-Order Sandwich Panel Theory (HSAPT), see Frostig et al (1992). It has been successfully used In this two parts paper, the dynamic governing equations, including rotary inertia and the required boundary conditions are derived explicitly using the Hamilton's principle.…”

“…This is denoted as a mixed formulation, and according to this approach the stress and the displacements fields of the non-uniform core are derived in the form of a closed-form solution using a least-square curve-fitting procedure. The second model assumes that the distribution of the in-plane and vertical core displacements can be represented as cubic and quadratic polynomials, respectively, following the results of the HSAPT model (for core displacements see Frostig et al (1992)). The unknowns in this model consist of the displacements of the face sheets and the coefficients of the polynomials in the core.…”

Flexure of beams with an interlayer: symmetric beams with orthotropic adherends

“…Use of the simplest possible formulation that can capture the global bending behavior allows us to obtain a closed form solution. The approach shares several elements with the layer-wise approach developed for sandwich beams with a flexible core by Frostig and Baruch [1990], although they considered a thick core between thin faces and addressed local indentation at load introduction and support regions, while the main focus of our approach is on the global beam response and shear transfer effects. Alfredsson [2004] examined adhesively bonded end-notch flexure (ENF) fracture test specimens, but his analysis is valid only for infinitely thin layers.…”

Material characteristics of 3-D FRP sandwich panels

“…They assume that the height of the beam remains unchanged and that the longitudinal displacement through the depth of the beam is expressed by a high-order polynomial with coefficients that are functions of the longitudinal coordinate and are determined by the boundary and the overall equilibrium conditions of the section. Frostig and Baruch [10] and Frostig et al [11] studied the behavior of a uniform sandwich beam with identical and non-identical skins and a soft core using a superposition approach that determines the effects of the core flexibility on the stresses, on the deflections, and on the overall beam behavior. An enhanced highorder theory was developed for beams using a superposition method.…”