Bending behavior of sandwich structures with flexible functionally graded core based on high-order sandwich panel theory

Abstract

In this study the problem of a sandwich beam with functionally graded (FG) core is attended with use of higher order sandwich panel theory forcing no pre-determined assumptions setting limits to the displacement and stress fields in the core. Face-sheets are analyzed using classical beam theory and the core is subjected to elasticity formulation. Governing equations and boundary conditions are derived using the principle of virtual displacements and governing equations based on five primary variables are solved using Navier's solution. This method yields nonlinear patterns of displacements in the core and as a result it can manage to present localized effects of the core including the change in the core thickness under the load point which is an improvement on the previous classical and higher order theories. This present theory can handle any type of loadings distributed or concentrated and also any type of boundary conditions even when at the same edge, upper and lower facesheets do not have the same boundary conditions. The solution is compared with present literature for a beam with conventional core. The results indicate positive effects of using FG core to reduce the possibility of delamination of the structure at interfaces between the upper and lower face-sheets and the core.

Analytical and Numerical Investigation of Free Vibration Behavior for Sandwich Plate with Functionally Graded Porous Metal Core

“…Wattanasakulponga and Ungbhakorn (2014) used a combination of linear and nonlinear analysis to study the influence of porosity parameters on the frequency parameters of FGM constrained end beams. Although some studies have been conducted on sandwich structures with FGM cores to evaluate their bending behavior (Tossapanon & Wattanasakulpong, 2017;Meiche et al, 2011;Neves et al, 2013) and flexural strength (Kapuria et al, 2008;Lashkari & Rahmani, 2016), sandwich structures' free vibration and stability issues fabricated by functionally gradient have been studied. However, investigations on the free vibration of FGM structures with porous metal topology are still limited.…”

Predicting fracture mechanisms in synthetic foam sandwiches with multi-layered cores using extended cohesive damage model

“…However, it would not a costeffective way to carry out investigations through experimental work to fully study and optimize the behaviour of sandwiches. On the other hand, previous analytical approaches based on various plate theories such as two and three-dimensional elasticity equations, polynomial equations, classical deflection formulae and third-order zig-zag models were conducted to analyse mechanical behaviour of simple sandwich samples [12,13,18,19], but it is not easy to use them to predict detailed fracture mechanisms at the structural level. Hence, it can be argued that numerical modelling is an efficient and effective approach to predict the behaviour of FGSP.…”

Free vibrations and static analysis of functionally graded sandwich plates with three-dimensional finite elements

“…In most of analytical approaches, through-the-thickness assumptions of two-dimensional (2-D) plate/shell theories such as classic (CPT), first order shear deformation (FSDT) and high order shear deformation (HSDT) theories in conjunction with a given variation of elastic constants along the thickness direction are used to obtain the solution, e.g. [22][23][24][25][26][27] among of the many others. As concluded in [28], the material gradient along the thickness direction leads to complex deformations of the core that require the use at least a HSDT theory.…”