Localized Effects in the Nonlinear Behavior of Sandwich Panels with a Transversely Flexible Core
- 1 January 2005
- journal article
- Published by SAGE Publications in Journal of Sandwich Structures & Materials
- Vol. 7 (1), 53-75
- https://doi.org/10.1177/1099636205046207
Abstract
This paper presents the results of an investigation of the role of localized effects within the geometrically nonlinear domain on structural sandwich panels with a “compliant” core. Special emphasis is focused on the nonlinear response near concentrated loads and stiffened core regions. The adopted nonlinear analysis approach incorporates the effects of the vertical flexibility of the core, and it is based on the approach of the High-order Sandwich Panel Theory (HSAPT). The results demonstrate that the effects of localized loads, when taken into the geometrically nonlinear domain, change the response of the panel from a strength problem controlled by stress constraints into a stability problem with unstable limit point behavior when force-controlled loads are applied. The stability problem emerge as the nonlinear response develops with the formation of a small number of buckling waves in the compressed face sheet in the vicinity of the localized loads. The development of the nonlinear response is demonstrated through the numerical study of three-point bending of a unidirectional sandwich panel with an unstiffened core, and with a core stiffened in the vicinity of the loads, respectively. It is shown, that the change from unstiffened to stiffened core alters the nonlinear response significantly. The nonlinear response is described in terms of deflections and stress resultants in the face sheets, as well as in terms of the interfacial stress components at the upper and lower face–core interfaces. The overall nonlinear response is described through curves of the load versus the extreme absolute values of the aforementioned structural quantities. A very important finding of the study is that stiffening of the core may improve the performance in terms of local stresses to some extent, but at the same time it may lead to undesirable bifurcation-type or semi elastoplastic behavior in some cases.Keywords
This publication has 22 references indexed in Scilit:
- Design of sandwich structures for concentrated loadingComposite Structures, 2001
- Buckling of sandwich panels with a flexible core—high-order theoryInternational Journal of Solids and Structures, 1998
- Localized Load Effects in High-Order Bending of Sandwich Panels with Flexible CoreJournal of Engineering Mechanics, 1996
- Computational Models for Sandwich Panels and ShellsApplied Mechanics Reviews, 1996
- Theoretical and experimental investigation of local bending effects in sandwich platesComposite Structures, 1995
- Analysis of local bending effects in sandwich plates with orthotropic face layers subjected to localised loadsComposite Structures, 1993
- On stress concentration in the bending of sandwich beams with transversely flexible coreComposite Structures, 1993
- High‐Order Buckling Analysis of Sandwich Beams with Transversely Flexible CoreJournal of Engineering Mechanics, 1993
- Behavior of delaminated sandwich beam with transversely flexible core — high order theoryComposite Structures, 1992
- High‐Order Theory for Sandwich‐Beam Behavior with Transversely Flexible CoreJournal of Engineering Mechanics, 1992