![]() |
Computational & Technology Resources
an online resource for computational,
engineering & technology publications |
|
Civil-Comp Proceedings
ISSN 1759-3433 CCP: 75
PROCEEDINGS OF THE SIXTH INTERNATIONAL CONFERENCE ON COMPUTATIONAL STRUCTURES TECHNOLOGY Edited by: B.H.V. Topping and Z. Bittnar
Paper 83
Prediction of the Two-Scale Buckling Response of Sandwich Beams under In-Plane Compression L. Léotoing, S. Drapier and A. Vautrin
Mechanical and Materials Engineering Department - SMS Division, École Nationale Supérieure des Mines de Saint-Étienne, France Full Bibliographic Reference for this paper
, "Prediction of the Two-Scale Buckling Response of Sandwich Beams under In-Plane Compression", in B.H.V. Topping, Z. Bittnar, (Editors), "Proceedings of the Sixth International Conference on Computational Structures Technology", Civil-Comp Press, Stirlingshire, UK, Paper 83, 2002. doi:10.4203/ccp.75.83
Keywords: buckling, sandwich, interaction, localization, plasticity.
Summary
Sandwich structures exhibit a high specific flexural stiffness but also a complex
mechanical behaviour. This last particularity is emphasized when inplane compression
is considered. Indeed, geometrical instabilities can appear at the global scale of the
structure or at the local scale of the components (core and skins). The aim of this work
is to model analytically and numerically the global and local buckling of a sandwich
beam, but also the possible interactions between instabilities at these two scales.
First, an analytical beam model based on a high order theory is established,
which permits to isolate simple critical loads (Equations (83.1))
associated with global buckling of
the beam (
Thanks to the analysis of the sign of the difference between these three critical loads,
design diagrams (Figure 83.1) are built which are useful to quickly identify sandwich beam
configurations locally
Then, a "simplified" non-conform FE model (beam elements for the skins and bi-dimensional
elements for the core) is built and assessed which permits to find a good correlation
between the numerical and the previous analytical critical loads and wavelengths. The
low timeconsuming calculation of this model leads to an efficient characterization of
the complete response of the sandwich beam in a material and/or geometrical nonlinear
framework. The stability of the different buckling forms are discussed, as well as the
high sensitivity towards global or local geometrical imperfections. In order to model the
actual behaviour of crushing foams, an elastoplastic constitutive law (yield stress
purchase the full-text of this paper (price £20)
go to the previous paper |
||