Fiber Element Model of Sandwich Panels with Soft Cores and Composite Skins in Bending Considering Large Shear Deformations and Localized Skin Wrinkling
Publication: Journal of Engineering Mechanics
Volume 142, Issue 5
Abstract
This paper studies the flexural performance of sandwich panels composed of a soft polyurethane foam core and glass-fiber-reinforced polymer (GFRP) skins. A robust numerical model is developed to predict the full load-deflection and strain responses of the panel. It is based on equilibrium and strain compatibility and accounts for the excessive shear deformation and material nonlinearity of the core. It also accounts for geometric nonlinearity in the form of localized deflection of the loaded skin using the principals of beam-on-elastic foundation and the change in core thickness due to its softness. The model incorporates various failure criteria, namely core shear failure, core flexural tension or compression failure, compression skin crushing or wrinkling, or tensile rupture of skin. The model has the advantage of being able to isolate quantitatively the individual contributions of flexure, shear, and localized skin deformations, to overall deflection. A parametric study is performed to examine the effects of core density and skin thickness on panel behavior. It is shown that as the core density increases from 32 to , the contribution of shear to overall deflection reduces from about 90 to 10%. It also appears that the optimal core density of the sandwich panels is within 96 to , which represents the lowest density necessary to achieve the highest ultimate strength and stiffness.
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Published In
Journal of Engineering Mechanics
Volume 142 • Issue 5 • May 2016
Copyright
© 2016 American Society of Civil Engineers.
History
Received: Dec 13, 2014
Accepted: Nov 24, 2015
Published online: Jan 28, 2016
Published in print: May 1, 2016
Discussion open until: Jun 28, 2016
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