In-Plane Bending and Failure Mechanism of Sandwich Beams with GFRP Skins and Soft Polyurethane Foam Core
Publication: Journal of Composites for Construction
Volume 20, Issue 1
Abstract
The out-of-plane bending of sandwich panels has been widely investigated, but studies on their behavior under in-plane loading are quite scarce. In this study, 18 sandwich beam specimens were tested under three- and four-point in-plane-bending. The specimens are composed of low-density polyurethane core and glass fiber-reinforced polymer (GFRP) skins on both sides. The shear span-to-depth () ratio was varied from 1.33 to 4.67. Two different skin thicknesses were also used, providing beam depth-to-skin thickness () ratios of 47 and 94. It was found that the ultimate moment reduced by approximately one third as the ratio increased from 1.33 to 4.67 in sandwich beams with an ratio of 94 and decreased by about one quarter in beams with an ratio of 47. Doubling the skin thickness [i.e., from of 94–47] increased the moment capacity significantly. The percentage increase ranged from 55 to 95% as increased from 1.33 to 4.67. Failure of sandwich beams occurred by skin wrinkling in compression, mostly symmetrically, where skins move in opposite directions. A simplified analytical model accounting for shear and flexural rigidities of the sandwich beam and a skin wrinkling failure criterion in compression was developed and validated against experimental results.
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Acknowledgments
The authors wish to acknowledge the financial support provided by the Natural Sciences and Engineering Research Council of Canada (NSERC). The authors are also thankful to undergraduate student Matt Farrel for his contributions to the experimental component of this research.
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© 2015 American Society of Civil Engineers.
History
Received: Oct 8, 2014
Accepted: Feb 17, 2015
Published online: May 5, 2015
Discussion open until: Oct 5, 2015
Published in print: Feb 1, 2016
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