Static Modeling of Plywood–Polyurethane Structural Insulated Panels in Bending
Publication: Journal of Structural Engineering
Volume 147, Issue 2
Abstract
Structural insulated panels (SIPs) are thermally efficient, prefabricated structural elements that expedite on-site construction with a minimal number of skilled workers. This research aimed to model the time-independent mechanical response of transversely loaded SIPs with plywood skins and a closed-cell rigid polyurethane foam core. The foam core was characterized in both shear and compression through experimental testing, and a trilinear strain-based constitutive model was found suitable for the shear, while a linear response was adequate for compression. Two models, one analytical the other numerical, were produced using the component behavior and validated by comparison to the results of full-scale SIPs experimentally tested in quarter-point bending at two spans, 2.40 and 3.65 m. The analytical model is based on thin-faced, antiplane-core sandwich beam theory, while the numerical model is a two-dimensional plane-strain finite-element model (FEM). Good agreement was found between the analytical model and full-scale bending tests. However, it was found that the experimentally observed polyurethane shear moduli had to be reduced to 77% of their original values to provide good agreement of the FEM with the full-scale bending tests. While both models accurately predicted the bending deflection of the panels, neither was able to satisfactorily predict ultimate strength.
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Data Availability Statement
Some or all data, models, or code that support the findings of this study are available from the corresponding author upon reasonable request.
Acknowledgments
The authors express their gratitude for the generous SIP donations by Ron Burkhardsmeir of Alaska Insulated Panels. This material is based on work supported by the National Science Foundation Graduate Research Fellowship under Grant No. 1313666. This project was made possible by funds donated by Ted and Gloria Trueblood through the University of Alaska Anchorage, along with the UAA College of Engineering, for which the authors express sincere gratitude.
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Information & Authors
Information
Published In
Journal of Structural Engineering
Volume 147 • Issue 2 • February 2021
Copyright
© 2020 American Society of Civil Engineers.
History
Received: Jan 17, 2020
Accepted: Sep 14, 2020
Published online: Nov 30, 2020
Published in print: Feb 1, 2021
Discussion open until: Apr 30, 2021
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