Simplified Nonlinear Model of Straight-Sheathed Wood Diaphragms in Unreinforced Masonry Buildings
Publication: Journal of Structural Engineering
Volume 146, Issue 4
Abstract
A simplified nonlinear numerical model is proposed to predict the full dynamic response of straight-sheathed wood diaphragms in unreinforced masonry buildings. The straight-sheathing system is replaced with an equivalent Bernoulli beam element at the center of the diaphragm and parallel to the joists. Nonlinear rotational springs are used to simulate the moment couple generated by nail pairs at the wood-board-to-joist connections. The reduced multidegree of freedom model is able to capture the distributed properties of the diaphragm and maintain compatible out-of-plane displacements with supporting masonry walls. The versatility of the model is demonstrated through implementation in the research software OpenSees and commercial software SAP2000 to conduct modal, cyclic, quasi-static, and nonlinear response history analyses. Comparison to previously proposed numerical models for wood diaphragms including detailed finite element models and experimental results from the literature indicates that the reduced multidegree of freedom model accurately predicts the seismic response of wood diaphragms with computational efficiency. Finally, the reduced multidegree of freedom model is implemented within the numerical model of a large unreinforced masonry building to demonstrate its practical use and integration with masonry walls.
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Data Availability Statement
Some or all data, models, or code generated or used during the study are available from the corresponding author by request (Sap2000 and OpenSees models of the wood diaphragm).
Acknowledgments
The research described in this paper was supported by the Multidisciplinary Center for Earthquake Engineering Research (MCEER), which provided financial support to the first author. Any opinions, findings, conclusions or recommendations expressed in this paper are those of the authors and do not necessarily reflect the views of the MCEER. The authors would also like to thank Dr. David Peralta for providing the experimental data conducted in wood diaphragms for the MAE program.
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Published In
Journal of Structural Engineering
Volume 146 • Issue 4 • April 2020
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©2020 American Society of Civil Engineers.
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Received: Dec 11, 2018
Accepted: Jul 30, 2019
Published online: Jan 22, 2020
Published in print: Apr 1, 2020
Discussion open until: Jun 22, 2020
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