Experimental and Numerical Characterization of Monotonic and Cyclic Performance of Cross-Laminated Timber Dowel-Type Connections
Publication: Journal of Structural Engineering
Volume 147, Issue 7
Abstract
An immeasurable amount of greenhouse gas emissions during the process of steel purification and concrete production has attracted environmentally friendly engineers’ attention to extend and enhance the use of wood as a structural material. During the last two decades, cross-laminated timber (CLT) has emerged as a high-strength engineered wood product to improve resistance and performance of timber structures, and is being used as a replacement for some mid and low-rise commercial buildings made of concrete and steel in the US. Due to the fact that CLT is a relatively new engineered wood product, there is a lack of knowledge on the mechanical behavior of CLT members and connections. The goal of the present study is to characterize the mechanical properties (specifically shear resistance) of three common types of CLT diaphragm connections including surface spline, half lap, and butt joint, and estimate the behavior of those connections in ultimate limit states, such as earthquake loads, and also serviceability limit states. In doing so, an experimental schedule was developed for a total of 56 tests accounting for different test variables including fastener orientation, type, length, and spacing. More specifically, two types of dowel-type fasteners, namely nail and screw, were considered, while the effect of fastener spacing and inclination was considered by changing the spacing of nails and driven angle of screws. The exerted force and displacement were recorded generating hysteresis curves to assess the failure mechanisms, shear modulus of elasticity, ultimate allowable shear strength and displacement, and energy dissipation of the various connections studied. A finite-element model based on elastoplastic behavior of CLT for a half-lap connection was also developed to estimate the shear behavior of this type of connection numerically and compare it with the experimental findings. Finally, the experimental results were used to compute the optimized hysteretic parameters (and their statistics) for the CUREE-SAWS hysteretic model for further adoption in modeling of diaphragm components by practicing engineers and researchers.
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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 material presented in this paper is based on work supported in part by the US Department of Agriculture (USDA) Forest Services and the US Endowment for Forestry and Communities Grant No. E17-96. Any opinions, findings, conclusions, and recommendations presented in this paper are those of the authors and do not necessarily reflect the views of the USDA and the US Endowment for Forestry and Communities. The authors would also like to acknowledge the contributions of Nicholas Lucia (undergraduate student, Texas A&M University) and Gustavo Rodriguez Zuniga (exchange student at Texas A&M University from Pontificia Universidad Catolica De Chile in Santiago, Chile) during the testing preparation and execution. The contributions and suggestions of Bibek Bhardwaj (graduate student, Clemson University) are also greatly appreciated. The finite-element analyses were conducted at the Texas A&M’s High Performance Research Computing Center. This support is gratefully acknowledged.
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Published In
Journal of Structural Engineering
Volume 147 • Issue 7 • July 2021
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© 2021 American Society of Civil Engineers.
History
Received: Jun 4, 2020
Accepted: Feb 25, 2021
Published online: May 6, 2021
Published in print: Jul 1, 2021
Discussion open until: Oct 6, 2021
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