Modeling System Effects and Structural Load Paths in a Wood-Framed Structure
Publication: Journal of Architectural Engineering
Volume 17, Issue 4
Abstract
The objective of this project was to evaluate system effects and further define load paths within a light-frame wood structure under extreme wind events. The three-dimensional 30- by 40-ft (9.1- by 12.2-m) building, designed to be representative of typical light-frame wood construction in the southeastern coastal region of the United States, was modeled using SAP2000. Wall and roof sheathing was modeled using SAP’s built-in thick shell element. The effect of edge nail spacing of the wall sheathing was incorporated by way of a novel correlation procedure, which eliminated the need to represent each nail individually. The computer model was validated against both two- and three-dimensional experimental studies (in plane and out of plane). Uniform uplift pressure, worst-case simulated hurricane, and ASCE 7-05 pressures were applied to the roof, and vertical foundation reactions were evaluated. The ASCE 7-05 uplift pressures were found to adequately encompass the range of uplift reactions that can be expected from a severe wind event such as a hurricane. Consequently, it was observed that ASCE 7-05 “component and cladding” pressures satisfactorily captured the building’s uplift response at the foundation level without the use of “main wind force-resisting system” loads. Additionally, the manner in which the walls of the structure distribute roof-level loads to the foundation depends on the edge nailing of the wall sheathing. It was also revealed that an opening in any wall results in a loss of load-carrying capacity for the entire wall. Moreover, the wall opposite the one with the opening can also be significantly affected depending on the orientation of the trusses. In general, it was determined that complex, three-dimensional building responses can be adequately characterized using the practical and effective modeling procedures developed in this study. The same modeling process can be readily applied in industry for similar light-framed wood structures.
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Acknowledgments
Funding provided by NSF (Award No. NSFCMMI 0800023) and USDA Center for Wood Utilization research grant is greatly appreciated.
References
American Forest and Paper Association (AF&PA). (2001). “Wood frame construction manual.” ANSI/AF&PA WFMC-2001, Washington, DC.
American Forest and Paper Association (AF&PA). (2005a). “National design specification for wood construction.” ANSI/AF&PA NDS-2005, Washington, DC.
American Forest and Paper Association (AF&PA). (2005b). “Special design provisions for wind and seismic.” ANSI/AF&PA SDPWS-2005, Washington, DC.
American Forest and Paper Association (AF&PA). (2007). “Connection design.” DES110, Washington, DC.
ASCE. (2005). “Minimum design loads for buildings and other structures.” ASCE/SEI 7-05, New York.
Asiz, A., Chui, C. Y., Smith, I., and Bartlett, M. (2010a). “Full-scale destructive test on wood lightframe structures.” World Conf. on Timber Engineering (CD-ROM), CNR-IVALSA, Trees and Timber Institute, Florence, Italy.
Asiz, A., Chui, C. Y., Zhou, L., and Smith, I. (2010b). “Three-dimensional numerical model of progressive failure in wood light-frame buildings.” World Conf. on Timber Engineering (CD-ROM), Riva del Garda, Italy.
Computers and Structures, Inc. (2008). CSI Analysis Reference Manual: SAP2000, ETABS and SAFE, Berkeley, CA.
Datin, P. L., and Prevatt, D. O. (2007). “Wind uplift reactions at roof-to-wall connections of wood-framed gable roof assembly.” 12th Int. Wind Engineering Conf., Australasian Wind Engineering Society, Cairns, Australia.
Dikkers, R. D., Marshall, R. D., and Thom, H. C. S. (1970). Hurricane Camille—August 1969: A survey of structural damage along the Mississippi Gulf Coast, National Bureau of Standards, Washington, DC.
Doudak, G. (2005). “Field determination and modeling of load paths in wood light-frame structures.” Ph.D. thesis, McGill Univ., Montreal, Quebec, Canada.
FEMA. (2006). Hurricane Katrina in the Gulf Coast: Mitigation assessment team report—Building performance observations, recommendations, and technical guidance, Washington, DC.
Gupta, R. (2005). “System behavior of wood truss assemblies.” Prog. Struct. Eng. Mater., 7(4), 183–193.
Gupta, R., and Limkatanyoo, P. (2008). “Practical approach to designing wood roof truss assemblies.” Pract. Period. Struct. Des. Constr., 13(3), 135–146.
Gupta, R., Miller, T. H., and Dung, D. (2004). “Practical solution to wood truss assembly design problems.” Pract. Period. Struct. Des. Constr., 9(1), 54–60.
Hill, K. M., Datin, P. L., and Prevatt, D. O. (2009). “Revisiting wind uplift testing of wood roof sheathing—Interpretation of static and dynamic test results.” Hurricane Hugo 20th Anniversary Symp. on Building Safer Communities—Improving Disaster Resilience, Applied Technology Council, Redwood City, CA.
Kasal, B. (1992). “A nonlinear three-dimensional finite-element model of a light-frame structure.” Ph.D. thesis, Oregon State Univ., Corvallis, OR.
LaFave, K. D., and Itani, R. Y. (1992). “Comprehensive load distribution model for wood truss roof assemblies.” Wood Fiber Sci., 24(1), 79–88.
Langlois, J., Gupta, R., and Miller, T. H. (2004). “Effects of reference displacement and damage accumulation in wood shear walls.” J. Struct. Eng., 130(3), 470–479.
Lebeda, D., Gupta, R., Rosowsky, D., and Dolan, J. D. (2005). “The effect of hold-down misplacement on the strength and stiffness of wood shear walls.” Pract. Period. Struct. Des. Constr., 10(2), 79–87.
Li, Z., Gupta, R., and Miller, T. H. (1998). “Practical approach to modeling of wood truss roof assemblies.” Pract. Period. Struct. Des. Constr., 3(3), 119–124.
Martin, K. G. (2010). “Evaluation of system effects and structural load paths in a wood-frame building.” M.S. thesis, Oregon State Univ., Corvallis, OR, 〈http://ir.library.oregonstate.edu/jspui/handle/1957/14312〉.
McCutcheon, W. J. (1977). “Method for predicting the stiffness of wood-joist floor systems with partial composite action.” FPL-RP-289, Forest Products Laboratory, Madison, WI.
Mtenga, P. V. (1991). “Reliability of light-frame wood roof systems.” Ph.D. thesis, Univ. of Wisconsin—Madison, Madison, WI.
Percival, D. H., and Comus, Q. B. (1980). “Load distribution in a full-scale nailed-glued hip-roof system.” For. Prod. J., 30(11), 17–21.
Reed, T. D., Rosowsky, D. V., and Schiff, S. D. (1997). “Uplift capacity of light-frame rafter to top plate connections.” J. Archit. Eng., 3(4), 156–163.
Riley, M. A., and Sadek, F. (2003). Experimental testing of roof to wall connections in wood frame houses, National Institute of Standards and Technology, Gaithersburg, MD.
Seaders, P. (2004). “Performance of partially and fully anchored wood frame shear walls under monotonic, cyclic, and earthquake loads.” M.S. thesis, Oregon State Univ., Corvallis, OR.
Seaders, P., Gupta, R., and Miller, T. H. (2009). “Monotonic and cyclic load testing of partially and fully-anchored wood-frame shear walls.” Wood Fiber Sci., 41(2), 145–156.
Simpson Strong-Tie Company, Inc. (2008). “Wood construction connectors.” C-2009 Product Catalog, Pleasanton, CA.
Sinha, A., and Gupta, R. (2009). “Strain distribution in OSB and GWB in wood-frame shear walls.” J. Struct. Eng., 135(6), 666–675.
Sutt, E. G., Jr. (2000). “The effect of combined shear and uplift forces on roof sheathing panels.” Ph.D. dissertation, Clemson Univ., Clemson, SC.
Taly, N. (2003). Loads and load paths in buildings: Principles of structural design, International Code Council, Inc., Washington, DC.
USDA. (1999). “Wood handbook: Wood as an engineering material.” USDA Forest Service FPL-GTR-113, Forest Products Laboratory, Madison, WI.
van de Lindt, J. W., Graettinger, A., Gupta, R., Skaggs, T., Pryor, S., and Fridley, K. (2007). “Performance of woodframe structures during Hurricane Katrina.” J. Perform. Constr. Facil., 21(2), 108–116.
Wolfe, R. W., and LaBissoniere, T. (1991). “Structural performance of light-frame roof assemblies II. Conventional truss assemblies.” FPL-RP-499, Forest Products Laboratory, Madison, WI.
Wolfe, R. W., and McCarthy, M. (1989). “Structural performance of light-frame roof assemblies: I. Truss assemblies with high truss stiffness variability.” FPL-RP-492, Forest Products Laboratory, Madison, WI.
Wolfe, R. W., Percival, D. H., and Moody, R. C. (1986). “Strength and stiffness of light framed sloped trusses.” FPL-RP-471, Forest Products Laboratory, Madison, WI.
Zisis, I. (2006). “Structural monitoring and wind tunnel studies of a low wooden building.” M.S. thesis, Concordia Univ., Montreal, Canada.
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© 2011 American Society of Civil Engineers.
History
Received: Feb 25, 2010
Accepted: May 19, 2011
Published online: Nov 15, 2011
Published in print: Dec 1, 2011
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