Behavior and failure modes of low-rise wood-framed buildings subjected to seismic and wind forces.

摘要

The objective of this study was to understand the three-dimensional behavior of low-rise wood-framed buildings and to identify their modes of failure where subjected to seismic and wind forces. Analytical closed-form solutions of shear walls, from the consideration of equations of equilibrium with and without uplift, were developed and compared with the results from the finite element-type computer program HOUSE verified against the available test results. The bending effect of the frames and intermediate studs was also studied. The effect of stud-sole plate joint stiffness, the vertical load and the number of panels on the uplift were investigated in detail. Ductility analysis was conducted for the different shear walls and connection nail force-slip curves. Buckling and direct shear failure of the sheathing panel were investigated for the various boundary conditions, and, then, interaction diagrams of the failure modes were obtained.; Based on these analyses, the modes of failure of full-scale house were investigated after some modifications of the computer program HOUSE by identifying all the possible failures of the elements. To show the applicability of this study, three examples of three-dimensional full-scale house models, the Tuomi and McCutcheon model, and the Goers' Model Houses A and B were analyzed. Using the Tuomi-McCutcheon model, we investigated the effect of the uplift force. Using the Goers' Model House A, we examined the effect of the nail spacing at the sole and the sill plate. Also we conducted a parametric study of the sheathing nail stiffness. Interior kitchen walls were included in the analysis, and the effect on the behavior of the whole house was investigated.; A new scheme, the distributed nail stiffness method, was introduced. Then, the behavior of shear walls of linear and nonlinear systems was investigated using this method, and the error was examined. Shear walls with uplifting were also analyzed. A finite element-type nonlinear computer program N-HOUSE was developed using this method to analyze three-dimensional buildings. The computer program N-HOUSE was verified using the Tuomi and McCutcheon test house and the Washington State test house. Then, Goers' Model Houses A and B were analyzed using this computer program. The effectiveness and accuracy of this method were shown, especially for the nonlinear analysis. Then, the modes of failure of Goers' Model Houses A and B were identified by using this nonlinear computer program.