Probability density functions (normal, lognormal, and three-parameter Weibull) were used to characterize strength data for three different types of metal-plate-connected wood truss joints (web at the bottom chord, tension splice, and heel). Modulus of elasticity (MOE) of the lumber used to fabricate the joints was also characterized. A probability-plot technique,...
It is commonly accepted in the analysis of wood beams that the neutral axis coincides with the beam's centroid. However, wood is not an isotropic material, has different elastic properties in the tangential, radial and longitudinal directions, and is non-homogeneous, as it contains characteristics such as knots. Therefore, there is...
This paper presents the results of a test program whose goal was to better understand the contribution of individual elements to the performance of typical light-frame wood structures during tsunami loading. The intent was to be able to replicate failures in a structural engineering laboratory that were observed during laboratory...
There are about 80 million single-family dwellings (SFDs) in the United States, predominantly of wood-frame construction. Of these, 68% are owner-occupied. A home is typically the largest single investment of a family, and is often not covered by earthquake insurance, even where it is available. Of all the houses in...
The objective of this study was to develop and validate practical modeling methods for investigating load paths and system behavior in a realistic, light-frame wood structure. The modeling methods were validated against full-scale tests on sub-assemblies and an L-shaped house. The model of the L-shaped house was then modified and...
This study evaluated the effects of pretreatment incising of dry lumber and preservative treatment on the shear strength of 1980 pieces of 2 X 4 dimension lumber (nominal 50 mm X 100 mm X 3.6 m long). Three species groups (Douglas-fir, Hem-Fir. and Spruce-Pine-Fir-South) and two commercially produced machine-stress-rated grades...
Tsunamis have devastated coastal regions worldwide, with the most recent being the result of the Great Tohoku Japan earthquake and tsunami, which was a M9.0 undersea megathrust earthquake that occurred off the east coast of Japan on March 11, 2011. In this study, a fragility formulation is utilized to develop...
Ten full-size (3.7×4.9m) plywood roof diaphragms were constructed using metal-plate-connected (MPC) common and hip wood trusses or joists, typical of single-family dwelling (SFD) construction. The specimens included three gable roof slopes of 33, 67, and 100%, a hip roof of 33% slope, and a flat roof, with a horizontal bottom...
Residential energy use is a significant contributor to greenhouse gas emissions and climate change. Reducing energy efficiency in conventional wood-framed houses are thermal bridges: direct paths that allow heat to flow through the studs instead of the insulation. One suggestion for reducing thermal bridging is the staggered stud (SS) wall....
Goals of this preliminary study are to better understand (1) earthquake performance of wood-frame shear walls carrying gravity loads, compared with walls without gravity load, and (2) performance of walls subjected to a sequence of earthquake motions, compared with walls subjected to a single earthquake.
Tests with simulated earthquake ground...
The forces exerted on light-frame wood buildings as a result of surge and waves are not fully understood. With a better understanding of these types of forces, it may eventually be possible to build coastal structures to better withstand the loads. In this paper, a recent two part experimental study...
Compression perpendicular to grain (C┴) of wood is an important property and has a drastic effect on serviceability of the structure. Typical C┴ loading scenarios include the bottom chord of a truss resting on the top plate of a shear wall and chords of a shear wall resting on the...
Ten full size (3.7 x 4.9 m) plywood roof diaphragms were constructed using metal plate connected (MPC) common and hip wood trusses or joists, typical of single-family dwelling (SFD) construction. The specimens included three gable roof slopes of 33, 67 and 100%, a hip roof of 33% slope, and a...
The objective of this study was to compare structural load path and system behavior of a light-frame (LF) and a timber frame (TF) structure. This load path analysis is part of a broader research effort that compares LF to TF residential structures. Structural analysis software was used to create a...
There are about 80 million single-family dwellings (SFD) in the United States,
predominantly of wood-frame construction. Of these, 68% are owner occupied. A home is
typically the largest single investment of a family, and is often not covered by earthquake
insurance, even where it is available. Of all the houses...
Earthquake performance of wood-frame shear walls was evaluated by comparing fully and partially anchored walls under monotonic, cyclic, and earthquake loads and comparing with code measures. Suitability of monotonic and cyclic testing to predict seismic performance was examined. Earthquake tests were conducted on 2440-mm-square walls with Douglas-fir studs. Two oriented...
The objective of this study was to develop and validate practical modeling methods for investigating load paths and system behavior in a realistic light-frame wood structure. The modeling methods were validated against full-scale tests on subassemblies and an L-shaped house. The model of the L-shaped house was then modified and...
Seismic design of wood-frame single-family dwellings’ (WFSFD) lateral force–resisting systems requires determination of the stiffness of horizontal diaphragms and shearwalls. During design, sizes and locations of shearwall openings are often changed, altering shearwall stiffness and loads and requiring a significant redesign effort. Rigid and tributary area method analyses are examined...
Current compression perpendicular-to-grain (C⊥) design values for wood members are based on mean stress obtained from ASTM D143 specimen. The standard ASTM test with metal on wood bearing has limited applicability in modern construction assemblies with C⊥ loading scenarios. Previous work has shown that end-bearing conditions and wood-on-wood C⊥ bearing...
Current compression perpendicular-to-grain (C-perpendicular to) design values for wood members are based on mean stress obtained from ASTM D143 specimen. The standard ASTM test with metal on wood bearing has limited applicability in modern construction assemblies with C-perpendicular to loading scenarios. Previous work has shown that end-bearing conditions and wood-on-wood...