Thesis
Effects of Simulated Decay in Perforated Light-Frame Wood Shear Walls
Washington State University
Master of Science (MS), Washington State University
2021
DOI:
https://doi.org/10.7273/000005541
Abstract
Light frame wood structures are a very popular choice for homeowners and builders alike. These structures implement shear walls, often with openings, designed by structural engineers based on local wind and seismic risk to resist the lateral loads and transfer them to the foundation. When these structures are built in regions such as the Pacific Northwest where there exist conditions conducive to fungal growth which include: suitably mild temperatures, moisture, and oxygen (USDA, 2010), the structure is at a higher risk for fungal decay to occur if the building envelope is compromised, especially around openings. This experimental research aims to test full scale shear walls with and without simulated decay to analyze the effect it has, and compare the results to a numerical model, i.e. M-CASHEW2, to better understand the effects decay has on the capacity of shear walls, as well as understand if a numerical model can be used to determine the residual capacity of shear walls in the field affected with decay. This will be accomplished by testing two groups of walls, control and decay, using two sheathing nailing schedules. To simulate decay in the decay group of walls, sheathing nails were omitted in three pre-determined zones below the perforation. After testing it was found that, shear walls with simulated decay and 6/12 or 4/12 nail schedule had a decrease in capacity of 33.4% and 25.8% respectively while the same walls experienced a decrease in initial stiffness of 40.8% and 32.6% respectively. Additionally, the M-CASHEW2 models for both the control and partially decayed groups was able to predict average maximum lateral loads within 9% of measured results for all shear wall groups, with varying accuracy of the displacements at which the maximum lateral forces would occur. M-CASHEW2 also predicted a smaller decrease in initial stiffness from the control group to partially decayed for both 6/12 and 4/12 walls, measuring a 27.6% and 12% decrease respectively. Overall, M-CASHEW2 shows promise in modeling shear walls with simulated advanced decay, but more experiments need to be conducted to prove its accuracy with different locations and degrees of decay.
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Details
- Title
- Effects of Simulated Decay in Perforated Light-Frame Wood Shear Walls
- Creators
- Jakob Sheehan
- Contributors
- Donald A Bender (Advisor)James D Dolan (Committee Member)Adam R Phillips (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Department of Civil and Environmental Engineering
- Theses and Dissertations
- Master of Science (MS), Washington State University
- Publisher
- Washington State University
- Number of pages
- 145
- Identifiers
- 99901052237601842
- Language
- English
- Resource Type
- Thesis