Wind load sharing and vertical load transfer from roof to wall in a timber-framed house

Satheeskumar, Navaratnam (2016) Wind load sharing and vertical load transfer from roof to wall in a timber-framed house. PhD thesis, James Cook University.

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Abstract

Windstorms are one of the major causes of severe damage to houses and other infrastructure. Damage investigations indicate that the roof is the most vulnerable part of a timber-framed house, and that failures take place at inter component connections; hence there is a need to study the load sharing and structural response of these timber-framed house structural systems to assess their performance. Contemporary houses in many parts of Australia are brick veneer structures with metal or tile clad roofs that are built to National Construction Code of Australia's design specifications.

Full-scale tests were carried out on a representative part of a brick veneer contemporary house to assess the loading effects on roof to wall connections and load sharing. Tests were conducted for each stage of construction: bare frame followed by the installation of roof battens and cladding, wall lining, ceiling, etc. These construction stages were used to assess the contribution of the structural and lining (i.e. ceiling, ceiling cornice and wall lining) elements to the load sharing and response of the timber-framed house structure to wind loading. Results show that the vertical load sharing of the timber-framed house through the roof to wall connection depends on the stiffness of the roof to wall connection and the truss location (i.e. whether located at the end or middle). The contribution of the lining elements to the vertical load sharing is about 15% to 20%.

In addition, individual component tests were conducted on the roof to wall framing anchor (i.e. triple grip and truss grip) connections to examine their structural response to loading. This study also showed that construction defects in roof to wall connections influence the design uplift capacity. Two missing nails out of ten in the hand nailed triple grip connection (i.e. one nail from the truss and other one from the top plate) reduces the design uplift capacity by about 40 % of the "Ideal" hand nailed triple grip connection. Finite element models were also developed for part of the timber framed house and roof to wall connections (i.e. triple grip and truss grip connections) using ABAQUS finite element software. Results obtained from the finite element models were compared with the experimental tests, showing good agreement. This finite element model can be used to predict the roof to wall connection response and truss hold-down force variation with a range of construction defects and truss bay configurations. The overall outcomes can be used to evaluate house structure vulnerability to wind loading, and to improve the design and standards of timber-framed houses.

Item ID: 49793
Item Type: Thesis (PhD)
Keywords: finite element model, finite-element modeling, full-scale test, load sharing, roof to wall connection, structural response, timber-frame houses, timber-framed structure, uplift capacity, vertical load, wind effects, wind load, wind pressure, wooden-frame houses
Additional Information:

Publications arising from this thesis are available from the Related URLs field. The publications are:

Satheeskumar, N., Henderson, D.J., Ginger, J.D., and Wang, C.H. (2016) Wind uplift strength capacity variation in roof-to-wall connections of timber-framed houses. Journal of Architectural Engineering, 22 (2).

Satheeskumar, N., Henderson, D.J., Ginger, J.D., Humphreys, M.T., and Wang, C.H. (2016) Load sharing and structural response of roof-wall system in a timber-framed house. Engineering Structures, 122. pp. 310-322.

Satheeskumar, N., Henderson, D.J., Ginger, J.D., and Wang, C.H. (2017) Finite element modelling of the structural response of roof to wall framing connections in timber-framed houses. Engineering Structures, 134. pp. 25-36.

Satheeskumar, Navaratnam, Henderson, David James, Ginger, John David, and Wang, Chi-Hsiang (2017) Three-dimensional finite-element modeling and validation of a timber-framed house to wind loading. Journal of Structural Engineering, 143 (9). pp. 1-11.

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Date Deposited: 10 Aug 2017 01:49
FoR Codes: 09 ENGINEERING > 0905 Civil Engineering > 090506 Structural Engineering @ 80%
09 ENGINEERING > 0905 Civil Engineering > 090502 Construction Engineering @ 20%
SEO Codes: 86 MANUFACTURING > 8612 Fabricated Metal Products > 861206 Structural Metal Products @ 40%
86 MANUFACTURING > 8612 Fabricated Metal Products > 861205 Sheet Metal Products @ 40%
86 MANUFACTURING > 8612 Fabricated Metal Products > 861201 Coated Metal and Metal-Coated Products @ 20%
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