PUBLICATIONS
Published works
The structural response and progressive failure of batten to rafter connections under wind loads
Title | The structural response and progressive failure of batten to rafter connections under wind loads |
Publication Type | Thesis |
Year of Publication | 2018 |
Authors | Parackal, K |
Date Published | 12/2018 |
University | James Cook University |
City | Brisbane |
Keywords | batten to rafter, Correlation of loads, Light framed structures, Low-rise buildings, progressive failures, wind engineering, wind loads, Wind tunnel study |
Abstract | Batten to rafter connections in light framed timber housing are vulnerable to wind loading and failures of these connections are one of the more common failure modes seen in post windstorm damage surveys. Such failures often occur in a progressive or cascading manner resulting in the loss of a large section of the building envelope. These progressive failures of batten to rafter connections are a complex process influenced by the pressure fluctuations on the roof surface, the response of individual connections and the behaviour of the structural system as a whole. This study presents a method of examining load redistribution and progressive failure behaviour of batten to rafter connections in light framed structures. Nonlinear time history analysis was performed using a finite element model using fluctuating pressures determined from a wind tunnel study and connection properties determined from laboratory testing of connections under dynamic loads. Flow separation and building-induced turbulence cause intermittent ‘peak-events’ where negative pressures on the roof surface are especially high. These 'peak-events' can move across the roof causing high loads occurring at different connections with slight lead or lag times. Damage to connections occur during the 'peak events' as nails are incrementally withdrawn. Loads are redistributed and load paths change during nail slips, causing damage to spread from an initial location. Load redistribution continues until a few connections fail completely, upon which a cascading failure occurs where almost all connections on the roof fail in rapid succession. As an application of this research, the analyses performed were used to assess the fragility of batten-rafter failures, and the most vulnerable parts of the roof identified. Cost effective retrofitting measures can be justified and designed with this information. |
URL | https://researchonline.jcu.edu.au/62277/ |