Steel flexural yielding arms can be an effective energy dissipation device for several seismic force resisting systems, including controlled rocking masonry walls. In controlled rocking masonry walls, uplift of the wall from the foundation is allowed in a way that can localize damage and minimize post-earthquake residual drifts. However, along with other modes of failure, sliding of the rocking walls can increase drifts and damage if not adequately addressed. Controlled rocking systems have different alternatives to prevent sliding, which include the use of additional mechanical components (e.g. metal stoppers) at the corners to resist lateral forces while allowing the wall rocking motion. However, these mechanical components hinder the constructability of the wall in some cases. The use of an energy dissipation device (i.e. steel flexural yielding arm) to also prevent the wall sliding mechanism has not been fully explored to date. The development of an easily replaceable energy dissipation device with the ability to simultaneously resist sliding demands is expected to maintain the overall performance of controlled rocking masonry walls, while also enhancing post-earthquake repairability.
The objective of the current study is to experimentally investigate the effect of axial forces on the behaviour of steel flexural yielding arms under cyclic loading. In this respect, the study first presents a description of the experimental program, test setup, and instrumentation. Next, the experimental results of the tested specimens are discussed in terms of the effect of axial forces on the load, displacement, and energy dissipation capacities of the tested devices. Finally, new design equations that account for axial forces are proposed and verified against the experimental data along with a finite element model. Based on the results, recommendations are given for the further development of externally attached and replaceable flexural yielding arms for controlled rocking masonry walls. / Thesis / Master of Applied Science (MASc) / Controlled rocking masonry walls can be a cost-efficient alternative to traditional masonry shear walls because of their enhanced performance, specifically to reduce and localize structural damage induced by seismic loads. However, a controlled rocking wall requires additional energy dissipation devices or post-tensioning techniques to compliment the rocking wall to achieve the desired performance.
This thesis explores and improves a type of energy dissipation device for controlled rocking masonry walls and aims to provide detailed design specifications for professional engineers. A design and considerations from previous studies are discussed, followed by the experimental validation, and finally new design equations are proposed for this type of reliable, flexural energy dissipation device.
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/24969 |
| Date | January 2019 |
| Creators | Li, Jeff (Jie Fei) |
| Contributors | Wiebe, Lydell, Ezzeldin, Mohamed, Civil Engineering |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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