- Title
- Experimental and numerical study of structural frames with semi-interlocking masonry (SIM) infill panels
- Creator
- Wang, Zhiyu
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2017
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- Dry stack masonry is built without mortar. These masonry structures have attracted interest in the construction industry because they are easy to build. This potentially improves productivity and lowers costs, compared to traditional mortar-jointed masonry construction. Masonry walls are often used in framed structures as infill panels. To improve the seismic behaviour of these structures, a novel mortarless masonry building system based on semi-interlocking masonry (SIM) has been developed at the Centre for Infrastructure Performance and Reliability, University of Newcastle, Australia. In this system, the SIM units are capable of relative sliding in-plane when constructed as a panel, and locked against relative movement out-of-plane. Compared with traditional unreinforced masonry (URM), SIM can increase earthquake energy dissipation through friction between bricks. Under seismic loads, SIM panels do not detrimentally interfere with natural frame vibration but contribute positively to earthquake resistance, mainly by increasing damping. Therefore, SIM panels can be used in earthquake resistant framed structures as infill panels, and act as energy dissipation devices. In this thesis, an experimental and numerical study was conducted to investigate the nonlinear static and seismic behaviour of SIM infill panels. The results show that SIM infill panels are a viable alternative to traditional URM infill panels in seismically active areas. In the experimental part of the study, in-plane tests were performed on a steel frame with a topological SIM panel to evaluate the structural potential and the cyclic behaviour of the panels. The in-plane force-displacement behaviour of the structure, its stiffness degradation, energy dissipation, and its response mechanisms were studied and compared to the behaviour of the bare frame. The results indicate that the gap between the frame and the top of the panel significantly influences the composite response of the structure. Next, the responses of a steel frame with a topological SIM panel, and an RC frame with a prototype SIM panel were compared in terms of their crack patterns, hysteretic behaviour and energy dissipation. The prototype SIM panels and topological SIM panels had similar hysteretic behaviour, as well as the same energy dissipation mechanisms. They therefore produced similar seismic response capacities. Then, numerical models were developed in SeismoStruct. This program uses the equivalent diagonal strut model for masonry panels. This model was developed for traditional URM panels based on multiple experimental tests. However, conventional compressive struts do not form in SIM panels. SIM panels provide some resistance to diagonal compression and shear but this resistance relates to frictional forces between bricks and the frame. They are physically different to URM panels. No existing models that reflect the actual physical behaviour of SIM panels were located. In the numerical part of this study, the equivalent strut model was used with parameters adjusted to match the available experimental results for SIM. The model was calibrated and verified by comparing these results with those of the bare RC frame, the RC frame infilled with a prototype SIM panel, the RC frame infilled with a traditional URM panel, the bare steel frame and the steel frame with a topological SIM panel. In addition, model calibration and verification was also conducted for the following case studies: multistorey bare RC frame, multistorey RC frame with traditional URM infill panels and multistorey bare steel frame. Finally, numerical simulations were conducted to evaluate the nonlinear static and seismic behaviour of the SIM infill panels on the multistorey bare RC and steel frames, the multistorey frames with SIM panels with a gap between the top of the panels and the frame, the multistorey frames with SIM panels without a gap between the top of the panels and the frame, and the multistorey frames with traditional URM panels. The results show that the RC frame and the steel frame with SIM infill panels have structural properties which, in combination, help them to improve structural ductility and reduce the base shear force during extreme earthquake events. The experimental tests and numerical modelling conducted for this study were based on prototype SIM panels and topological SIM panels. Further research is needed to investigate how mechanical SIM panels with dowels react in out-of-plane tests and numerical models. The current models are limited to two-dimensional analyses of in-plane behaviour of framed structures with SIM infill panels. Three-dimensional models based on the actual observed behaviour of SIM panels need to be developed to capture the actual physical in-plane and out-of-plane behaviour of these panels.
- Subject
- framed masonry; in-plane; numerical simulation; SIM; gap; hysteretic curve; energy dissipation; model calibration; model verification; pushover analysis; seismic response
- Identifier
- http://hdl.handle.net/1959.13/1349863
- Identifier
- uon:30454
- Rights
- Copyright 2017 Zhiyu Wang
- Language
- eng
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | ATTACHMENT01 | Thesis | 9 MB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | ATTACHMENT02 | Abstract | 453 KB | Adobe Acrobat PDF | View Details Download |