The Office of Graduate Administration is pleased to announce that Chenyue Guo will be defending their thesis as a candidate for the degree Master of Applied Science in Engineering.

You are encouraged to attend the defence. The details of the defence and how to attend are included below:

DATE: November 28^th, 2023

TIME: 9:00 AM (PT)

DEFENCE MODE:HYBRID - In-person and Remotely via Zoom

In-Person Attendance: Senate Chambers, UNBC Campus

 Please contact the Office of Graduate Administration for information regarding remote/online attendance. 

To ensure the defence proceeds with no interruptions, please mute your audio and video on entry and do not inadvertently share your screen. The meeting will be locked to entry 5 minutes after it begins: ensure you are on time.

THESIS ENTITLED: VIBRATION SERVICEABILITY PERFORMANCE OF MASS TIMBER FLOORS WITH BEAM SUPPORTS AND CONCRETE TOPPING

ABSTRACT: Mass timber panels are frequently utilized as load-bearing components in the construction of floors, walls, and roofs within mid-rise or high-rise wooden buildings. In comparison to alternative materials like concrete and steel, floors constructed using mass timber panels have relatively lighter weight and lower bending stiffness, which makes them more susceptible to vibrations resulting from human activity. The floor vibration can significantly affect the comfort of its occupants, and the vibration serviceability limit design often governs the maximum allowable span of mass timber floors. The limited quantity and complexity of research on the vibration performance of mass timber floors underscore the urgent need for further investigation.

This research focused on assessing the vibration performance of mass timber slab floors with beam supports and concrete toppings. Each investigation included experimental tests to determine the dynamic properties of these floors and gathered subjective ratings from occupants to evaluate the floor's vibration performance. Additionally, numerical modeling approaches were suggested in each study and verified using test results. The applicability of three contemporary timber floor vibration design methods was assessed by comparing the experimental results with the predictions generated by each method.

The results of this research have highlighted the significant influence of support stiffness on the vibration performance and dynamic properties of mass timber slab floors. Transitioning from rigid wall supports to realistic beam supports can cause a notable shift in the floor's vibration performance, potentially moving it from acceptable to unacceptable. In such cases, the fundamental natural frequency can decrease by more than 40%. The method proposed by Kollar demonstrated a remarkable level of accuracy in predicting the fundamental natural frequency of beam-supported floors. The impact of adding a floating concrete topping to the floor's dynamic properties depends on specific construction details. Within this research, introducing a floating concrete topping to mass timber floors significantly improved their vibration performance. This improvement had the potential to change the initial subjective rating of the floor from unacceptable to acceptable. Various degrees of partial composite action were observed between the concrete and timber layers, even in the absence of mechanical connectors. The commonly used floor vibration design methods exhibited limitations when employed in the design of mass timber floors with varying construction details. To achieve more accurate predictions of their vibration performance, it is strongly recommended that future research efforts focus on making significant improvements.

COMMITTEE MEMBERSHIP:

Chair: Dr. Matt Reid, 

Faculty of Science and Engineering, University of Northern British Columbia

Examining Committee Members:

Supervisor: Dr. Jianhui Zhou,

Faculty of Science and Engineering, University of Northern British Columbia

Committee Member: Dr. Maik Gehloff,

Faculty of Science and Engineering, University of Northern British Columbia

Committee Member: Dr. Sigong Zhang,

School of Engineering, Newcastle University

External Examiner: Dr. Ying Hei Chui,

Department of Civil and Environmental Engineering, University of Alberta