Experimental investigations into fluid-structure interactions between a cantilever beam and axially flowing water at different mass flow rates

This thesis presents an experimental investigation into the response of a cantilever beam experiencing axial flow induced vibrations with the free boundary condition at upstream. The acceleration of the beam was captured at two locations using MEMS based accelerometers. The experimental results were compared with known characteristics of each of the three types of responses known to result from flow induced vibrations in axial flow. The observed phenomena can be classified as non-resonant buffeting response driven by the turbulent flow of the fluid.

Experimental investigations into fluid-structure interactions between a cantilever beam and axially flowing water at different mass flow rates

This thesis presents an experimental investigation into the response of a cantilever beam experiencing axial flow induced vibrations with the free boundary condition at upstream. The acceleration of the beam was captured at two locations using MEMS based accelerometers. The experimental results were compared with known characteristics of each of the three types of responses known to result from flow induced vibrations in axial flow. The observed phenomena can be classified as non-resonant buffeting response driven by the turbulent flow of the fluid.

Comfort Evaluation of Double-Sided Catwalk for Suspension Bridge due to Wind-Induced Vibration

Buffeting response of a double-sided catwalk designed for Maputo Bridge was investigated considering wind load nonlinearity, geometric nonlinearity, and self-excited forces. Buffeting analysis was conducted in time domain using an APDL-developed program in ANSYS, and the results were compared with the buffeting response under the traditional linear method. The wind field was simulated using the spectra representation method. Aerostatic coefficients were obtained from section model wind tunnel test. Parameter study has been carried out to investigate the effects of cross bridge interval and the gantry rope diameter on buffeting response. Referring to the ISO 2631-1(1997) standard and the annoyance rate model, the comfort of catwalk due to wind-induced vibration was evaluated. The results indicate that traditional linear calculation methods will underestimate the buffeting response of the catwalk, and enlarging the gantry rope size as well as decreasing the cross bridge interval would increase the comfort level. Moreover, the effect of gantry rope diameter was obvious than that of cross bridge interval. Annoyance rate model can evaluate the comfort level quantitatively compared to the ISO standard.