Analysis of aerodynamic stability of long-span suspended bridges

Carepa Cordeiro, Carlos

4. term

Structural and Civil Engineering, Master

2018

2018-06-07

76 pages

On 26th July 1820, the one which is considered as the first suspended bridge was opened ([11]). Union Chain Bridge, spans only 137m connecting England to Scotland. Almost 100 years later, on 25th October 1931, George Washington Bridge, in New York, surpass the milestone of 1000m suspended span ([4]). From that time ahead, the challenges are increasing exponentially, and the goal of reaching suspended spans of two or three thousand meters is now a reality. At the same time, designers are asked to keep the structures lightweight, slender and flexible but, at the same time, large enough to carry the future traffic demands. The combination of all these factors made the engineering science to look into details such as aerodynamics. The effect of wind on suspended bridges, and in any structure in general, can result in catastrophic events as happened on 7th November 1940 with Tacoma Narrow Bridge ([10]). The passion about bridges, and in particular, the challenges presented by the aerodynamic analysis, were the motivational core of the author. The reader will be presented with an aerodynamic analysis of three systems based on up-scaled models of a referential bridge (Great Belt Bridge, Denmark). The aim of the present thesis is to describe and evaluate the procedure for investigate the onset of flutter for long-span systems, through a new theory which differs from Scanlan [9]. The entire procedure is developed since the definition of the cable geometry and its stiffness onto the evaluation of aerodynamic parameters. Due to the complexity of the topic, the author assumes that the reader possesses significant knowledge regarding structural dynamics and aeroelasticity.

aeroelasticity ; aerodynamics ; flutter ; suspended bridges ; long-span

Download
View record in AAU Student Projects