A Framework for the Prediction and Mitigation of Flutter in Suspension Footbridges: A Human-Centered Approach
Suspension footbridges provide access to education, healthcare, and economic opportunity to isolated communities all over the world. Despite the construction of hundreds of these footbridges over the past sixty years, their dynamic behavior and vulnerability to wind effects remains largely unknown.
Progress in predicting the overall aeroelastic behavior of bridges to date has been effective in reducing the flutter vulnerability of major infrastructure projects with multi-million dollar budgets and teams of highly specialized bridge aeroelasticity researchers. However, basic flutter analysis remains out of reach for organizations like Bridges to Prosperity, who are building dozens of footbridges a year and lack the expertise and resources to conduct a specialized aeroelastic evaluation of each individual bridge they build. They are further constrained by a lack of knowledge of probabilistic design practices, the unknown dynamic properties of their standardized suspension bridge design, and design engineers without specialized knowledge of
dynamics, much less flutter. In addition, the nature of the communities where Bridges to Prosperity footbridges are built differs considerably from sites where traditional vehicular suspension bridges are built, which introduces additional constraints related to material availability, construction practices, and cultural considerations which impact flutter mitigation options. This combination of constraints renders even the simplest flutter formulations and mitigation strategies inaccessible to designers and builders of rural footbridges.
This study addresses these challenges with a Footbridge Flutter Mitigation Framework which addresses the above constraints by adopting a human-centered approach. The framework offers a comprehensive approach for the prediction and mitigation of flutter in standardized footbridge designs. In contrast to current flutter prediction and mitigation efforts, the framework leverages data from multiple standard footbridges to eliminate the burden of detailed bridge by bridge analysis. A novel set of Design Thinking First Tools is proposed which is tailored to civil engineering applications to infuse the needs and aspirations of community members into the research and design process. The framework includes several components to enable the ongoing collection and analysis of vibrational data from constructed footbridges to inform the dynamic inputs of the flutter analysis platform. The framework includes a probabilistic approach to translate predicted critical flutter velocities into actionable span guideline charts and flutter check tools designed specifically to comply with existing standard design procedures.
History
Date Created
2017-11-27Date Modified
2018-10-04Defense Date
2017-06-30Research Director(s)
Ahsan KareemDegree
- Doctor of Philosophy
Degree Level
- Doctoral Dissertation
Program Name
- Civil and Environmental Engineering and Earth Sciences