Study of tuned mass damper for attenuating skyscraper oscillations through project-based learning

Abstract

The intention of the project was to introduce a complex real-life engineering problem in an easy manner to sophomore students, namely, the topic of a tuned mass damper (TMD). Even though TMD is a multiple-degree-of-freedom vibration problem seen only in advanced university courses, the phenomenon of earthquake effects on buildings is easy to understand. In order to ease the complexity, the multi-degree-of-freedom mathematical problem was converted into a single degree of freedom, such as the behavior of a vertical single-mass cantilever beam. Through a do-it-yourself project to be done in home conditions, students are introduced to the topic of mechanical vibrations via seismic action on tall buildings. Two sections of the "Engineering Mechanics: Dynamics" course, with an overall number of 58 students, participated in the project. The project develops critical thinking and inquiry skills by designing and constructing the physical prototype of a building-like structure and its corresponding tuned mass damper; conducting an experiment under certain restrictions to test the stabilizing effect of the damper after an initial displacement; learning a proper software application to graph and measure underdamped oscillations; calculating corresponding vibration parameters; as well as analyzing and discussing experimental results. Students approach the problem of mass-damper tuning by means of trial and error, an on-purpose strategy to add fun and gambling to the process, to enthusiastically compete for the best performance in terms of efficiency of attenuation. Data were collected from direct observation, surveys, reports and presentations. The results showed that students positively and enthusiastically responded at all project stages and with a better understanding of the phenomenon and engagement in comparison with previous students of the same course without project. The impact of the project on students’ engagement and implications for engineering education are discussed.