Suppression of multi-mode vibrations of a composite floor by multiple tuned mass dampers | |
| Author | Neupane, Prakash |
| Call Number | AIT Thesis no.ST-00-31 |
| Subject(s) | Composite construction Damping (Mechanics) |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | Application of multiple tuned mass dampers (MTMD) in suppressing multi mode vibrations of a large composite floor having closely spaced natural frequencies were investigated. Unlike structures with widely spaced natural frequencies, a composite floor having closely spaced natural frequencies can not be modelled as a single-degree-of-freedom (SDOF) system due to a large number of vibration modes participating in the response. Therefore, the floor was modelled as a continuous system with distributed properties. On this basis, governing equations of motions of the floor with M modes of vibrations and N MTMD attached were derived from Lagrange's Eauations. Floor responses under a harmonic excitation were computed by frequency domain approach with the help of computer program written in MATLAB. Later, a parametric study was performed to identify optimal design configuration of MTMD and also to evaluate effectiveness of MTMD in suppressing floor response. A set of TMD parameters that minimize floor response was identified by trial and e1rnr approach. Maximum reduction in floor responses in all modes was achieved from 60 TMDs with mass ratio of 2.14% and darning ratio of 5%. It was observed that optimal allocation of TMD is the most important factor in reducing floor response than other TMD parameters. The obtained value of mass ratio was found to be more than double the value of mass ratio commonly used in controlling single mode of vibration. On the other hand, a lower value of damping ratio was obtained compared to the optimum value of damping ratio for a single TMD of the same mass ratio. |
| Year | 2000 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Structural Engineering (STE) /Former Name = Structural Engineering and Construction (ST) |
| Chairperson(s) | Pennung Warnitchai; |
| Examination Committee(s) | Worsak Kanok-Nukulchai ;Barry, William J.; |
| Scholarship Donor(s) | Asian Institute of Technology (Partial Scholarship) |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 2000 |