Rapid indentification of seismic demands in cable-stayed bridges by using acceleration response time histories : a modal decomposition approach | |
| Author | Chit Hsu Han |
| Call Number | AIT Thesis no.ST-24-12 |
| Subject(s) | Structural health monitoring Bridges--Safety measures Vibration |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Structural Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | This study develops the seismic demands evaluation scheme for cable-stayed bridges by utilizing the time history of acceleration responses from the limited installed sensors. The procedure is based on the modal decomposition technique which is derived from the principle of vibrational mode. OFM (Orthogonal Filter Matrix) was used to conduct modal decomposition.The governing modes were selected based on the displacement demands by using RSA analysis. A total number of 140 modes which were excited under earthquake excitation were reduced to 14 modes. The placement of the sensors was optimized based on the selected governing modes. The orthogonal filter matrix was formulated based on the developed sensor system. The acceleration response time histories obtained from the mounted sensors were transmitted through the constructed OFM, to get the modal accelerations. Later, modal coordinates were obtained by double-integrating the modal accelerations.The developed Orthogonal Filter Matrix was verified by conducting the RSA analysis and LRHA analysis by applying the X, Y and Z direction ground motion independently. Subsequently, this matrix was utilized under the three-component ground motion excitation. This approach was additionally verified with high-intensity ground motion as well. The results obtained by this approach were found to be precise when compared to LRHA analysis results. Therefore, this modal decomposition approach using the limited acceleration data could accurately and reliably predict the seismic responses of a complex cable-stayed bridge, as well as identify the structural damage. |
| Year | 2024 |
| Type | Thesis |
| School | School of Engineering and Technology |
| 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) | Anwar, Naveed;Punchet Thammarak |
| Scholarship Donor(s) | Loom Nam Khong Pijai (Greater Mekong Subregion) Scholarships |
| Degree | Thesis (M. Eng.) - Asian Institute of Technology, 2024 |