Modal properties of structures (namely natural frequency and damping ratio) play critical roles in design and analysis of new and existing structures and are found to be closely related with the vibrational amplitude. This amplitude-dependent effect is not well characterized due to the relative lack of adequate data on the real behavior of full-scale structures. The paper focuses on the investigation into the amplitude- dependent modal properties of the Nelson St off-ramp bridge (part of the motorway network in Auckland’s CBD, New Zealand) by large shaker forced vibration testing. Different levels of steady-state sin-swept excitations were generated in the vicinity of the natural frequencies of the bridge. A series of normalized frequency response function curves under the condition of different loading scenarios were constructed, from which natural frequencies and damping ratios were identified. The obtained quantitative relationship between natural frequencies/damping and response amplitude was used to describe the amplitude-dependent dynamic behavior.
|Title of host publication||Life-Cycle of Structural Systems: Design, Assessment, Maintenance and Management|
|Subtitle of host publication||Proceedings of the 4th International Symposium on Life-Cycle Civil Engineering, IALCCE2014|
|Editors||Hitoshi Furuta, Dan M. Frangopol, Mitsuyoshi Akiyama|
|Number of pages||7|
|Publication status||Published - 21 Oct 2014|
|Name||Life-Cycle of Civil Engineering Systems|