@inproceedings{oai:kyutech.repo.nii.ac.jp:00006463, author = {Matsuda, Kazutoshi and 松田, 一俊 and Kato, K. and Cao, N. and Shigetomi, K. and Ejiri, K.}, month = {Nov}, note = {In 2009, Ikitsuki Bridge, a truss bridge in Nagasaki Prefecture with a center span length of 400 m, was discovered to have a crack in the diagonal member of the bridge. The side ratio of the section was B/D=1.18. Since motion-induced vortex vibration has not been confirmed on rectangular cross sections with side ratios of B/D<2 according to the past wind tunnel tests, wind tunnel tests were carried out. The tests had an additional purpose of clarifying the effects of the small protruding lips of flanges in steel structures on motion-induced vortex vibration. Spring-supported tests, smoke flow visualizations were performed with or without small protruding lips of flanges changing angle of attack. It was found that motion-induced vortex vibration were confirmed with a rectangular cross section with a side ratio of B/D=1.18 by experimental results of a spring-supported tests, an unsteady aerodynamic lift measurement and a flow visualization test. The effects of the existence of small protruding lips of flanges became large when angle of attack became greater than 3-4 degrees., 12th Pacific Structural Steel Conference (PSSC'19), November 9 – 11, 2019, Tokyo Institute of Technology, Tokyo, Japan}, title = {Motion- Induced Vortex Vibration of a Diagonal Member in a Steel Truss Bridge}, year = {2019}, yomi = {マツダ, カズトシ} }