时间 : 2019年04月23日 17时00分
地点 : 建工馆222室（第一报告厅）
主讲人 : Hiromasa Kawai
Professor Kawai is Emeritus Professor of Kyoto University and VisitingFmolessor tl ToKywDenkiUmverily He was bormin 1947 and wasеuсаuеа аlDераrumеnuо АсШсlешасшуоЕпшгш О1KyotoUniversity He was graduated from Kyoto Lniversity in1970.He
from KvotoUniversitw in 1982
Professor Kawai started his acaulernie caurier at Disaster PreventionResearch Institute of Kvoto Universitv in 1972. After 5 years as a researchassociate in DPRI, he became an associate professor at Department ofCivil Engineering of Tokyo Denki University in 1977. He was Professor of the same department from 1991 to 2000 He was a councilor from 1994 to2000 and an associate president in the same university in 1995- -1998. Hebecame Professor or DPRI in 20 Afier a retirement from KyotoUniversity in 2012, he became Professor Emeritus of Kyoto University andregistered as Visiting Professor of Tokyo Denki University from 2012.
Prolessor Kawai was a visiting scientist. at. DAMTP in University of Cambridge from 1974 to 1976 and wasworking with Professor Julian Hunt. He was a visiting researcher of Beijing Jiaotong Universily from 2012.and. a member of Project ll. Since 1970 he has been invlved in Architectural Institute of Japarn and tookaleadership of a wind engineering group to publish ALJ Recommendations for Loads on Building. He made aneffor. to establish Japan Asociation of Wind Engineering and became a member of the Executive Committeefrom 1908. He was president of JAWE from 2010 to 2012. He was a chairman of the Comitte for WindEffets on Steel Suructures in Japanese Society of Sleel Construction in 1999 , 2003.
Professor Kawai's experimental and theoretical research was related to problems in the wind resistant designfor buildings and houses. His studies of wind pressure on buldings and wind induced vibration of buikdinghave. been implemented to a Building Law and Reccommendation for Loads on Buildingx
Experimental results for aero- -elastic vibration tesLs for 3D rectangular prisms with the side ratio 1:2 showthe follwing characteristics for the galoping vibration.
1. Galoping starls around a resonant velocity of Karman vortex shedding.
2. The onset velocity and the amplitude are not afted by a structural damping in the initial stage of thegalloping buL the onset. velo:ity increases with the structural mass.
3. When suructural damping or Scruton nunber is larger than sone criucal value, the amplitude suddedlydecreases like as vortex induced vibration.
4. The amplitude increase linearly to the velocitly from the resonant velocity for Karman vortex shedingAcording to the reladionsipo between the amplitude and the velocity, the St rouhal number is constant. duringthe galoping when the characteristic length is taken by the sum of the width of the model and 2 time of theamplitude, that isB+ 2y. This fact supports that an idea of uriversal Srouhal number is apliable for thegalloping vibration.
The. simnltaneous measurement of velocity in the wake of the prism and the vibration shows that the wavepaltern of the. wake unduladion keeps similar during the galoping to that or the vortex paem sheding fromthe stationary prism with the width of B+2y.
In the lecture, the other interesting findings for 2D rectangular prisms are also shown.