建築物に加わる風圧変動のスペクトルについて

Abstract

The wind pressure fluctuations on structures are very complicated because wind isdisturbed by structures and wind itself changes its direction and velocity, so it is noteasy to know their nature clearly. In order to get information about the wind load onstructures, wind pressure fluctuations on the walls and roofs of an actual house weremeasured, then the power spectrum of wind pressure fluctuations was computed from thetest data. The measurements were carried out against the seasonal wind at Shionomi-saki Wind Effect Labolatory of Kyoto Univ. on Jan. 23rd and Mar. 17th 1963. TheReference wind velocity was 5 n/sec to 18 n/sec at a point 10 m above ground level.There is an open field on the windward side of the house. The results show that thepower spectra on the windward walls were similar to that of a reference wind having nopeak value at any period of pressure fluctuations. On the other hand it will be notedthat the peak values were observed in the case of pressure fluctuations on roofs or eavesat the period of 0.2 sec to 0.3 sec, which show that on roofs or eaves vortices break outperiodically and that on pressure fluctuations they are affected more by the shape of housethan by the turbulence of a natural wind. The period of 0.2 sec to 0.3 sec at whichthe power spectra take peak values, is expected to be shorter when the reference windspeed becomes faster.