本文在風洞實驗下，將高層建築簡化為二維矩形斷面，同時考慮橫向與扭轉向振動耦合之氣彈模型，在平滑流場中，變化矩柱體之深寬比，扭轉與橫風向振動頻率比及順風項的偏心量，來觀察矩柱體在橫風向及扭轉向產生之氣彈反應及結構體昇力變化及其尾跡現象。結果顯示當勁度中心朝上游偏心時，不同頻率比之擾動昇力及橫風向擾動位移，皆會因偏心量的增加而造成臨界風速時之反應被抑制，反之，當勁度中心朝下游偏心，反應皆提昇。扭轉向的擾動位移，則不論向上或向下偏心，怕隨偏心量的增加而增加。B/D=0.6及頻率比為1.1之變化最顯著，尾跡渦散頻譜峰值之變化與橫風向擾動位移及擾動昇力現象一致，且能相互印證。 In this study, aeroelastic 2-D rectangular prisms were studied in aseries of wind tunnel experiments, simultaneously considering thelateral and torsional vibrations. By controlling the depth-to-width( B/D) ratio of the prisms, torsional/lateral frequency ratio, andeccentricity in the alongwind direction, the aeroelastic displacementof the prisms, fluctuating lift coefficient, and wake behavior weremeasured. Results showed that as the stiffness center was movedupstream, in all B/D and torsional/lateral frequency ratios, thefluctuating lift coefficient and acrosswind fluctuating displacementwere suppressed. As the stiffness center was shifted downstream on theprisms, the fluctuating lift and acrosswind vibration increased. Inboth cases, the torsional movement increased. The changes were mostobvious when B/D=0.6 and the torsional/lateral frequency ratio was1.1. The variations of the peak of the wake spectra, which indicatethe vorticity strength of the vortex shedding, showed the same trendas the acrosswind fluctuating displacement and fluctuating liftcoefficient, thus being able to confirm one another.
Relation:
八十九年度中華民國力學學會年會暨第二十四屆全國力學會議論文集=24th National Conference on Applied and Theoretical Mechanics，頁N.A.(CD)
