【摘要】：大跨空間結(jié)構(gòu)是風(fēng)敏感結(jié)構(gòu),風(fēng)荷載和風(fēng)致振動(dòng)常常是控制結(jié)構(gòu)安全的主要因素。隨著我國經(jīng)濟(jì)的發(fā)展和技術(shù)水平的提高,大跨空間結(jié)構(gòu)被越來越多地應(yīng)用到現(xiàn)代工程中。然而近年來也有一些大跨空間結(jié)構(gòu)在風(fēng)荷載作用下發(fā)生破壞�；诖�,大跨空間結(jié)構(gòu)抗風(fēng)設(shè)計(jì)越來越受到工程人員的重視。本文數(shù)據(jù)來源于開敞式葉片形空間網(wǎng)格結(jié)構(gòu)屋蓋實(shí)測(cè)風(fēng)荷載及風(fēng)振響應(yīng)。通過在上下屋蓋對(duì)應(yīng)布置12對(duì)風(fēng)壓傳感器,實(shí)時(shí)測(cè)量屋蓋表面的風(fēng)荷載信息,通過現(xiàn)場(chǎng)風(fēng)速儀記錄對(duì)應(yīng)時(shí)刻的來流信息,通過在屋蓋布置速度傳感器測(cè)量結(jié)構(gòu)風(fēng)致速度響應(yīng)�；趯�(shí)測(cè)風(fēng)速,分析來流的風(fēng)速譜與湍流強(qiáng)度,研究發(fā)現(xiàn)不同時(shí)段的風(fēng)速譜縱坐標(biāo)略有不同,但是曲線整體變化規(guī)律一致。與經(jīng)典的Davenport譜、Von Karman譜和Kaimal譜比較,在中低頻段,實(shí)測(cè)風(fēng)速譜曲線與經(jīng)典譜曲線基本一致；在高頻段,兩者則有較大差異。由于后期新增建筑對(duì)場(chǎng)地的影響,場(chǎng)地粗糙度(結(jié)構(gòu)設(shè)計(jì)取為B類地貌)發(fā)生變化,實(shí)測(cè)湍流強(qiáng)度位于C類與D類之間,與日本規(guī)范Ⅳ地貌湍流強(qiáng)度相當(dāng),說明建筑設(shè)計(jì)要考慮后期規(guī)劃建筑對(duì)場(chǎng)地粗糙度的影響,否則建筑可能偏于不安全。分析了實(shí)測(cè)風(fēng)壓頻譜特性,考察了測(cè)點(diǎn)之間的相關(guān)系數(shù),測(cè)點(diǎn)之間的相關(guān)系數(shù)絕對(duì)值均少于0.2,屬于弱相關(guān)。其原因一方面是各測(cè)點(diǎn)之間的距離較大,且上下屋面不透風(fēng),空氣對(duì)流較少；另一方面是風(fēng)壓測(cè)點(diǎn)集中布置在屋蓋中間區(qū)域,距離風(fēng)壓復(fù)雜的屋檐、拐角區(qū)域較遠(yuǎn)。分別利用峰值因子法、Hermite級(jí)數(shù)法和sadek-simiu法三種方法計(jì)算得到了實(shí)測(cè)風(fēng)壓的峰值因子,比較了三種計(jì)算結(jié)果的差別及峰值因子的變化范圍,給出了該類開敞式空間網(wǎng)格結(jié)構(gòu)的峰值因子建議取值。與標(biāo)準(zhǔn)高斯分布概率密度曲線相比,實(shí)測(cè)風(fēng)壓概率密度曲線對(duì)稱性較好,在曲線尾部較標(biāo)準(zhǔn)高斯曲線略高。實(shí)測(cè)風(fēng)壓偏度和峰態(tài)較一般風(fēng)洞試驗(yàn)結(jié)果小,實(shí)測(cè)風(fēng)壓非高斯特性并不明顯。根據(jù)偏度和峰態(tài)的曲線關(guān)系及其累計(jì)分布函數(shù),提出了風(fēng)壓非高斯區(qū)域劃分依據(jù)�；趯�(shí)測(cè)風(fēng)壓功率譜及概率統(tǒng)計(jì)參數(shù),分別采用Yamazaki-Shinozuka方法和Forrst-Gurley方法模擬了風(fēng)壓時(shí)程,兩者功率譜吻合較好,同時(shí)表征非高斯特性的偏度、峰態(tài)參數(shù)也在合理誤差范圍內(nèi)�；诮Y(jié)構(gòu)實(shí)測(cè)振動(dòng)速度響應(yīng),分別利用隨機(jī)減量法、峰值拾取法和頻域分解法得到了結(jié)構(gòu)實(shí)測(cè)自振頻率和豎向振動(dòng)模態(tài),對(duì)比有限元模型頻率及模態(tài)結(jié)果,兩者自振頻率誤差在10%以內(nèi),且結(jié)構(gòu)豎向模態(tài)吻合較好。采用多項(xiàng)式擬合數(shù)據(jù)去除趨勢(shì)項(xiàng)方法得到了積分位移信號(hào),分析位移信號(hào),結(jié)構(gòu)振動(dòng)較小,且呈現(xiàn)周期性。本文應(yīng)用現(xiàn)場(chǎng)實(shí)測(cè)方法,綜合研究了大跨結(jié)構(gòu)的風(fēng)致響應(yīng)與風(fēng)荷載特性。研究成果可豐富大跨結(jié)構(gòu)風(fēng)效應(yīng)的知識(shí)和抗風(fēng)設(shè)計(jì)方法,同時(shí)可為大跨建筑的設(shè)計(jì)與建造提供有科學(xué)意義的參考。
[Abstract]:Long span space structure is a wind sensitive structure. Wind load and wind induced vibration are often the main factors to control the safety of the structure. With the development of economy and the improvement of technology, large span space structure is applied to modern engineering more and more. However, in recent years, some large span space structures have been damaged under wind load. Based on this, the wind-resistant design of long-span space structure is paid more and more attention by engineers. The data in this paper are derived from the measured wind loads and wind-induced vibration responses of open vane space grid structures. By arranging 12 pairs of wind pressure sensors corresponding to the upper and lower roof, the wind load information on the roof surface is measured in real time, the flow information at the corresponding time is recorded by the field anemometer, and the wind induced velocity response of the structure is measured by placing the velocity sensor in the roof. Based on the measured wind speed, the wind velocity spectrum and turbulence intensity are analyzed. It is found that the longitudinal coordinates of wind speed spectrum are slightly different in different periods, but the overall variation of the curve is consistent. Compared with the classical Davenport spectrum Von Karman spectrum and Kaimal spectrum, the measured wind velocity spectral line is basically the same as the classical spectral curve in the middle and low frequency range, but there is a great difference between them in the high frequency range. Due to the influence of the new buildings on the site, the roughness of the site (structural design is taken as B geomorphology) is changed. The measured turbulence intensity lies between class C and D, which is equivalent to the turbulence intensity of the Japanese code 鈪，

本文編號(hào)：2119223