高層建筑風(fēng)振分析中的模態(tài)組合問題
發(fā)布時(shí)間：2018-09-08 15:43
【摘要】：大多數(shù)超高層建筑具有兩個(gè)側(cè)移振動(dòng)固有頻率非常接近的特點(diǎn),使得風(fēng)振響應(yīng)分析中不能忽略其模態(tài)相關(guān)性。但目前普遍采用的SRSS(Square Root Squares)與CQC(Complete Quadratic Combination)模態(tài)組合方法存在理論上的不足,在實(shí)際工程應(yīng)用中不能正確把握風(fēng)致結(jié)構(gòu)響應(yīng)特點(diǎn),對(duì)結(jié)構(gòu)的抗風(fēng)優(yōu)化設(shè)計(jì)帶來一定的困惑甚至誤導(dǎo)。理論分析與數(shù)值計(jì)算證實(shí)了這兩種方法的缺陷。SRSS方法完全忽略了模態(tài)相關(guān)性。CQC方法雖然在一定程度上考慮了模態(tài)相關(guān)性,但未能反映模態(tài)相關(guān)性中的相位關(guān)系,導(dǎo)致過于保守的計(jì)算結(jié)果。根據(jù)隨機(jī)振動(dòng)的基本理論,可建立基于風(fēng)荷載互譜密度函數(shù)的模態(tài)組合新方法(稱為"CS模態(tài)組合法")。這一方法能夠完整考慮相鄰模態(tài)之間的幅值相關(guān)性與相位相關(guān)性,原理清晰,計(jì)算簡(jiǎn)單,具有實(shí)際可操作性。與時(shí)域模擬結(jié)果的比較驗(yàn)證了這一新方法的可靠性與精確性。
[Abstract]:Most super-tall buildings have the characteristics that the natural frequencies of two lateral vibration are very close so the modal correlation can not be ignored in the analysis of wind-induced vibration response. However, the modal combination method of SRSS (Square Root Squares) and CQC (Complete Quadratic Combination), which is widely used at present, has some theoretical shortcomings, and it can not correctly grasp the characteristics of wind-induced structure response in practical engineering application, which brings some confusion and even mislead to the optimal design of wind-resistant structure. Theoretical analysis and numerical calculation prove that the defect of the two methods. SRSS completely ignores the modal correlation. CQC method does not reflect the phase relationship of modal correlation, although the modal correlation is considered to some extent. Resulting in overly conservative calculations. According to the basic theory of random vibration, a new method of modal combination based on cross-spectral density function of wind load (called "CS modal combination method") can be established. This method can completely consider the amplitude correlation and phase correlation between adjacent modes. The principle is clear, the calculation is simple, and the method is practical. The reliability and accuracy of the new method are verified by comparison with time domain simulation results.
【作者單位】： 浙江大學(xué)建筑工程學(xué)院;
【基金】：國(guó)家自然科學(xué)基金面上項(xiàng)目(51578505)
【分類號(hào)】：TU973.213
，
本文編號(hào)：2230958
[Abstract]:Most super-tall buildings have the characteristics that the natural frequencies of two lateral vibration are very close so the modal correlation can not be ignored in the analysis of wind-induced vibration response. However, the modal combination method of SRSS (Square Root Squares) and CQC (Complete Quadratic Combination), which is widely used at present, has some theoretical shortcomings, and it can not correctly grasp the characteristics of wind-induced structure response in practical engineering application, which brings some confusion and even mislead to the optimal design of wind-resistant structure. Theoretical analysis and numerical calculation prove that the defect of the two methods. SRSS completely ignores the modal correlation. CQC method does not reflect the phase relationship of modal correlation, although the modal correlation is considered to some extent. Resulting in overly conservative calculations. According to the basic theory of random vibration, a new method of modal combination based on cross-spectral density function of wind load (called "CS modal combination method") can be established. This method can completely consider the amplitude correlation and phase correlation between adjacent modes. The principle is clear, the calculation is simple, and the method is practical. The reliability and accuracy of the new method are verified by comparison with time domain simulation results.
【作者單位】： 浙江大學(xué)建筑工程學(xué)院;
【基金】：國(guó)家自然科學(xué)基金面上項(xiàng)目(51578505)
【分類號(hào)】：TU973.213
，
本文編號(hào)：2230958
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