高层建筑风振分析中的模态组合问题
发布时间：2018-09-08 15:43
【摘要】：大多数超高层建筑具有两个侧移振动固有频率非常接近的特点,使得风振响应分析中不能忽略其模态相关性。但目前普遍采用的SRSS(Square Root Squares)与CQC(Complete Quadratic Combination)模态组合方法存在理论上的不足,在实际工程应用中不能正确把握风致结构响应特点,对结构的抗风优化设计带来一定的困惑甚至误导。理论分析与数值计算证实了这两种方法的缺陷。SRSS方法完全忽略了模态相关性。CQC方法虽然在一定程度上考虑了模态相关性,但未能反映模态相关性中的相位关系,导致过于保守的计算结果。根据随机振动的基本理论,可建立基于风荷载互谱密度函数的模态组合新方法(称为"CS模态组合法")。这一方法能够完整考虑相邻模态之间的幅值相关性与相位相关性,原理清晰,计算简单,具有实际可操作性。与时域模拟结果的比较验证了这一新方法的可靠性与精确性。
[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.
【作者单位】： 浙江大学建筑工程学院;
【基金】：国家自然科学基金面上项目(51578505)
【分类号】：TU973.213
，
本文编号：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.
【作者单位】： 浙江大学建筑工程学院;
【基金】：国家自然科学基金面上项目(51578505)
【分类号】：TU973.213
，
本文编号：2230958
本文链接：https://www.wllwen.com/jianzhugongchenglunwen/2230958.html
