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Rayleigh阻尼是一种广泛采用的正交阻尼模型。针对一个直径90m,高15m的穹顶结构,分析比较了四种方法(传统方法、最小二乘法、基于多参考振型的加权最小二乘法和基于结构位移峰值误差优化法)所得Rayleigh阻尼系数对结构地震反应计算精度的影响。四条地震波的分析结果表明:基于结构位移峰值误差的优化方法对于结构位移等以低阶模态控制的动力反应量计算精度最高;传统方法存在选择合适第二阶参考频率的难题;而最小二乘法不是计算Rayleigh阻尼系数的合理方法。当结构的显著贡献模态多且不同动力反应相关显著贡献模态的频率有巨大差异时,Rayleigh阻尼模型将无法构造兼顾低阶模态和高阶模态计算精度的阻尼矩阵,此时需要采用更多阶模态的阻尼比等于精确值的阻尼矩阵构造方法。
Rayleigh damping is a widely used orthogonal damping model. For a dome with a diameter of 90m and a height of 15m, the Rayleigh damping coefficients obtained from the four methods (traditional method, least squares, weighted least squares based on multi-reference modes and optimization based on displacement of structural displacement) Influence of Earthquake Response Calculation Precision. The analysis results of four seismic waves show that the optimization method based on structural peak displacement error has the highest computational accuracy for the dynamic response of structural displacement and other modes controlled by low order modes. The traditional method has the problem of choosing the appropriate second-order reference frequency. The least square method It is not a reasonable way to calculate the Rayleigh damping coefficient. The Rayleigh damping model will not be able to construct a damping matrix that takes into account both the low-order modal and the high-order modal computational accuracy as the structures have significant contribution modalities and there are vast differences in the frequencies of significant contribution modalities associated with dynamic responses. The Damping Ratio of Modes is Equal to the Damping Matrix Constructio.