两空间结构风致内压的复特征值分析

COMPLEX EIGENVALUE ANALYSIS OF WIND-INDUCED INTERNAL PRESSURES FOR A TWO-COMPARTMENT BUILDING

对Sharma提出的两空间结构风致内压线性控制方程组进行复特征值分析,获得了"结构-内压"系统自振频率与阻尼比的表达式。通过典型数值算例,计算分析了系统的自振频率、阻尼比随迎风墙和隔墙开洞面积的变化规律。结果表明,在不同的迎风墙与隔墙开洞面积下,"结构-内压"系统的自身阻尼较小。随着迎风墙面开洞面积的减小,第一阶振型阻尼比急剧增大,但第二阶振型阻尼比基本保持不变;随着隔墙开洞面积的增大,前两阶阻尼比均呈递减趋势。

The effects of wind-induced internal pressure on a two-compartment building with opening cannot be neglected. In this paper, the complex eigenvalue analysis of the non-linear equations proposed by Sharma was conducted. Then, the expressions of natural frequency and damping ratio for the internal pressure-building system were obtained. Finally, the changing tendency of natural frequency and damp- ing ratio with the opening areas of wind-ward and partition walls were studied by using a typical numeri- cal example. The results show that the damp of the system is rather small in case of different opening ar- eas of wind-ward and partition walls. With the decrease of the opening area of wind-ward wall, the first- order damping ratio rapidly increases, but the second-order damping ratio keeps unchanged. Additionally, the two orders damping ratios present a decreasing tendency with the increase of the opening area of partition wall.