利用SIMULINK仿真工具对水平双向地震输入下偏心结构的楼板谱进行了计算,研究了影响楼板谱变化的几个重要参数,最后对现行抗震设计规范中楼板谱计算的SRSS(Square Root of the Sum of Squares)方法进行了分析,并指出了它的不足。研究结果表明:改变附属结构质量楼板谱峰值区域会有显著的变化,调谐频率处楼板谱变化最明显,地震动卓越频率处楼板谱变化相对较小;改变偏心结构和附属结构阻尼比都会引起楼板谱的变化,但是二者影响的效果不同;附属结构所在楼层和层内位置的改变,使楼板谱发生变化:偏心结构偏心距对楼板谱有较复杂的影响;规范楼板谱在非峰值区域比较精确,在峰值区域存在较大误差,当偏心结构在地震作用下不同方向耦合效应明显时,规范楼板谱在非峰值区域也存在一定的误差。
The floor response spectrum of the eccentric structure subjected to two-dimensional horizontal earthquake input is computed on SIMULINK emulator, and a few influential key parameters are also discussed. In the end the shortcomings of the SRSS (Square Root of the Sum of Squares) method used in the current seismic design code are indicated. The results show that with the subsystem's mass varying the floor response spectrum changes significantly at the tuned frequency, and less significatnly at the earthquake dominant frequency. The floor response spectrum is varied with different damping ratios of the eccentric structure and the subsystem. Furthermore, spatial locations of the subsystem influence the floor response spectrum, so does the eccentric distance of the eccentric structure. The latter is more complicated. The floor response spectrum obtained according to the design specifications is not proper in the peak-value region, and it is proper outside the peak-value region if the multi-directional coupling phenomenon is not significant.