“ZOOMBDFT”法高精度求系统阻尼比的探讨

Investigation on High Precision Calculation for Damping Ratio Using ZOOMBDFT" Method

提出了用“ＺＯＯＭＢＤＦＴ”（聚焦细化大容量数据谱分析）法高精度求系统阻尼比的途径和计算实例，文内指出了国内外常规１Ｋ字节ＦＦＴ计算系统阻尼比的不合理性，指出了采样时间长度Ｔ是影响频域用半功率带宽法求阻尼比精度的关键因子。

In this paper,a new method of high precision calculation for damping ratio,namedZOOMBDFT' and some examples are introduced.It is poined out that the traditional method of 1K bytes FFT is not appropriate to the calculation of structural damping ratio,and the key tactor affecting the precision in the calculation by using half power bandwidth method lies in the sampling duration T.Two criteria upon which to guarantee the accuracy in the damping calculation are set up.