Ambient Vibration Testing for Story Stiffness Estimation of a Heritage Timber Building

Table 1

Identified natural frequencies and damping ratios.

Modes	Descriptions	𝜔FDD (Hz)	𝜔SSI (Hz)	𝜍FDD (%)	𝜍SSI (%)
1	Transversal; (1st lateral mode)	1.13	1.11	2.35	3.07
2	Torsional	1.34	1.35	2.04	3.50
3	Transversal; (1st longitudinal mode)	1.51	1.51	1.38	2.00
4	Transversal; (2nd lateral mode)	4.23	4.20	1.56	2.32

Note: The desciptions of each mode are illustrated in Figure 6.