Vibration tests on interconnected timber elements using wood-wood connections

Abstract

Vibration tests were performed on 3 large-scale timber slabs using wood-wood connections with a span of 8.1 meters. 10 impulsive vibration tests per specimen were performed to estimate the initial natural frequency. Vibrations were triggered using a hammer and two acceleration transducers (HBM B12/200) were positioned at mid-span with an acquisition speed rate of 200 Hz. The frequency spectrum was computed according to the Fast Fourier Transform (FFT) algorithm where the first peak represents the natural frequency of the structural element. Furthermore, the damping ratio was determined using the logarithmic decrement. This method is precise to obtain damping ratios of under-damped systems in the time domain. In this case, the first and third peaks of each vibration test were used to compute the damping ratio.