Mass of piled lumber estimated through vibration test

Journal of Wood Science

Official Journal of the Japan Wood Research Society

Table 1 Accuracy of VAM (vibration test, where the specimen is suspended by two threads)

Specimen	l (mm)	M₀ (g)	f₁₀ (Hz)	M (g)	f₁ (Hz)	x_CM = 0		x_CM = x_G
Specimen	l (mm)	M₀ (g)	f₁₀ (Hz)	M (g)	f₁ (Hz)	M_VAM (g)	M_VAM/M₀	M_VAM (g)	M_VAM/M₀
No. 1	1500	7228.0	251.5000	106.0051	245.0000	7542.5	1.04	6823.9	0.94
No. 2	1500	6673.0	250.6250	106.0049	243.7500	7068.4	1.06	6392.9	0.96
No. 3	1500	6188.6	229.0625	106.0041	222.5000	6740.0	1.09	6094.4	0.98
No. 4	1599	7305.0	219.0000	106.0036	213.7500	8182.4	1.12	7452.7	1.02
No. 5	1599	7070.0	216.8750	106.0021	211.5625	7993.7	1.13	7280.1	1.03

l: specimen length; M₀: measured specimen mass; f₁₀: resonance frequency of the first mode without the concentrated mass; M: concentrated mass; f₁: resonance frequency with the concentrated mass of the first mode; x_CM: position of the concentrated mass; x_G: center of gravity of the concentrated mass (15 mm from the end); M_VAM: estimated specimen mass by VAM