Application of Experimental Modal Analysis to Determine Damping Properties for Stacked Corrugated Boxes

Table 3

Damping ratio calculated with the curve-fit method.

Damping ratio calculated with the exponential decay function 𝑋𝑒^−𝜁𝜔𝑛𝑡
𝑋 = 9.7534𝑒^−37.47𝑡 for acceleration	𝜔𝑛 = 38 Hz (𝑐3 and 𝑘3)	𝜁 = 0.157
𝑋 = 9.7534𝑒^−37.47𝑡 for acceleration	𝜔𝑛 = 16 Hz (𝑐2 and 𝑘2)	𝜁 = 0.373
𝑋 = 9.7534𝑒^−37.47𝑡 for acceleration	𝜔𝑛 = 10 Hz (𝑐1 and 𝑘1)	𝜁 = 0.597

Comparing the method of logarithmic decrement with the curve-fit method, the logarithmic-decrement-derived damping ratio (𝜁 = 0.1257) is close to the damping ratio (𝜁 = 0.157) of the 𝑐₃-𝑘₃ structure.