Evaluation of Vibration Damping of Glass-Reinforced-Polymer-Reinforced Glulam Composite Beams

Abstract

A systematic experimental investigation was conducted to evaluate the damping ratios of unreinforced glulam beams, and glulam beams reinforced with E-glass reinforced epoxy polymer (GRP) plates. The methods considered were the logarithmic decrement, the Hilbert transform, the moving block, and the half band power (HBP) methods. A modification to the HPB method is proposed to improve the method’s accuracy when considering materials with relatively high damping ratios. The influence of the lay up sequence, thickness, and through-the-depth location of the GRP plate on damping of the composite beams is also investigated. The results obtained from our experimental and numerical investigations show that the proposed modification to the HPB method could effectively improve the accuracy of the method when considering the vibration damping of composite materials possessing relatively high level of damping.