Measurements of Complex Dynamic Moduli for Laminated Fiber-Reinforced Composites

Measurements of storage and loss moduli are reported for laminated glass fiber reinforced epoxy composite beams at frequencies up to 9400 Hz. The storage moduli were relatively insensitive and the loss moduli sensitive to the frequency at which they are measured. The storage moduli of the laminates can be predicted from a knowledge of constituent layer properties, but only qualitative predictions of the loss moduli can be so obtained. The loss moduli are equal to or larger than those predicted from ply properties.