Damping Loss Factor Determination of Glass and Graphite Fiber Composites
Abstract
Material damping of laminated composites is experimentally determined using a cantilever beam test with an impulse excitation. Data acquisition and manipulation is carried out using both an IBM PC-AT and a GenRad 2500 Series FFT Analyzer. Unidirectional continuous fiber 0 and 90 degree laminates were fabricated from glass/epoxy (Hercules S2-Glass/3501-6), graphite/epoxy (Hercules AS4/3501-6) and graphite/polyetheretherketone (ICI AS4/PEEK (APC-2)) to investigate the effect of fiber and matrix properties as a function of frequency, up to 1000 Hz., on the damping of composites. The S2-glass/3501-6 composite had a higher loss factor than the AS4/3501-6 exhibiting a linear increase with increasing frequency and the loss factor for the S2-glass varying nonlinearly with frequency. The 90 degree material exhibited a higher damping loss factor than the 0 degree, varying nonlinearly with increasing frequency. In the 90 degree orientation, the glass fiber composite had loss factors that was approximately a factor of 2 greater than the 0 degree orientation. The 0 degree AS4/PEEK had a loss factor that was approximately equal to that of the 0 degree AS4/3501-6. The 90 degree AS4/PEEK had a loss factor that was approximately 50% less than the AS4/3501-6 and 25% greater than the S2-glass/3501-6. Keywords: Vibration damping; Structural composites; Joints; Shipbuilding.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1989
- Accession Number
- ADA214535
Entities
People
- Jojn W. Gillespie Jr
- Roger M. Crane