Accession Number : AD0869025

Title :   Measurement of Damping Coefficients and Dynamic Modulus of Fiber Composites.

Descriptive Note : Technical note,

Corporate Author : ARMY AVIATION MATERIEL LABS FORT EUSTIS VA

Personal Author(s) : Mazza, L. T. ; Paxson, E. B. ; Rodgers, R. L.

Report Date : FEB 1970

Pagination or Media Count : 28

Abstract : The experimental techniques developed to measure the material damping of FRP were exponential decay of a vibrating beam (free- ree mode) and forced vibration of double cantilever beam. By using Zener's anelastic damping values were calculated and compared with experimental damping values. Good agreement was achieved. The expreimental techniques were then applied to FRP and boron-reinforced composites. It was found that damping values for the unidirectional fiberglass and boron composite specimens had approximately the same magnitude as those for the aluminum specimens. However, variations in fiber orientation produced a significant increase in damping coefficients. Also, the introduction of air damping produced an increase in the observed value of material damping. The parameters of stree level and frequency were controlled, and the effect of these parameters ont he values of material damping and dynamic modulus was observed and recorded. (Author, modified-PL)

Descriptors :   (*REINFORCED PLASTICS, DAMPING), (*COMPOSITE MATERIALS, DAMPING), CANTILEVER BEAMS, MODULUS OF ELASTICITY, FIBERS, VIBRATION, BORON ALLOYS, GLASS TEXTILES, SHEAR STRESSES, ALUMINUM ALLOYS.

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE