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

PDF Url : AD0869025

Report Date : Feb 1970

Pagination or Media Count : 29

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 experimental 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.

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

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE