A STUDY OF THE ELASTIC PROPERTIES OF ORIENTED FIBERGLASS BY THE IMPULSE ACOUSTICAL METHOD
Abstract:
The impulse acoustical method was used to determine the elastic properties of SVAM oriented glass reinforced plastics. Formulas were given for Youngs modulus, shear modulus, and Poissons ratio. These constants were related to the density of the material and the speed of elastic wave propagation in the material. An equation was given for the speed of elastic wave propagation in any direction as a function of the angle and speed of propagation relative to the fiber direction. Experimental values of the elastic constants were obtained in three SVAM materials having an epoxy phenol resin binder, densities ranging from 2.01 to 2.08 gcm superscript 3, glass fiber contents ranging from 72 to 78 wt percent, and ratios of longitudinal to transverse fibers of 1 to 1 ratio and 1 to 5 ratio. A schematic diagram showed the experimental arrangement of ultrasonic generator, receiver, and sample. The speed of elastic wave propagation was measured in samples at angles of 0, 15, 30, 45, 60, 75, and 90 degrees tto the fiber direction. Mechanical testing was done to determine values of the elastic constants for comparison with the impulse acoustical method. Experimental results were given for the modulus of elasticity as determined by static and dynamic method.