The Measurement of Fiber Volume Content in FRP by Ultrasonic Wave Method

Abstract

A method was devised to determine the fiber volume content (V_f) in FRP by the ultrasonic wave technique. When the ultrasonic wave length was shorter than the diameter of the fiber, V_f could be easily determined by this method.
However, when the ultrasonic wave length was longer than the diameter of the fiber, V_f could not be determined by the ultrasonic wave method only, but it was necessary to use an approximate solution for the transverse rigidity of FRP under the test.
The fiber volume contents of glass FRP and carbon FRP determined by this non-destructive method were in good agreement with those determined by the commonly-used destructive method.