STP696

    Effects of Material Inhomogeneities on Ultrasonic Measurements: The Problem and a Solution

    Published: Dec 1979


      Format Pages Price  
    PDF Version (352K) 12 $25   ADD TO CART
    Complete Source PDF (9.0M) 12 $55   ADD TO CART


    Abstract

    Most ultrasonic measurements of materials involve the generation of an acoustic wave and the propagation of that wave from a transducer through a coupling medium to a specimen under test. After interacting with the specimen, the wave propagates through the coupling medium to a receiving transducer and is converted to an electrical signal. The information presented to the observer by the electrical signal depends on each element of the system.

    In this paper, we examine the role that the receiving transducer plays in ultrasonic measurements. The phase-sensitive nature of conventional receiving transducers has, for the most part, been neglected in nondestructive evaluations. This is shown to lead to significant data misinterpretation.

    A new acoustoelectric transducer (AET) has been developed which is phase insensitive. Comparative data obtained with both conventional and AET transducers are presented and discussed. The AET is shown to produce more accurate measurements for the cases investigated.

    Keywords:

    ultrasonic measurements, phase-insensitive transducer, acoustoelectric transducer, composite materials, material inhomogeneities, flaws, abolute velocity, attenuation, nondestructive tests


    Author Information:

    Heyman, JS
    Research physicists, NASA Langley Research Center, Hampton, Va

    Cantrell, JH
    Research physicists, NASA Langley Research Center, Hampton, Va


    Paper ID: STP36023S

    Committee/Subcommittee: D30.04

    DOI: 10.1520/STP36023S


    CrossRef ASTM International is a member of CrossRef.