Stress Wave Attenuation in Thin Structures by Ultrasonic Through-Transmission.
MASSACHUSETTS INST OF TECH CAMBRIDGE
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The steady-state amplitude of the output of an ultrasonic through-trans mission measurement is analyzed and the result is given in closed form. Provided that the product of the input and output transduction ratios the specimen-transducer reflection coefficient the specimen-transducer phase shift parameter and the material phase velocity are known, this analysis gives a means for determining the through-thickness attenuation of an individual thin sample. Multiple stress wave reflections are taken into account and so signal echoes do not represent a difficulty. An example is presented for a graphite fiber epoxy composite Hercules As3501-6. Thus, the technique provides a direct method for continuous or intermittent monitoring of through-thickness attenuation of plate structures which may be subject to service structural degradation. MM
- Laminates and Composite Materials