Statistical methods applied to acousto-ultrasonic technique

The growth in the extent of applications of composite materials, particularly in commercial products, has been dramatic and carries an implied mandate for effective methods for material quality evaluation. The cost of composite materials dictates that non-destructive test methods be used. At the same time, the nature of composites limits the use of conventional techniques such as radiography , eddy-current or ultrasonics. Recently, a new technique known as the Acousto-Ultrasonic (AU) technique, has been developed and appears to hold promise as a method for the evaluation of composite material quality.

Implementation of the AU method is examined using the zeroth moment method developed by Henneke et.al. A new parameter termed as Acousto Ultrasonic Factor (AUF) has been defined for this purpose. The behavior of the AUF response to specimens of known quality is investigated statistically. It is found that the transformed/actual readings follow a Beta distribution and that specimens of different quality are readily distinguishable using the statistical analysis of the AUF response. Reasonable future steps for translating these findings into efficient quality evaluation methods have been suggested.</p