Broughton, W R; Lodeiro, M J; Sims, G D (2001) Validation of procedures for ultrasonic C-Scan inspection of PMCs: internation round-robin. NPL Report. MATC(A)2

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Abstract

Ultrasonic C-scan is the most widely used inspection technique for quality/process control and in-service monitoring of composite structures. Although considerable capital and operational costs are involved, the reliability and traceability of this method is limited due to the absence of international standards and/or universally accepted procedures.
To meet this need, three procedures were drafted in 1997 as part of a research programme that investigated several fundamental aspects of the technique. The procedures covered operation of C-scan equipment, calibration of ultrasonic transducers and production of reference panels with simulated defects. The programme, “Standardised Procedures for Ultrasonic Inspection of Polymer Matrix Composites", was funded under the CARAD scheme of the DTI.
This report presents the results of the International phase of a round-robin (R-R) validation exercise of the operational procedure undertaken by several users. The report includes recommendations by the international participants for improvements to the standardised procedures. Concurrently, the procedures have been re-formatted by BSI and submitted to technical committee BSI ACE/56 (NDT) for consideration as a new work item for AECMA standardisation.
The main results of the international R-R exercise were: (i) defect size was similar to those participants in the UK R-R exercise that sized the defects using the -6 dB defect method; independent of the size, shape and through-thickness location of the insert; (ii) absolute attenuation measurements (not currently practiced) was also in good agreement with the UK participants; and (iii) the procedures have encouraged operators to adopt a methodical approach to C-scan set-up, inspection and documentation, highlighting all the relevant controlling parameters. These R-R results will be used to support the draft standards and to provide precision statements in the finalised standards. This report also provides brief overviews of the objectives and activities of the prior programme.

Item Type:	Report/Guide (NPL Report)
NPL Report No.:	MATC(A)2
Subjects:	Advanced Materials
Last Modified:	02 Feb 2018 13:17
URI:	http://eprintspublications.npl.co.uk/id/eprint/1931

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