Application of acoustography for the ultrasonic NDE of aerospace composites

A series of epoxy carbon fibre development panels manufactured as part of a BAE SYSTEMS, Airbus, Composite Wing Development programme were evaluated using Acoustography, a new ultrasonic Non Destructive Evaluation (NDE) method being developed by Santec Systems Inc, as an alternative to the conventional point- by- point ultrasonic C-scan. This study provides details on a novel wide area Acousto-optic (AO) sensor that can be used to nondestructively evaluate materials and components in near real-time. A description of the technology and how it compares to conventional ultrasonic methods is provided. The results of 4 experiments are also provided. The first experiment involves performing ultrasonic and Acoustography tests on thick graphite/epoxy composite panels that have embedded inclusions of known sizes. The objective of this experiment is to determine if the capabilities (i.e. resolution) of Acoustography are comparable to those of conventional ultrasonic techniques. The second experiment involves applying ultrasonics and Acoustography to evaluate a 10mm thick graphite/epoxy composite panel containing defects associated with the manufacturing process. The third and fourth experiments detail the inspection of complex shaped composite parts representative of aerospace applications. Effort has been conducted towards demonstrating the effectiveness of the technology and establishing a baseline for projected inspection times.