3D characterisation of composite laminates using ultrasonic analytic signals
Abstract
The aerospace and automotive industries are designing lighter structures with composites, driven by environmental targets on CO2 emissions, and are requiring higher-fidelity non-destructive information about the internal structure of manufactured composite components. This is to better inform the design and test process as well as, at the production stage, to confirm conformance to design and underpin decisions about concession of defects. Consistent research progress over the last decade has gradually revealed a wealth of detailed information within the ultrasonic pulse-echo response from composite laminates. Unlocking that information requires careful treatment of various unwanted effects such as phononic band gaps and phase singularities in the data, followed by inversion methods to convert the ultrasonic data into three-dimensional maps of actual material properties. As a result, any tape gaps and overlaps can be tracked and deviations from the design such as wrinkles can be quantified using the metrics that have been shown to be the most influential on the compression strength. This presentation will present each stage in the state-of-the-art processes developed by the authors and apply them to real composite specimens including comparison with X-ray CT and micro-section information.
