Enhanced Ultrasonic 3D Characterisation Of Composites Using Full Matrix Capture Of Array Data

Lead Research Organisation: University of Bristol
Department Name: Mechanical Engineering

Abstract

Recent years have seen increasing interest in the use of thick-section composites for safety-critical components in, for example, primary aircraft structure and fan blades in aero engines. All such components are required to undergo non-destructive evaluation (NDE) during manufacture; this is time consuming and NDE throughput is stretched to its limit internationally. Current composite Non-destructive Evaluation (NDE) is based on a qualitative empirical approach where a single normal-incidence ultrasonic probe is used to estimate the average ultrasonic attenuation from the amplitude of the back-wall reflection. While adequate for accepting or rejecting thin composite panels, this approach does not provide the level of defect characterisation and localisation necessary for the quantitative NDE of larger components.There is a clear and pressing industrial need for quantitative NDE techniques that can be applied to safety-critical composite components both at manufacture and in-service. An ultrasonic technique is the industrially preferred option for reasons of cost, safety and ease of deployment, but increased scanning speeds are required to speed up throughput. However, the conflicting demands of rapid scanning, high-penetration depth and accurate defect characterisation cannot be achieved with a single normal-incidence probe. Instead the data from multiple inspection directions must be combined. The necessary raw data can be rapidly and efficiently obtained using an ultrasonic array, but at present it cannot be exploited. This is due to the lack of (a) an appropriate forward model of oblique wave propagation and scattering processes, and (b) a suitable inversion scheme to turn the raw data into useful information. This is the motivation for the proposed research programme, the aim of which is to develop ultrasonic array data processing techniques based on physical reasoning for the characterisation of safety-critical aerospace composites. The programme requires advancement of the fundamental science of wave phenomena in composites, the solution of a challenging inverse problem and, crucially, the translation of the scientific findings into practical industrial solutions.

Publications

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Humeida Y (2013) Simulation of ultrasonic array imaging of composite materials with defects in IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control

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Li C (2013) Imaging composite material using ultrasonic arrays in NDT & E International

 
Description The detection of defects in thick-section composite components of the type increasingly used in primary structures (e.g. in the aerospace sector) can be significantly improved through the use of ultrasonic arrays with imaging algorithms tailored to the application. For example, algorithms can be tailored to account for the elastic anisotropy of composite materials, to suppress back-scatter from ply interfaces which can mask signals from defects, and to account for beam steering in curved components where the anisotropy is not translationally invariant.
Exploitation Route Algorithms have been implemented in our ultrasonic array demonstration software BRAIN, and trialled in various companies. In 2017, PDW undertook a week-long trip to the US Air Force Research Lab (AFRL) in Dayton Ohio to assist with the implementation of specialist composite imaging algorithms in their copy of our BRAIN software.
Sectors Aerospace, Defence and Marine,Construction,Energy,Manufacturing, including Industrial Biotechology,Transport

 
Description Basic imaging tools and methodology for NDT of planar composite components implemented into free software, BRAIN, produced by the Ultrasonics and NDT Research Group and trialled by various industrial end-users, including Rolls-Royce, Airbus and Qinetiq. The Air Force Research Lab (AFRL) in Dayton Ohio is also using BRAIN to develop inspections for composite aerospace components. We are currently finalising an agreement with GKN to apply methods to their products.
Sector Aerospace, Defence and Marine
Impact Types Economic

 
Title BRAIN 
Description BRAIN is a flexible ultrasonic array data capture and imaging software suite for NDT applications, based around the concept of Full Matrix Capture (FMC) of array data with imaging performed in post-processing. New imaging tools can be readily added to the core. BRAIN is written in Matlab and can be run either from within Matlab or as a standalone Matlab application. 
Type Of Technology Software 
Year Produced 2010 
Open Source License? Yes  
Impact Numerous collaborating companies are known to use BRAIN for trialling new inspection and imaging algorithms. These include Rolls-Royce, BAE System in the UK, Tenaris in Argentina and potentially many others. New array imaging algorithms developed under various programmes are added to BRAIN as they reach maturity. 
URL https://sourceforge.net/projects/bristol-brain/