The aim of this work package is to: (i) design and manufacture defect artefacts that will be used for the development of operational procedures for each NDE technique and assessments of defect POD and (ii) define an objective POD benchmarking framework which can be used to compare the merits of each NDE technique for selected defect types and thus contribute to capability statements.
The tasks for this WP:
Task 1.1. To consult with collaborators and stakeholders to determine a collection of defect artefacts that will be sourced, designed, manufactured and inspected that are representative of the defects, materials, processing routes and structural elements that are of concern to a range of renewable energy, oil and gas, and transport applications in which FRPs are used.
Task 1.2. To design and manufacture reference defect artefacts (RDAs) in which the defect sizes and locations are well defined and controlled, so that each NDE technique's robustness for accurately and consistently detecting a range of defects can be assessed.
Task 1.3. To design and manufacture natural defect artefacts (NDAs) with defects produced via controlled processing techniques and/or loading mechanisms (fatigue, low velocity impact).
Task 1.4. To design a POD benchmarking framework that can be used to evaluate the detection capability of each NDE technique by experimental and modelling assessments.
Task 1.5. To design and manufacture RDAs for experimental POD assessments.
Task 1.6. To destructively characterise the defects within the NDAs after all NDE inspection trials have been completed using methods including de-plying, fractography and edge replication.
The aim of this work package is to characterise the elastic, dielectric, thermal and optical properties of the materials of interest in VITCEA and which are of specific importance to the assessment and development of ultrasonic phased array, laser shearography, microwave and active thermography NDE methods. These datasets are required for optimising the practical application of phased array and active thermography techniques, and for the theoretical simulation of NDE techniques. The properties will be determined for the same materials as selected for the RDAs and NDAs manufactured in WP1.
The tasks for this WP are:
Task 2.1. To manufacture reference FRP materials
Task 2.2. To generate elastic property datasets for reference FRP materials
Task 2.3. To generate dielectric property datasets for reference FRP materials
Task 2.4. To generate thermal property datasets for reference FRP materials
Task 2.5. To generate optical property datasets for reference FRP materials
The aim of this work package is to optimise and validate scanning NDE techniques, i.e. phased array and air-coupled ultrasonics and microwave, for quantitative defect detection and characterisation of FRP structures. This will be performed using the RDAs and NDAs from WP1. A key objective is to produce draft operational procedures for complementary scanning inspection techniques. In general, ultrasonic or microwave probes are scanned over the area of material under inspection in a raster pattern. By collating measurements at each position sampled, a 2D or 3D representation of the defects within the material can be produced.
The tasks for this WP are:
Task 3.1. To simulate the ultrasound fields in anisotropic composite materials and determine the ultrasonic probe steering parameters
Task 3.2. To evaluate and develop an ultrasonic phased array inspections and operational procedures using RDAs and NDAs
Task 3.3. To evaluate and develop ultrasonic air-coupled inspections and operational procedures using RDAs and NDAs
Task 3.4. To simulate and validate the interaction between ultrasound and defects
Task 3.5. To experimentally and theoretically assess POD for ultrasonic inspection techniques
Task 3.6. To evaluate and develop microwave inspection techniques and draft an operational procedure
Task 3.7. To simulate the interaction between microwaves and anisotropic composite materials containing defects
Task 3.8. To experimentally and theoretically assess POD for microwave inspection techniques
The aim of this work package is to optimise and validate active thermography and laser-shearography as full-field, fast and non-contact NDE techniques for quantitative testing of FRP structures. The main objective of the application of these methods is the detection and quantitative characterisation of defects based on parameters such as size and depth. Initially, the methods will be evaluated to define the selection of excitation sources, methods of data acquisition and algorithms used for data analysis and visualisation. Subsequently, validation using the RDAs and NDAs from WP1 will be carried out and the possibility of a direct simultaneous application and comparison of active thermography and laser-shearography will be investigated.
The main challenge for WP4 will be the quantitative characterisation of real defects. Real defects are generally not well-defined either in shape, nature or boundaries. In addition, adhesion strength may be highly variable over the delaminated area, thus making quantitative analysis of delamination size difficult. Similarly, fibre misalignment, fibre waviness or deep sub-surface defects may show only weak surface perturbations as the penetration depth of these surface measuring methods is limited, making these types of defect difficult to detect. Another important factor is the detection and quantification of impact damage, where often the larger damage area or splitting appears at the back face of the structure, which is not always accessible. In order to address these challenges, a systematic evaluation of the limits of each NDE method will be required.
In order for the operational procedures developed within VITCEA to be suitable for adoption by NDE and composite users, and to facilitate their future progression into standards, it is essential that their applicability and robustness are demonstrated. The aim of this work package is to provide an assessment of this for the operational procedures developed in WP3 and WP4. Two methods will be used for this; intercomparison exercises and field trials.
The aim of this work package is to create impact for all relevant stakeholders from industry, standardisation committees and the scientific community. The results of the project will be made publicly available, training provided, and exploitation pursued. Input from a Stakeholder Committee will also be used to help direct the work undertaken in VITCEA. Project results and outputs will be disseminated via a number of knowledge transfer mechanisms including the VITCEA web-site, conference presentations, journal papers, good practice guides, articles and publications, representation on standards committees and workshops.