Non-destructive examination (NDE) of composite to steel joints for in-build and through life condition monitoring in the marine environment.

Lead Research Organisation: University of Southampton
Department Name: Faculty of Engineering & the Environment

Abstract

A number of composite to steel joint geometries have been developed for use in ship structures to enable, for example, incorporation of large composite superstructures onto steel hulls. In practice, these joints could be up to 100m or more in length. The ability to ascertain the condition of such joints both at build and through the vessel life is critical to the adoption of composite structures in such hybrid arrangements.
Some joint geometries are amenable to inspection by existing techniques such as thermography or ultrasonic inspection. These typically consist of composite material overlaying a steel substrate. Higher joint strengths have been achieved using geometries where the composite part is bonded into a steel channel and externally over-laminated. These geometries have proved to be incompatible with established non-destructive examination techniques.
The project seeks to identify and develop a method of validating the integrity of a composite to steel joint both at build and through life where the joint includes bond surfaces masked from conventional non-destructive examination (NDE) methods by a steel component. The method developed will be practical for use in an industrial environment including on external ship surfaces.
The project offers an opportunity to develop current state of the art non-destructive evaluation technologies to reveal hitherto hidden defects. The project will address the feasibility of applying novel infra-red/UT approaches to such geometries and establish their usefulness particularly in the construction stage. To reveal the hidden defects a novel sensor system must be developed. A system based on embedded sensors/actuators will be explored to probe deep into the structure and assess any degradation of the joint. It is essential that such a system has minimum impact on the joint integrity and a key part of the project will be to establish the failure envelop of joints with and without the integrated system.
The successful candidate for the PhD will ideally have a strong background in mechanics of composite material and be aware of techniques that are currently in used for condition monitoring and NDE on in service structures such as ships, aircraft, bridges and off-shore structure.

Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/N509358/1 01/10/2015 30/09/2020
1786410 Studentship EP/N509358/1 26/09/2016 30/09/2020 Geir Olafsson
 
Description Defect can occur in any material, but one type of material that is particularly effect and susceptible to defects is composite materials such as glass or carbon fibre reinforced polymers. These materials are a combination of two materials glass or carbon, mixed with a polymer. The material and component are manufactured simultaneously which make identifying material defects prior to component manufacture impossible. To identify such defects, components must be tested post manufacture. Similarly, these materials can become damaged during use, and therefore periodic inspections are important as defect result in reduced strength and stiffness. However the materials properties of most composite materials make non-destructive inspections using traditional techniques difficult.

One type of inspection technique that works well with thin composites (less the 1 mm thick) is thermography. It is a technique that can both identify defects, and also provide an image, informing the user about the size and location of the defect. This is particularly useful as not all defects are critical, small defects in a regions outside of the load path may not be important. In thermography, heat is applied to a material, and a thermal imaging camera is used to inspect the surface of the component. The heat transfer through the material will be disrupted by defects, and it is possible to observe this using the thermal imaging camera. However, polymers are typically insulating materials and do not conduct heat well. Therefore for thicker materials, thermography is of limited use, as the heat simply cannot conduct deep enough into the component. Experimental error also plays a role in reducing the depth at which defects can be identified. The current research has extended to the depth at which defects are identified by compensating for the experimental error. A novel processing routine has been developed which improves probing depth from approximately 1 mm to 1.8 mm (in the material tested - Glass fibre reinforced with epoxy resin). This allows for easier, more accurate characterization and identification of defects. This allows thermography to be used to in greater number of applications, and improves the results in existing applications.
Exploitation Route The technique developed can be used by anyone wishing to use thermography, but is of particular interest to those interested in thick composite materials. It is of interest to both academic and industrial groups.
Sectors Aerospace, Defence and Marine,Energy,Environment,Leisure Activities, including Sports, Recreation and Tourism,Manufacturing, including Industrial Biotechology,Transport

 
Title Processing of thermographic data for improved probing depth 
Description Non-destructive inspections by Pulse Thermography (PT) of composite materials is limited in terms of the depth that a defect can be identified by the low thermal diffusivity of most polymeric composite materials. The current research project has developed a novel processing procedure which can extend to the depth at which defects are identified by compensating for errors present in the raw thermal data. The procedure first compensates for vignette effects by recording pre-flash frames which can be subtracted from the data set. Non-uniformity due to flash heating are then compensated by first evaluating the non-uniformity, and then reversing it. Temporal noise is reduced using an existing technique developed by Shepard et al, called thermal signal reconstruction. The result of this processing is significantly reduced spatial and temporal error, and improve defect characterization and identification. The technique was expanded to Pulse Phase Thermography (PPT), which is an existing processing technique developed by Maldague and Marinetti 1996. The technique uses PT data and applies a fast fourier transform (FFT) to obtain phase data in the frequency domain. The existing procedure does not include any pre-processing of data. The novel contribution of the current work is to combine the thermal processing described above with PPT to reduce non-uniformity and errors in the PPT phase data. In addition the current research proposes the use of windowing functions to reduce spectral leakage when using the FFT. This step is important when probing depth is of interest as spectral leakage can otherwise obscure defects in the data. 
Type Of Material Data analysis technique 
Year Produced 2019 
Provided To Others? Yes  
Impact The processing method is published and can be used by anyone wishing to inspect thick composite materials. The methods described are of particular interest to other academic research groups, who may wish to use this processing technique to compensate for errors in data. It is also of interest to industry where the processing can be used to improve existing inspections or allow the inspection of components which cannot currently be assess with PT. 
 
Description STRUCTURES 2025: A HIGH FIDELITY, DATA RICH, PARADIGM FOR STRUCTURAL TESTING 
Organisation Airbus Group
Country France 
Sector Private 
PI Contribution Preforming pre-demonstrator experiments and data processing which will be used to demonstrate how a new laboratory (National Infrastructure Laboratory - part of Structures 2025 project) can be used. Attendance to all Industrial Advisory Board meetings, presenting progress on demonstrators, and participating in discussions and breakout sessions.
Collaborator Contribution Collaborators have enabled the building of a new laboratory (National Infrastructure Laboratory). The industrial partners offer two key contributions, firstly they advise on industrial challenges which they are seeking to overcome. Secondly, they help ensure research is applicable to industry and industrial needs. Academic partners offer the opportunity for future collaborations, and secondments.
Impact The completion of the National Infrastructure Laboratory.
Start Year 2017
 
Description STRUCTURES 2025: A HIGH FIDELITY, DATA RICH, PARADIGM FOR STRUCTURAL TESTING 
Organisation Arup Group
Country United Kingdom 
Sector Private 
PI Contribution Preforming pre-demonstrator experiments and data processing which will be used to demonstrate how a new laboratory (National Infrastructure Laboratory - part of Structures 2025 project) can be used. Attendance to all Industrial Advisory Board meetings, presenting progress on demonstrators, and participating in discussions and breakout sessions.
Collaborator Contribution Collaborators have enabled the building of a new laboratory (National Infrastructure Laboratory). The industrial partners offer two key contributions, firstly they advise on industrial challenges which they are seeking to overcome. Secondly, they help ensure research is applicable to industry and industrial needs. Academic partners offer the opportunity for future collaborations, and secondments.
Impact The completion of the National Infrastructure Laboratory.
Start Year 2017
 
Description STRUCTURES 2025: A HIGH FIDELITY, DATA RICH, PARADIGM FOR STRUCTURAL TESTING 
Organisation BAE Systems
Country United Kingdom 
Sector Private 
PI Contribution Preforming pre-demonstrator experiments and data processing which will be used to demonstrate how a new laboratory (National Infrastructure Laboratory - part of Structures 2025 project) can be used. Attendance to all Industrial Advisory Board meetings, presenting progress on demonstrators, and participating in discussions and breakout sessions.
Collaborator Contribution Collaborators have enabled the building of a new laboratory (National Infrastructure Laboratory). The industrial partners offer two key contributions, firstly they advise on industrial challenges which they are seeking to overcome. Secondly, they help ensure research is applicable to industry and industrial needs. Academic partners offer the opportunity for future collaborations, and secondments.
Impact The completion of the National Infrastructure Laboratory.
Start Year 2017
 
Description STRUCTURES 2025: A HIGH FIDELITY, DATA RICH, PARADIGM FOR STRUCTURAL TESTING 
Organisation BMT Group
Country United Kingdom 
Sector Private 
PI Contribution Preforming pre-demonstrator experiments and data processing which will be used to demonstrate how a new laboratory (National Infrastructure Laboratory - part of Structures 2025 project) can be used. Attendance to all Industrial Advisory Board meetings, presenting progress on demonstrators, and participating in discussions and breakout sessions.
Collaborator Contribution Collaborators have enabled the building of a new laboratory (National Infrastructure Laboratory). The industrial partners offer two key contributions, firstly they advise on industrial challenges which they are seeking to overcome. Secondly, they help ensure research is applicable to industry and industrial needs. Academic partners offer the opportunity for future collaborations, and secondments.
Impact The completion of the National Infrastructure Laboratory.
Start Year 2017
 
Description STRUCTURES 2025: A HIGH FIDELITY, DATA RICH, PARADIGM FOR STRUCTURAL TESTING 
Organisation EDF Energy
Country United Kingdom 
Sector Private 
PI Contribution Preforming pre-demonstrator experiments and data processing which will be used to demonstrate how a new laboratory (National Infrastructure Laboratory - part of Structures 2025 project) can be used. Attendance to all Industrial Advisory Board meetings, presenting progress on demonstrators, and participating in discussions and breakout sessions.
Collaborator Contribution Collaborators have enabled the building of a new laboratory (National Infrastructure Laboratory). The industrial partners offer two key contributions, firstly they advise on industrial challenges which they are seeking to overcome. Secondly, they help ensure research is applicable to industry and industrial needs. Academic partners offer the opportunity for future collaborations, and secondments.
Impact The completion of the National Infrastructure Laboratory.
Start Year 2017
 
Description STRUCTURES 2025: A HIGH FIDELITY, DATA RICH, PARADIGM FOR STRUCTURAL TESTING 
Organisation LaVision GmbH
Country Germany 
Sector Private 
PI Contribution Preforming pre-demonstrator experiments and data processing which will be used to demonstrate how a new laboratory (National Infrastructure Laboratory - part of Structures 2025 project) can be used. Attendance to all Industrial Advisory Board meetings, presenting progress on demonstrators, and participating in discussions and breakout sessions.
Collaborator Contribution Collaborators have enabled the building of a new laboratory (National Infrastructure Laboratory). The industrial partners offer two key contributions, firstly they advise on industrial challenges which they are seeking to overcome. Secondly, they help ensure research is applicable to industry and industrial needs. Academic partners offer the opportunity for future collaborations, and secondments.
Impact The completion of the National Infrastructure Laboratory.
Start Year 2017
 
Description STRUCTURES 2025: A HIGH FIDELITY, DATA RICH, PARADIGM FOR STRUCTURAL TESTING 
Organisation Lloyd's Register
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution Preforming pre-demonstrator experiments and data processing which will be used to demonstrate how a new laboratory (National Infrastructure Laboratory - part of Structures 2025 project) can be used. Attendance to all Industrial Advisory Board meetings, presenting progress on demonstrators, and participating in discussions and breakout sessions.
Collaborator Contribution Collaborators have enabled the building of a new laboratory (National Infrastructure Laboratory). The industrial partners offer two key contributions, firstly they advise on industrial challenges which they are seeking to overcome. Secondly, they help ensure research is applicable to industry and industrial needs. Academic partners offer the opportunity for future collaborations, and secondments.
Impact The completion of the National Infrastructure Laboratory.
Start Year 2017
 
Description STRUCTURES 2025: A HIGH FIDELITY, DATA RICH, PARADIGM FOR STRUCTURAL TESTING 
Organisation MTS Systems Corporation
PI Contribution Preforming pre-demonstrator experiments and data processing which will be used to demonstrate how a new laboratory (National Infrastructure Laboratory - part of Structures 2025 project) can be used. Attendance to all Industrial Advisory Board meetings, presenting progress on demonstrators, and participating in discussions and breakout sessions.
Collaborator Contribution Collaborators have enabled the building of a new laboratory (National Infrastructure Laboratory). The industrial partners offer two key contributions, firstly they advise on industrial challenges which they are seeking to overcome. Secondly, they help ensure research is applicable to industry and industrial needs. Academic partners offer the opportunity for future collaborations, and secondments.
Impact The completion of the National Infrastructure Laboratory.
Start Year 2017
 
Description STRUCTURES 2025: A HIGH FIDELITY, DATA RICH, PARADIGM FOR STRUCTURAL TESTING 
Organisation National Composites Centre (NCC)
Country United Kingdom 
Sector Private 
PI Contribution Preforming pre-demonstrator experiments and data processing which will be used to demonstrate how a new laboratory (National Infrastructure Laboratory - part of Structures 2025 project) can be used. Attendance to all Industrial Advisory Board meetings, presenting progress on demonstrators, and participating in discussions and breakout sessions.
Collaborator Contribution Collaborators have enabled the building of a new laboratory (National Infrastructure Laboratory). The industrial partners offer two key contributions, firstly they advise on industrial challenges which they are seeking to overcome. Secondly, they help ensure research is applicable to industry and industrial needs. Academic partners offer the opportunity for future collaborations, and secondments.
Impact The completion of the National Infrastructure Laboratory.
Start Year 2017
 
Description STRUCTURES 2025: A HIGH FIDELITY, DATA RICH, PARADIGM FOR STRUCTURAL TESTING 
Organisation National Physical Laboratory
Country United Kingdom 
Sector Academic/University 
PI Contribution Preforming pre-demonstrator experiments and data processing which will be used to demonstrate how a new laboratory (National Infrastructure Laboratory - part of Structures 2025 project) can be used. Attendance to all Industrial Advisory Board meetings, presenting progress on demonstrators, and participating in discussions and breakout sessions.
Collaborator Contribution Collaborators have enabled the building of a new laboratory (National Infrastructure Laboratory). The industrial partners offer two key contributions, firstly they advise on industrial challenges which they are seeking to overcome. Secondly, they help ensure research is applicable to industry and industrial needs. Academic partners offer the opportunity for future collaborations, and secondments.
Impact The completion of the National Infrastructure Laboratory.
Start Year 2017
 
Description STRUCTURES 2025: A HIGH FIDELITY, DATA RICH, PARADIGM FOR STRUCTURAL TESTING 
Organisation Network Rail Ltd
Country United Kingdom 
Sector Private 
PI Contribution Preforming pre-demonstrator experiments and data processing which will be used to demonstrate how a new laboratory (National Infrastructure Laboratory - part of Structures 2025 project) can be used. Attendance to all Industrial Advisory Board meetings, presenting progress on demonstrators, and participating in discussions and breakout sessions.
Collaborator Contribution Collaborators have enabled the building of a new laboratory (National Infrastructure Laboratory). The industrial partners offer two key contributions, firstly they advise on industrial challenges which they are seeking to overcome. Secondly, they help ensure research is applicable to industry and industrial needs. Academic partners offer the opportunity for future collaborations, and secondments.
Impact The completion of the National Infrastructure Laboratory.
Start Year 2017
 
Description STRUCTURES 2025: A HIGH FIDELITY, DATA RICH, PARADIGM FOR STRUCTURAL TESTING 
Organisation Offshore Renewable Energy Catapult
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution Preforming pre-demonstrator experiments and data processing which will be used to demonstrate how a new laboratory (National Infrastructure Laboratory - part of Structures 2025 project) can be used. Attendance to all Industrial Advisory Board meetings, presenting progress on demonstrators, and participating in discussions and breakout sessions.
Collaborator Contribution Collaborators have enabled the building of a new laboratory (National Infrastructure Laboratory). The industrial partners offer two key contributions, firstly they advise on industrial challenges which they are seeking to overcome. Secondly, they help ensure research is applicable to industry and industrial needs. Academic partners offer the opportunity for future collaborations, and secondments.
Impact The completion of the National Infrastructure Laboratory.
Start Year 2017
 
Description STRUCTURES 2025: A HIGH FIDELITY, DATA RICH, PARADIGM FOR STRUCTURAL TESTING 
Organisation Royal National Lifeboat Institution
Country United Kingdom 
Sector Public 
PI Contribution Preforming pre-demonstrator experiments and data processing which will be used to demonstrate how a new laboratory (National Infrastructure Laboratory - part of Structures 2025 project) can be used. Attendance to all Industrial Advisory Board meetings, presenting progress on demonstrators, and participating in discussions and breakout sessions.
Collaborator Contribution Collaborators have enabled the building of a new laboratory (National Infrastructure Laboratory). The industrial partners offer two key contributions, firstly they advise on industrial challenges which they are seeking to overcome. Secondly, they help ensure research is applicable to industry and industrial needs. Academic partners offer the opportunity for future collaborations, and secondments.
Impact The completion of the National Infrastructure Laboratory.
Start Year 2017
 
Description STRUCTURES 2025: A HIGH FIDELITY, DATA RICH, PARADIGM FOR STRUCTURAL TESTING 
Organisation Shell International Petroleum
Country United Kingdom 
Sector Private 
PI Contribution Preforming pre-demonstrator experiments and data processing which will be used to demonstrate how a new laboratory (National Infrastructure Laboratory - part of Structures 2025 project) can be used. Attendance to all Industrial Advisory Board meetings, presenting progress on demonstrators, and participating in discussions and breakout sessions.
Collaborator Contribution Collaborators have enabled the building of a new laboratory (National Infrastructure Laboratory). The industrial partners offer two key contributions, firstly they advise on industrial challenges which they are seeking to overcome. Secondly, they help ensure research is applicable to industry and industrial needs. Academic partners offer the opportunity for future collaborations, and secondments.
Impact The completion of the National Infrastructure Laboratory.
Start Year 2017
 
Description STRUCTURES 2025: A HIGH FIDELITY, DATA RICH, PARADIGM FOR STRUCTURAL TESTING 
Organisation Siemens AG
Country Germany 
Sector Private 
PI Contribution Preforming pre-demonstrator experiments and data processing which will be used to demonstrate how a new laboratory (National Infrastructure Laboratory - part of Structures 2025 project) can be used. Attendance to all Industrial Advisory Board meetings, presenting progress on demonstrators, and participating in discussions and breakout sessions.
Collaborator Contribution Collaborators have enabled the building of a new laboratory (National Infrastructure Laboratory). The industrial partners offer two key contributions, firstly they advise on industrial challenges which they are seeking to overcome. Secondly, they help ensure research is applicable to industry and industrial needs. Academic partners offer the opportunity for future collaborations, and secondments.
Impact The completion of the National Infrastructure Laboratory.
Start Year 2017