Category Archives: INSTRUCTIVE project

Archive video footage from EU projects

This week I am in the US presenting work from our EU projects INSTRUCTIVE and MOTIVATE at the Annual Conference and Exposition of the Society for Experimental Mechanics.  Although the INSTRUCTIVE project was completed at the end of December 2018, the process of disseminating and exploiting the research will go on for some time.  The capability to identify the initiation of cracks when they are less than 1mm long and to track their propagation is a key piece of technology for DIMES project in which we are developing an integrated system for monitoring the condition of aircraft structures.  We are in the last twelve months of the MOTIVATE project and we have started producing video clips about the technology that is being developed.  So, if you missed my presentations at the conference in the US then you can watch the videos online using the links below 😉.

We have been making videos describing the outputs of our EU project for about 20 years; so, if you want to see some vintage footage of me twenty years younger then watch a video from the INDUCE project that was active from 1998 to 2001.

MOTIVATE videos: Introduction; Industrial calibration of DIC measurements using a calibration plate or using an LCD screen

The MOTIVATE project has received funding from the Clean Sky 2 Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 754660.

Image: Peppermill Hotel in Reno, Nevada where the conference is being held.


Finding DIMES

A couple of weeks ago I wrote about the ‘INSTRUCTIVE final reckoning’ (see post on January 9th).  INSTRUCTIVE was an EU project, which ended on December 31st, 2018  in which we demonstrated that infra-red cameras could be used to monitor the initiation and propagation of cracks in aircraft structures (see Middleton et al, 2019).  Now, we have seamlessly moved on to a new EU project, called DIMES (Development of Integrated MEasurement Systems), which started on January 1st, 2019.  To quote our EU documentation, the overall aim of DIMES is ‘to develop and demonstrate an automated measurement system that integrates a range of measurement approaches to enable damage and cracks to be detected and monitored as they originate at multi-material interfaces in an aircraft assembly’.  In simpler terms, we are going to take the results from the INSTRUCTIVE project, integrate them with other existing technologies for monitoring the structural health of an aircraft, and produce a system that can be installed in an aircraft fuselage and will provide early warning on the formation of cracks.  We have two years to achieve this target and demonstrate the system in a ground-based test on a real fuselage at an Airbus facility.  This was a scary prospect until we had our kick-off meeting and a follow-up brainstorming session a couple of weeks ago.  Now, it’s a little less scary.  If I have scared you with the prospect of cracks in aircraft, then do not be alarmed; we have been flying aircraft with cracks in them for years.  It is impossible to build an aircraft without cracks appearing, possibly during manufacturing and certainly in service – perfection (i.e. cracklessness) is unattainable and instead the stresses are maintained low enough to ensure undetected cracks will not grow (see ‘Alan Arnold Griffith’ on April 26th, 2017) and that detected ones are repaired before they propagate significantly (see ‘Aircraft inspection’ on October 10th, 2018).

I should explain that the ‘we’ above is the University of Liverpool and Strain Solutions Limited, who were the partners in INSTRUCTIVE, plus EMPA, the Swiss National Materials Laboratory, and Dantec Dynamics GmbH, a producer of scientific instruments in Ulm, Germany.  I am already working with these latter two organisations in the EU project MOTIVATE; so, we are a close-knit team who know and trust each other  – that’s one of the keys to successful collaborations tackling ambitious challenges with game-changing outcomes.

So how might the outcomes of DIMES be game-changing?  Well, at the moment, aircraft are designed using computer models that are comprehensively validated using measurement data from a large number of expensive experiments.  The MOTIVATE project is about reducing the number of experiments and increasing the quality and quantity of information gained from each experiment, i.e. ‘Getting Smarter’ (see post on June 21st 2017).  However, if the measurement system developed in DIMES allowed us to monitor in-flight strain fields in critical locations on-board an aircraft, then we would have high quality data to support future design work, which would allow further reductions in the campaign of experiments required to support new designs; and we would have continuous comprehensive monitoring of the structural integrity of every aircraft in the fleet, which would allow more efficient planning of maintenance as well as increased safety margins, or reductions in structural weight while maintaining safety margins.  This would be a significant step towards digital twins of aircraft (see ‘Fourth industrial revolution’ on July 4th, 2018 and ‘Can you trust your digital twin?’ on November 23rd, 2016).

The INSTRUCTIVE, MOTIVATE and DIMES projects have received funding from the Clean Sky 2 Joint Undertaking under the European Union’s Horizon 2020 research and innovation programme under grant agreements No. 685777, No. 754660 and No. 820951 respectively.

The opinions expressed in this blog post reflect only the author’s view and the Clean Sky 2 Joint Undertaking is not responsible for any use that may be made of the information it contains.


Middleton CA, Gaio A, Greene RJ & Patterson EA, Towards automated tracking of initiation and propagation of cracks in Aluminium alloy coupons using thermoelastic stress analysis, J. Non-destructive Testing, 38:18, 2019


INSTRUCTIVE final reckoning

Our EU project, INSTRUCTIVE came to an end with the closing of 2018.  We have achieved all of our milestones and deliverables; and, now have 51 (=60-9) days to submit our final reports.  We have already presented the technical contents of those reports to representatives of our sponsors in a final review meeting just before the Christmas break.  I think that they were pleased with our progress; our findings certainly stimulated debate about how to move forward and implement the new technologies – lots of new questions that we did not know we should be asking when we started the project.

We are also disseminating the key results more publicly because this is an obligation inherent with receiving public funding for our research; but also, because I see no purpose in advancing knowledge without sharing it. During the course of the project we have given research updates at three conferences and the papers/abstracts for these are available via the University of Liverpool Repository [#1, #2 & #3].  And, we are in the process of producing three papers for publication in archived journals.

However, the real tangible benefit of the project is the move to next stage of development for the technology supported by a new project, called DIMES, that started on January 1st, 2019.  The aim of the DIMES project is to develop and demonstrate systems with the capability to detect a crack or delamination in a metallic or composite structure, and the potential to be deployed as part of an on-board structural health monitoring system for passenger aircraft.  In other words, the INSTRUCTIVE project has successfully demonstrated that a new philosophy for monitoring damage in aerospace structures, using disturbances to the strain field caused by the damage, is at least as effective as traditional non-destructive evaluation (NDE) techniques and in some circumstances provides much more sensitivity about the initiation and propagation of damage.  This has been sufficiently successful in the laboratory and on aircraft components in an industrial environment that is worth exploring its deployment for on-board monitoring and the first step is to use it in ground-based tests.

There will be more on DIMES as the project gets underway and updates on its progress will replace the twice-yearly ones on INSTRUCTIVE.

The series of posts on the INSTRUCTIVE project can be found at

instructive acknowledgement

Aircraft inspection

A few months I took this series of photographs while waiting to board a trans-Atlantic flight home.  First, a small ladder was placed in front of the engine.  Then a technician arrived, climbed onto the ladder and spread a blanket on the cowling before kneeling on it and spinning the fan blades slowly.  He must have spotted something that concerned him because he climbed in, lay on the blanket and made a closer inspection.  Then he climbed down, rolled up the blanket and left.  A few minutes later he returned with a colleague, laid out the blanket and they both had a careful look inside the engine, after which they climbed down, rolled up the blanket put it back in a special bag and left.  Five or ten minutes later, they were back with a third colleague.  The blanket was laid out again, the engine inspected by two of them at once and a three-way discussion ensued.  The result was that our flight was postponed while the airline produced a new plane for us.

Throughout this process it appeared that the most sophisticated inspection equipment used was the human eye and a mobile phone.  I suspect that the earlier inspections were reported by phone to the supervisor who came to look for himself before making the decision.  One of the goals of our current research is to develop easy-to-use instrumentation that could be used to provide more information about the structural integrity of components in this type of situation.  In the INSTRUCTIVE project we are investigating the use of low-cost infra-red cameras to identify incipient damage in aerospace structures.  Our vision is that the sort of inspection described above could be performed using an infra-red camera that would provide detailed data about the condition of the structure.  This data would update a digital twin that, in turn, would provide a prognosis for the structure.  The motivation is to improve safety and reduce operating costs by accurate identification of critical damage.