Category Archives: MOTIVATE 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.

 

In Einstein’s footprints?

Grand Hall of the Guild of Carpenters, Zurich

During the past week, I have been working with members of my research group on a series of papers for a conference in the USA that a small group of us will be attending in the summer.  Dissemination is an important step in the research process; there is no point in doing the research if we lock the results away in a desk drawer and forget about them.  Nowadays, the funding organisations that support our research expect to see a plan of dissemination as part of our proposals for research; and hence, we have an obligation to present our results to the scientific community as well as to communicate them more widely, for instance through this blog.

That’s all fine; but nevertheless, I don’t find most conferences a worthwhile experience.  Often, there are too many uncoordinated sessions running in parallel that contain presentations describing tiny steps forward in knowledge and understanding which fail to compel your attention [see ‘Compelling presentations‘ on March 21st, 2018].  Of course, they can provide an opportunity to network, especially for those researchers in the early stages of their careers; but, in my experience, they are rarely the location for serious intellectual discussion or debate.  This is more likely to happen in small workshops focussed on a ‘hot-topic’ and with a carefully selected eclectic mix of speakers interspersed with chaired discussion sessions.

I have been involved in organising a number of such workshops in Glasgow, London, Munich and Shanghai over the last decade.  The next one will be in Zurich in November 2019 in Guild Hall of Carpenters (Zunfthaus zur Zimmerleuten) where Einstein lectured in November 1910 to the Zurich Physical Society ‘On Boltzmann’s principle and some of its direct consequences‘.  Our subject will be different: ‘Validation of Computational Mechanics Models’; but we hope that the debate on credible models, multi-physics simulations and surviving with experimental data will be as lively as in 1910.  If you would like to contribute then download the pdf from this link; and if you just like to attend the one-day workshop then we will be announcing registration soon and there is no charge!

We have published the outcomes from some of our previous workshops:

Advances in Validation of Computational Mechanics Models (from the 2014 workshop in Munich), Journal of Strain Analysis, vol. 51, no.1, 2016

Strain Measurement in Extreme Environments (from the 2012 workshop in Glasgow), Journal of Strain Analysis, vol. 49, no. 4, 2014.

Validation of Computational Solid Mechanics Models (from the 2011 workshop in Shanghai), Journal of Strain Analysis, vol. 48, no.1, 2013.

The workshop is supported by the MOTIVATE project and further details are available at http://www.engineeringvalidation.org/4th-workshop

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.

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.

Sources:

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

 

Industrial uncertainty

Last month I spent almost a week in Zurich.  It is one of our favourite European cities [see ‘A reflection of existentialism‘ on December 20th, 2017]; however, on this occasion there was no time for sight-seeing because I was there for the mid-term meeting of the MOTIVATE project and to conduct some tests and demonstrations in the laboratories of our host, EMPA, the Swiss Federal Laboratories for Materials Science and Technology.  Two of our project partners, Dantec Dynamics GmbH based in Ulm, Germany, and the Athena Research Centre in Patras, Greece, have developed methods for quantifying the uncertainty present in measurements of deformation made in an industrial environment using digital image correlation (DIC) [see ‘256 shades of grey‘ on January 22, 2014].  Digital image correlation is a technique in which we usually apply a random speckle pattern to the object which allows us to track the movement of the object surface over time by searching for the new position of the speckles in the photographs of the object.  If we use a pair of cameras in a stereoscopic arrangement, then we can measure in-plane and out-of-plane displacements.  Digital image correlation is a well-established measurement technique that has become ubiquitous in mechanics laboratories. In previous EU projects, we have developed technology for quantifying uncertainty in in-plane [SPOTS project] and out-of-plane [ADVISE project] measurements in a laboratory environment.  However, when you take the digital image correlation equipment into an industrial environment, for instance an aircraft hangar to make measurements during a full-scale test, then additional sources of uncertainty and error appear. The new technology demonstrated last month allows these additional uncertainties to be quantified.  As part of the MOTIVATE project, we will be involved in a full-scale test on a large section of an Airbus aircraft next year and so, we will be able to utilise the new technology for the first time.

The photograph shows preparations for the demonstrations in EMPA’s laboratories.  In the foreground is a stereoscopic digital image correlation system with which we are about to make measurements of deformation of a section of aircraft skin, supplied by Airbus, which has a speckle pattern on its surface and is about to be loaded in compression by the large servo-hydraulic test machine.

References:

From SPOTS project:

Patterson EA, Hack E, Brailly P, Burguete RL, Saleem Q, Seibert T, Tomlinson RA & Whelan M, Calibration and evaluation of optical systems for full-field strain measurement, Optics and Lasers in Engineering, 45(5):550-564, 2007.

Whelan MP, Albrecht D, Hack E & Patterson EA, Calibration of a speckle interferometry full-field strain measurement system, Strain, 44(2):180-190, 2008.

From ADVISE project:

Hack E, Lin X, Patterson EA & Sebastian CM, A reference material for establishing uncertainties in full-field displacement measurements, Measurement Science and Technology, 26:075004, 2015.