Category Archives: Engineering

Did cubism inspire engineering analysis?

Bottle and Fishes c.1910-2 Georges Braque 1882-1963 Purchased 1961 http://www.tate.org.uk/art/work/T00445

Bottle and Fishes c.1910-2 Georges Braque 1882-1963 Purchased 1961 http://www.tate.org.uk/art/work/T00445

A few weeks ago we went to the Tate Liverpool with some friends who were visiting from out of town. It was my second visit to the gallery in as many months and I was reminded that on the previous visit I had thought about writing a post on a painting called ‘Bottle and Fishes’ by the French artist, Georges Braque.  It’s an early cubist painting – the style was developed by Picasso and Braque at the beginning of the last century.  The art critic, Louis Vauxcelles coined the term ‘cubism’ on seeing some of Braque’s paintings in 1908 and describing them as reducing everything to ‘geometric outlines, to cubes’.  It set me thinking about how long it took the engineering world to catch on to the idea of reducing objects, or components and structures, to geometric outlines and then into cubes.  This is the basis of finite element analysis, which was not invented until about fifty years after cubism, but is now ubiquitous in engineering design as the principal method of calculating deformation and stresses in components and structures.  An engineer can calculate the stresses in a simple cube with a pencil and paper, so dividing a structure into a myriad of cubes renders its analysis relatively straightforward but very tedious.  Of course, a computer removes the tedium and allows us to analyse complex structures relatively quickly and reliably.

So, why did it take engineers fifty years to apply cubism?  Well, we needed computers sufficiently powerful to make it worthwhile and they only became available after the Second War World due to the efforts of Turing and his peers.  At least, that’s our excuse!  Nowadays the application of finite element analysis extends beyond stress fields to many field variables, including heat, fluid flow and magnetic fields.

Can you trust your digital twin?

Author's digital twin?

Author’s digital twin?

There is about a 3% probability that you have a twin. About 32 in 1000 people are one of a pair of twins.  At the moment an even smaller number of us have a digital twin but this is the direction in which computational biomedicine is moving along with other fields.  For instance, soon all aircraft will have digital twins and most new nuclear power plants.  Digital twins are computational representations of individual members of a population, or fleet, in the case of aircraft and power plants.  For an engineering system, its computer-aided design (CAD) is the beginning of its twin, to which information is added from the quality assurance inspections before it leaves the factory and from non-destructive inspections during routine maintenance, as well as data acquired during service operations from health monitoring.  The result is an integrated model and database, which describes the condition and history of the system from conception to the present, that can be used to predict its response to anticipated changes in its environment, its remaining useful life or the impact of proposed modifications to its form and function. It is more challenging to create digital twins of ourselves because we don’t have original design drawings or direct access to the onboard health monitoring system but this is being worked on. However, digital twins are only useful if people believe in the behaviour or performance that they predict and are prepared to make decisions based on the predictions, in other words if the digital twins possess credibility.  Credibility appears to be like beauty because it is in eye of the beholder.  Most modellers believe that their models are both beautiful and credible, after all they are their ‘babies’, but unfortunately modellers are not usually the decision-makers who often have a different frame of reference and set of values.  In my group, one current line of research is to provide metrics and language that will assist in conveying confidence in the reliability of a digital twin to non-expert decision-makers and another is to create methodologies for evaluating the evidence prior to making a decision.  The approach is different depending on the extent to which the underlying models are principled, i.e. based on the laws of science, and can be tested using observations from the real world.  In practice, even with principled, testable models, a digital twin will never be an identical twin and hence there will always be some uncertainty so that decisions remain a matter of judgement based on a sound understanding of the best available evidence – so you are always likely to need advice from a friendly engineer   🙂

Sources:

De Lange, C., 2014, Meet your unborn child – before it’s conceived, New Scientist, 12 April 2014, p.8.

Glaessgen, E.H., & Stargel, D.S., 2012, The digital twin paradigm for future NASA and US Air Force vehicles, Proc 53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference, AIAA paper 2012-2018, NF1676L-13293.

Patterson E.A., Feligiotti, M. & Hack, E., 2013, On the integration of validation, quality assurance and non-destructive evaluation, J. Strain Analysis, 48(1):48-59.

Patterson, E.A., Taylor, R.J. & Bankhead, M., 2016, A framework for an integrated nuclear digital environment, Progress in Nuclear Energy, 87:97-103.

Patterson EA & Whelan MP, 2016, A framework to establish credibility of computational models in biology, Progress in Biophysics & Molecular Biology, doi: 10.1016/j.pbiomolbio.2016.08.007.

Tuegel, E.J., 2012, The airframe digital twin: some challenges to realization, Proc 53rd AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference.

Happenstance, not engineering?

okemos-art-2extract

A few weeks ago I wrote that ‘engineering is all about ingenuity‘ [post on September 14th, 2016] and pointed out that while some engineers are involved in designing, manufacturing and maintaining engines, most of us are not.  So, besides being ingenious, what do the rest of us do?  Well, most of us contribute in some way to the conception, building and sustaining of networks.  Communication networks, food supply networks, power networks, transport networks, networks of coastal defences, networks of oil rigs, refineries and service stations, or networks of mines, smelting works and factories that make everything from bicycles to xylophones.  The list is endless in our highly networked society.  A network is a group of interconnected things or people.  And, engineers are responsible for all of the nodes in our networks of things and for just about all the connections in our networks of both things and people.

Engineers have been constructing networks by building nodes and connecting them for thousands of years, for instance the ancient Mesopotamians were building aqueducts to connect their towns with distance water supplies more than four millenia ago.

Engineered networks are so ubiquitous that no one notices them until something goes wrong, which means engineers tend to get blamed more than praised.  But apparently that is the fault of the ultimate network: the human brain.  Recent research has shown that blame and praise are assigned by different mechanisms in the brain and that blame can be assigned by every location in the brain responsible for emotion whereas praise comes only from a single location responsible for logical thought.  So, we blame more frequently than we praise and we tend to assume that bad things are deliberate while good things are happenstance.  So reliable networks are happenstance rather than good engineering in the eyes of most people!

Sources:

Ngo L, Kelly M, Coutlee CG, Carter RM , Sinnott-Armstrong W & Huettel SA, Two distinct moral mechanisms for ascribing and denying intentionality, Scientific Reports, 5:17390, 2015.

Bruek H, Human brains are wired to blame rather than to praise, Fortune, December 4th 2015.

 

Art and engineering

Windows of the Soul II [3D video art installation: http://www.haigallery.com/sonia-falcone/]

Windows of the Soul II [3D video art installation: http://www.haigallery.com/sonia-falcone/%5D

A couple of weeks ago I wrote about the meaning of the words ‘engineer’ and ‘engineering’ [see my post entitled ‘Engineering is all about ingenuity‘ on September 14th, 2016] .  And it was clear that most engineers are involved in some sort of creative activity.  One of the common skills that unites the many different types of engineering is creative problem-solving.  But in that case how are engineers different from artists who are also involved in creative acts?  David Blockley summarises it succinctly as engineers produce something useful and artists produce something extraordinary.  Of course, very occasionally we manage to do both and an artist-engineer produces something extraordinary that is also useful.  I say ‘very occasionally’ because extraordinary implies it is exceptional, which eliminates mass-produced artifacts. It is difficult to identify modern creations that fit this description – the Large Hadron Collider is an extraordinary piece of engineering but is it art?  It is a product of the application of human skill and imagination, which is another definition of art.  Or the Solar Impulse – the solar powered plane that flew around the world?

On the other hand, when we visit art galleries we can buy prints and postcards that are copies of the artworks displayed in the gallery. Is the mass-produced, but iconic, engineering artifact equivalent to an art print? Perhaps the original has to be rather less transitory than the latest model of phone or car.  The advent of computer-aided engineering and rapid prototyping means that the original often only exists in virtual space, which is more equivalent to the video installations that are becoming more commonplace in galleries, such as Sonia Falcone’s ‘Best Video Installation Art at the Biennale in Santa Cruz Bolivia‘.