Numerical simulation in aeronautics
15-05-2019 | Posted by Principia
Eduardo Oslé is an Aeronautical Engineer at Airbus. He specialises in finite element analysis of structures, has some 30 years of experience in aeronautical firms, and collaborates in academic activities such as the Master in Composite Materials of the UPM (Universidad Politécnica de Madrid) or the Master in Airframe Technology of the UC3M (Universidad Carlos III de Madrid). He tells us about the impact of numerical simulation in aeronautics and comments on how sometimes words manage to express concepts that eventually result in innovation. But what is the reality behind the fashionable concepts?
Principia: We are currently introducing many words associated with technology; some will stay, some will not. How have fashionable concepts evolved in your area?
Eduardo Oslé (E.O.): Each period has its fashionable concepts. They go in cycles, at times associated with technologies, other times with working procedures, with how a company is organised. In our area, many reflect the application or formulation of common sense to something, like for example organisation of engineering, reengineering, concurrent engineering. Or when we heard about “lean” processes or, more recently, about “agile” and “scrum” methodologies.
I would like to recall the counterpoint provided by the Dilbert comics (of the Dilbert Principle), which constantly quote this type of trendy words, concepts that emerge year after year and that, taken to the extreme, become a representation of the absurd.
Don’t they lose some of their meaning through overuse?
I believe they are meaningful in that they activate some processes, but at times they lose part of their value for the engineering community. New concepts, new dynamics, which are fine if you don’t take them too strictly, as a goal in themselves, instead of applying common sense. In the context of technology those trendy words may represent new concepts that emerge at a given time, change rapidly and eventually disappear. Others, however, are here to stay.
The words create the trend or is it the trend that coins the words…
Good question, but I believe the answer is both. Sometimes a fashionable word may create a trend because it is sufficiently powerful to affect budgets, to trigger investment in a certain technology, and hence to add a capacity to develop it beyond what otherwise would have been.
For example, the concept of “additive manufacturing” or “3D printing” has led companies to invest in technological institutes, causing the technology to develop faster than it would have without the resources that the fashionable term has contributed. But in other cases the result has not been the same.
Artificial intelligence (AI) is a concept born long ago, somewhat wide and vague, but which helps to develop more concrete trends such as “data mining” or “machine learning”, which are essential for AI.
In our latest users’ meeting you talked about the magnification curve… Could you comment on what it is, what it measures and why did you mention it.
The magnification curve measures, or attempts to measure, the expectations raised by a technology over time. It is just qualitative. At some point most technologies raise the expectation that they will be a panacea solving all our problems. With the passage of time those expectations tend to decrease and, at best, we may recover some of them and will actually be realised; it is the case, for example, of Segway, the electric self-balancing transporter that looked as if it were going to solve all mobility problems and that now has resurfaced as a scooter or hoverboard with other types of applications.
At the company level, we must be prepared, investing from industry within our possibilities, and always alert to decide how and when it must be incorporated into our business. Briefly, the magnification curve shows that we must keep track of technologies to see how they evolve, or to notice that not all trendy words end up providing a real application to our products.
How do you apply simulation from design to delivery?
In the area of structures we use numerical simulation from the conceptual stage, to the design phase, entry into service and through the end of the useful life. At the conceptual stage the models are far simpler, we have less information and the uncertainties are greater; the models are more conceptual, more basic and faster to execute.
As the design of the product progresses, our simulation becomes more sophisticated, we refine the loading conditions with more detailed designs and our models become more complex until we reach the certification stage, which involves the highest levels of complexity. Afterwards we use simulation continuously throughout the useful life to analyse possible improvements or problems experienced.
What are now the trendy words in simulation?
Among the trendy words in simulation we have “virtual testing” or “smart testing”, which are used to refer to many types of analysis. Other examples are “data mining”, “data analytics”, “machine learning”, and all the words associated with “big data” or the processing of large amounts of information.
An interesting one is “model-based systems engineering”, now a very popular expression, although to some extent we have already been applying it for some time. An there is the “digital twin”, the digital equivalent of a physical specimen, which provides all the information, in our case, about our planes or other products.
How do you conceive the “model-based systems engineering” at Airbus? And how do you apply it?
“Model-based systems engineering”, in principle, is more oriented to systems engineering; in structures, we use it in certain processes to provide some tools, in our case for validation and verification of simulations, which are common with the area of Engineering. But it still has many unexplored possibilities.
There are also associated terms, like “multi-physics modelling” or “multi-model representation”, which refer to representing different physics with a single model, or to a structure or component using different models or representations to deal with the various physics involved.
What simulation improvements do you believe are necessary to foster innovation in industrial manufacturing?
One of the areas for future improvement is the training of our engineers. It is essential that they have the training, experience and critical thinking for understanding the implications of simulation, which will become progressively more complex. We need engineers who can interpret the simulation correctly, as it becomes conceptually more complex while simplifying the development of products..
The tools being made available by the software industry are increasingly powerful and we will be able to generate ever more sophisticated models, but we must count on staff able to interpret the results and to derive physical meaning from the mathematical information.
And who is in charge?
Industry, university, our present and future engineers must be capable of not just modelling, but of being able to interpret the results of the simulation.
Do you think simulation will have a relevant role in the future of the industrial sector?
Yes, it has it now and will have it even more.
The objective is to generate products that are safer, more reliable and that cost less, and simulation helps to achieve this.
Moreover, users would like to reduce the maintenance costs in the aeronautics or automotive sectors. As simulation develops, it contributes solutions to the questions of cost reduction and safety improvement.
What contribution of simulation would you highlight in your area?
The finite element method is a contribution from the 50´s or 60’s, but it has been a fundamental one. It is a very flexible and versatile tool that powered the development of aeronautics first and then of other applied sciences such as mechanical engineering or biomedical sciences. It is a method that, because of its simplicity and ease of application, has led to many advances, many more than initially foreseen.