Structural Analysis Becomes Dynamic Professor Roland Wüchner is the new Head of the Institute of Structural Analysis and Dynamics

How does structural analysis become dynamic? What is wind engineering? What changes due to extreme weather events? And what is a simulation laboratory? That’s what we wanted to know from Professor Roland Wüchner, who heads the Institute of Structural Analysis and Dynamics (ISD). He succeeded the long-time director, Professor Dieter Dinkler, on 1 September. Bianca Loschinsky and Heiko Jacobs met Professor Wüchner at the institute on Beethovenstraße, which is currently being renovated.

Professor Wüchner, have you settled in well at TU Braunschweig?

The faculty and the entire team at the ISD gave me a really great welcome and made sure that the transition was seamless. It was a very good start and we have a great team spirit at the ISD. I also received great support from my predecessor Professor Dieter Dinkler, but also from the administration. A big thank you to everyone! I feel very welcome here.

You previously researched and taught at TU Munich. Why did you decide on TU Braunschweig?

With my profile, there is a very interesting environment here. I am a civil engineer with a focus on numerical simulation, which means “computational mechanics”. Especially in this combination, I have a very exciting field of connection at TU Braunschweig. There is the civil engineering degree programme here, quite classical. But there is also the Computational Sciences in Engineering (CSE) programme. This is an international Master’s programme that has great potential. The combination of state-of-the-art simulation methods with the challenges and issues of civil engineering is a good basis for generating innovative solutions.

In the Core Research Area “Future City”, for example, we can look at the consequences of climate change, which is a huge field of activity for us civil engineers. We can contribute to the protection of people, for example through suitable construction methods or a better understanding of stress scenarios.

In addition, infrastructure and the built environment are changing. We have new materials, construction methods and manufacturing processes. This is where the Collaborative Research Centre TRR277 “Additive Manufacturing in Construction (AMC)” comes into focus. It is part of the structural analysis and dynamics mission to be involved there as well.

On the other hand, in construction we also have to deal with the ageing of structures. Here, the Research Training Group 2075 has established itself, in which the ISD is integrated. Numerical simulation can do an incredible amount in the evaluation of changes in condition, for example through forecasts and digital twins. These are the major topics that I would like to address. I see the combination of civil engineering, socially relevant topics and the potential of simulation and modelling techniques as being very well established at TU Braunschweig.

Under your predecessor, the institute was called the “Institute of Structural Analysis” (Institut für Statik); when you took over, it was renamed the “Institute of Structural Analysis and Dynamics” ()nstitut für Statik und Dynamik). “Statik” has such a nice ring to it: permanence, immutability, security, certainty. Is that no longer appropriate in our dynamic present, even if many would like it to be?

Yes, we have added to the dedication, but nothing has changed in terms of the fundamental goals. “Statik” is a traditional brand: it researches and works on providing reliable analysis and assessment methods for load-bearing structures under the most diverse load scenarios. This can also be a dynamic load case such as wind, an earthquake or the like, and then “statics” becomes dynamic. The conceptual extension of the institute’s denomination now provides more clarity to the outside world and unmistakably expresses what “statics” has always been about: It is the link and the central interface between the basic disciplines and, above all, the constructional subjects.

The ISD draws very strongly on the tradition of the disciplines, but we also look to the future in a very focussed way. Today, we have state-of-the-art computer-based simulation methods to ensure the certainty of load-bearing capacity even for complex issues.

You are now literally bringing a breath of fresh air into the subject. Wind engineering is one of your main research areas. What exactly is behind it?

This topic has occupied me since my doctorate. Wind engineering is the rational description of the processes in the lower part of the atmosphere. In technical jargon, we call it the atmospheric boundary layer. That’s where our structures are located and that’s where we are. From the point of view of structural analysis, the interaction of natural wind flow and the mechanical behaviour of the supporting structures is particularly interesting, i.e. whether, for example, a bridge is prompted into making significant, disastrous vibrations or a building roof can withstand a strong storm.

Overall, wind engineering is an incredibly interesting, highly interdisciplinary discipline. It ranges from meteorology to fluid mechanics and even to structural analysis, with the individual fields being strongly intertwined.

Wind engineering has become even more important in recent years due to the trend towards lightweight construction and ever larger spans. We have greater flexibility in the supporting structures, which means they can also be stimulated to deform by the natural wind, which is then referred to as fluid-structure interaction (FSI). I would like to establish this as a focus here at the Institute.

On the one hand, we have the major challenges – lighter construction and extreme weather events – and on the other hand, with numerical simulation, new possibilities are available for recording the phenomena that occur. This is being researched and implemented in the still quite young sub-discipline of so-called “Computational Wind Engineering” (CWE) and will become a further focus at the ISD. The computer-aided investigations in wind engineering represent a clear expansion of the established procedures, such as the classic wind tunnel tests.

Keyword “extreme weather events”: The changes and influences caused by ageing, weather, climate, etc. have always been part of the structural calculations, haven’t they?

Yes, they have: Structures have always had to safely withstand the surrounding nature with its diverse load cases. But the extreme load scenarios that have become more dominant in the meantime, among other things as a result of climate change, have to be taken into account even more. A pyramid in Egypt will not move much in the face of storm loads, but it’s a different story for a long-span suspension bridge. In other words, extreme weather events and new construction methods present us with new tasks.

We have to be prepared to deal with even more violent structural reactions in the future. We can respond to these new challenges by using the potential of numerical simulation in a targeted manner. Today, we have an unprecedented range of modelling depth to capture structures and their changes. By linking numerical simulation and built-in sensor technology, we could generate the digital twin for structures and always keep it up-to-date, thus providing predictive analysis options.

Is all statics the same? Or how should civil engineers be trained today? How much classical fundamentals with pencil and calculator will still stand next to computer-aided mechanical calculations?

We keep circling back to the fact that we have the enormous possibilities offered by modern numerical simulation or even the available computer hardware in engineering offices, which indeed requires a solid knowledge in this area as well and thus must find its way into the modern teaching of statics.

To use these computer-based methods in practice means that as an engineer I need great expertise and modelling skills as well as a high sense of responsibility. As an engineer, you don’t hand over responsibility to the computer. This means that in addition to the methodological competence for simulation procedures, it is also important to have an excellent feeling for the load-bearing behaviour of constructions. So as an engineer, I must have a feeling for how constructions derive loads. Likewise, I must have the ability to control the simulations.

That’s why both the computer-oriented calculation methods – especially with the CSE degree programme – and the classical structural methods are an integral part of the teaching, because they have a very specific didactic purpose. On the one hand, the finished engineers can use them to make rough check calculations. On the other hand, the classical structural methods contribute to the students’ understanding of force flow and deformation behaviour. This must remain in the training!

What other main research topics and projects will you be working on at TU Braunschweig?

The overarching guiding theme with which I am starting and in which I have many years of research experience is the assessment and analysis of load-bearing structures in their interaction with surrounding media, such as wind or water.

This gives rise to many topics in the areas of wind and offshore engineering, but also very interesting research questions in the interaction of flexible protective structures with rockfall or debris flow, a landslide in the mountains. In other words, areas where the flexibility of structures is used to create targeted protective effects. All of this is on the agenda. I have already worked a lot with cable and membrane structures. These structures are characterised by extreme flexibility.

Furthermore, complementary experimental-numerical procedures are on the agenda, which on the one hand are necessary for securing results, i.e. for validation, in order to ensure the physical validity. For this, I need, for example, defined experiments or measurements on real structures. On the other hand, the linking of experiment and numerics is exciting with regard to the digital twin concept. That will definitely be a focus at the ISD.

Complex simulation processes are of course costly. With novel discretisation methods, such as isogeometric analysis (IGA for short), I would like to make the entire investigation process more efficient. I have been working on this for a long time, for example on the integration into the digital design chain. Besides IGA, other alternative discretisation techniques such as particle methods are also on the agenda. This allows us to pick the most useful methodology – or combinations of these and with the FEM – in order to address the real issues in the best possible way.

What made you decide to do research in this field?

I am an enthusiastic engineering scientist. The topics we have already talked about now I find enormously important and I feel the relevance of the research questions from different perspectives: that infrastructure is safe and ages safely, that bridges do not collapse, that we have to expect greater loads. The relevance and meaningfulness in these topics motivates me a lot and drives me forward.

Furthermore, “structural analysis” – and of course “dynamics” – is a highly interdisciplinary and versatile discipline. It is the link or interface discipline between the basic sciences: applied mechanics, numerical mathematics, the computer science disciplines, constructive engineering disciplines. That fascinates and excites me.

What excites you about your research?

I find it very motivating, for example, when the methods I research end up in practice and new research impulses are generated as a result. I also really appreciate working in large international and interdisciplinary teams. It’s great to tackle large projects in networks. What I also like very much is supporting young scientists in their professional and human development on their way to a doctorate. I am always very happy about every completed doctoral thesis! Another thing that fascinates me a lot is transferring research content into teaching, so that the teaching content is always state of the art. These are all points that make me enjoy going to work every day!

What constitutes good teaching to you?

I have now been working in university teaching for 20 years. Good teaching should sustainably establish the relevant competencies in students. To do this, I have to manage to arouse the students’ deep interest in the subject in the courses. The students should actively engage with the content and not just cram the material for the exam in the short term, so that they can implement a real and networked understanding of the content. And that is not so easy.

In terms of content, good teaching must cover a wide spectrum: the tools must be taught so that graduates can hold their own in professional practice, but we must also provide in-depth knowledge of the methodological and theoretical foundations. The students should be prepared for new kinds of questions in the future, be able to think their way into them and find innovative solutions.

What would you like to pass on to the students?

The students should be and remain curious and think outside the box. They should also train themselves in interdisciplinary thinking and acting, but still have their own roots. Internships and experience abroad are also important.

And of course, language skills are very important. If you want to be involved in larger projects, you can’t get around English. It is indispensable for many positions.

My advice is to consistently follow your own interests and to develop your skills even “sometimes with one course more than necessary”, because many things are much easier to learn during your studies than later parallel to a job.

An outlook on the future: What are your plans for the Institute?

As you have already seen, we are currently rebuilding the Institute. Here, too, many thanks to the faculty and university management. We are modernising and creating an attractive environment for a fruitful working atmosphere. Unfortunately, the construction is somewhat delayed and I hope that we will be ready in April/May 2022.

As far as the Institute’s work is concerned: I am a self-confessed team player. Because: The topics we are tackling now cannot be managed alone. I would like to further develop the focal points I mentioned as a team.

To this end, I would like to establish a simulation lab, also for networking with colleagues here at TU Braunschweig and outside, including a joint software platform in research and teaching. We all have so many overlaps here because we are working on the big questions of our time. In addition to the experimental facilities, we need scientists who work with the simulation environment. We need – in addition to the hardware – a powerful software environment, but of course we also need staff: laboratory managers who can master and maintain the software.