Insight

Chair of fastening technology, TU Dortmund University

Panos Spyridis recently became the chair of fastening technology – a new position for the faculty of architecture and civil engineering at TU Dortmund University. Editor Will Lowry visited the Dortmund campus to speak to Panos about his new position and the role fastening technology plays within the university’s curriculum.

Whilst he was still studying at university, Panos had the opportunity to visit the University of Life Sciences and Natural Resources in Vienna, Austria, where there was already an ongoing research group on fastening technology – working in close collaboration with the industry.

“I ended up doing my doctoral work on this subject and worked with brilliant people, including experts from Hilti and fischer,” explains Panos. “It was interesting to see how two big competitors worked very tightly together, in a very good collaborative environment, to promote the know-how in the area of construction fixings and fastenings in concrete.”

After this Panos worked as a consultant and practicing engineer in London on projects including Crossrail and the London Tube upgrades, as a structural tunnelling engineer. “It was already my idea when I finished my research work to go out and get a good understanding of industry practice and the business environment, then draw this technical and industry/commercial knowledge back to a university.”

That university was TU Dortmund after it decided to expand its coverage of fastening engineering. “I started at the university at the beginning of 2018 and I recently became the newly introduced chair of fastening technology,” mentions Panos. “The term fastening technology is actually a direct translation from the German term ‘befestigungstechnik’. However, the role expands to constructional engineering and involves fastening and assembly engineering principles.”

Whilst there has been a legacy of expertise in fastening technology at TU Dortmund, it has now become a topic of its own, which shows the intention of the university to solidify its expertise in fastening engineering. “We belong to the faculty of civil engineering and architecture, which is another special aspect of TU Dortmund. Civil engineers and architects sit together in many of the courses and do projects together, which helps them understand neighbouring but differing disciplines.”

As part of both the Bachelor and Master courses for civil engineering and architecture there are different modules that focus on structural engineering, architecture and city planning, as well as construction management, including building services. “Fastening technology is connected to all of these different modules,” points out Panos. “Our main focus is structural engineering, but we do a lot of work in regards to worker safety, construction logistics and Building Information Modelling (BIM).”

Regarding fastening technology, Panos highlights that there are essentially two courses. “One is a basic course, where students understand the different technologies, the different applications, and the installation principles, which is a very important part of our field. We are talking about a lot of manual work, so there are a lot of risks of defects in installation. We try and train the students to manage a project where fastenings are included, so they can understand what they need when they have to install some fastenings. This covers safety critical fastenings and non-structural fastening for all fields of application.”

Panos continues: “There is also an advanced course, which is typically taught to structural engineering Masters students. The focus is on teaching the actual design for fastening into concrete and masonry, with special focus on EN 1992-4 2018 Eurocode 2 – part 4. This is the new design standard, and it is an obligation for structural engineers for when they deliver a design project to have all fastenings designed with this Eurocode.”

The aim is for students of both courses to have more or less all the available knowledge related to fastenings – from structural engineering details to material science, to what is going on in practice, as well as how to use design software. Plus, what the European technical approvals dictate, and how they are developed.

“The students will be able to understand how a fastening is manufactured, designed and installed – the whole fastener process. This shows the importance of fasteners is growing within the educational sector and I am actually visiting a lot of other universities abroad to give some lecturers on fastenings.”

With risk, reliability and safety vital parts of a fastening’s design and performance, Panos believes there is movement within the civil engineering market for the development of risk/performance-based design. “The way we design structures today is very much based on empirical observations with a lot of added safety. This is sometimes expensive and also not realistic. With performance-based design you are looking at the performance for the everyday use and the performance for extreme situations.”

“We also have the aspect of life cycle, in what we do. Historically, we have mostly focused on how the structure will behave as soon as it is commissioned. However, now the aspect of sustainability and long-term behaviour is coming into play. We are talking about designing under a lot of uncertainty. The operation is something we can possibly predict, but it still has a lot of fluctuations. The extreme events is something we have difficulty to predict, but we somehow consider it.”

“Then the long-term performance of materials and fastenings, and the changing actions of loads on anchors over time, is something we also have difficulty to predict. If we design based on this type of focused performance requirements, we come up with more realistic and economical, as well as safer solutions. In the end it all comes down to risk, what is the risk we can take. If there is a big event – earthquake, fire, flood – how will the structure handle it?”

Another area the fastening department is looking at is the digitalisation of design and construction. “Currently companies have CE Marking for their products, but they are finding more and more they need a digital twin, which includes all the relevant details. This means the information of the product does not just stay on the paper, but it can be communicated in a standard manner via digital planning or a design document.”

“At the moment we are looking at what is needed and how we can combine it with the other software we have – what is the best way to use it, how can we improve it? We are also talking to end users about what they need regarding the CE Marking information and ensuring it is available digitally.”

Other areas the department is looking at includes the use of fastenings with new materials, for instance carbon fibre reinforced materials; applications of retrofitting; as well as development of anchoring products.

“We are also currently collaborating with some fastening companies using applied and fundamental research and also supervise the training of labour staff for the installation of fastenings,” mentions Panos. “We are also open to working with further fastener companies, who are looking to develop new products or test the capabilities of their existing products.”

Regarding trends within the construction section, Panos believes the shift from on-site construction to construction off-site will continue to develop. “Fixings are strongly related to manual work and I am certain there will be a large shift from on-site to off-site construction. This type of work leads to the opportunity for the integration of fastening installation to a robotic or automated procedure. However, this creates a whole host of other questions regarding fastenings.”

“Traditionally, fixings for the construction sector are conceptualised for manual installation. If there is a big shift towards off-site construction and installation via robotics or automation, does this mean we need to rethink how the fastening is designed? Typically, fixings are made to be torqued by a wrench, which is operated by a human that can pull it to 20kg – 30kg. However, if you swap this with a robot or automated machine, the installation will be done a lot quicker and with more power and precision, which creates a lot of opportunities and challenges. So, on one side we have the engineering community that supplies new concepts in the design and construction and on the other hand we have the acceleration of off-site construction where fastenings could play an important role.”

“Either way, fastenings are some of the most highly engineered construction products on building sites. They are manufactured with precision and with tight manufacturing specifications, which means there are a lot of opportunities for the future.”