3D-printed steel bridge at University of Twente

World’s first 3D-printed steel bridge at the University of Twente

A world’s first and an ambitious project to say the least: 3D printing a steel bridge. As of September this year, the first of its kind stands at the University of Twente. Here, it is being subjected to all kinds of performance tests. “Although quite the eye catcher, it is not only the great design that is so special about it”, tells Rolands Kromanis of the Faculty of Engineering Technology and Tenure Tracker at the 4TU Centre for Resilience Engineering.

Innovative sensing technologies
The futuristic looking construction was first revealed at the Dutch Design Week in 2018. By using ground-breaking robot technology, the 3D-printed segments were produced piece by piece. However, the structure itself is only part of what makes it so special. With a wide array of sensing technologies, it can measure both the condition of the bridge itself and its environment. This is also where Rolands Kromanis comes in, as he is involved in Structural Health Monitoring (SHM) and, together with Farid Vahdatikhaki, responsible for the sensor network: “As with all structures, this bridge is bound to experience certain stresses during its lifetime. Normally, you would determine the state of this bridge by inspecting it subjectively. You look at a crack and have to determine whether this could pose a problem. By using sensor data, we can detect objectively and continuously if there’s potential damage. If this is the case, we can locate it and determine what it means for the bridge; how much it would cost to repair and how it affects the lifespan.”

Quick assessment of structures
Using such sensor technology allows organizations to quickly and accurately determine the condition of a structure. Making the link to the resilience of infrastructure, this is also useful in the case of large impact incidents. After these types of events, it is vital to assess the damage of structures as fast as possible. These technologies could provide this information without having to rely on in-situ observations. In turn, this accelerates the damage assessment stage and consequently the rehabilitation of damaged structures.

Observing the environment
Apart from assessing the health of structures, sensors can also be used for other purposes. One example is in the tourism sector: “Using sensor data, we know how many people use the bridge and when it is most frequently used. Furthermore, these sensors allow us to identify suspicious behaviour. For example if someone has been standing at the same spot for half an hour. The large advantage of using sensing technologies is also the privacy aspect, as sensor data is often much more anonymous. Overall, projects like these are vital for making the system as intelligent as possible.”

For now, the bridge will remain on campus, where it will undergo a lot of testing. “In the next couple of months, we and a number of other organizations involved in the project will continue testing the bridge. Then it will be moved to Amsterdam, where it will be installed in one of the most touristic districts.”