World premiere of the first 3D-printed steel bridge

Materials World magazine
28 Nov 2018

The world’s first 3D-printed steel bridge previously featured in Materials World has now been completed, with a digital twin, and was unveiled at Dutch Design Week. Idha Valeur reports.

The 12.2x6.3m stainless steel bridge that will be located at Oudezijds Achterburgwal, at the crossing with the Stoofsteeg – located in the Red Light District of Amsterdam, Netherlands – has now also got a digital twin in the sensor network created by researchers at the Alan Turing Institute in collaboration with Imperial College London, University of Cambridge and Newcastle University, UK.

The digital twin’s – a virtual representation of the model – main objective is to help analyse the data produced by the sensor network, as well as doing extensive tests of the physical printed material. It will also use statistical methodology to reveal more about the actual material itself.

When people cross over the bridge, every footstep, every running foot and bike will generate digital data, that will provide insight about the structure, which is essential information for the researchers. Not only information about how the innovative new material and construction process behaves, but also about the potential for future infrastructure to act as living objects that do more for the cities they are placed in.

Dr Craig Buchanan, Lecturer in Construction at the Department of Civil and Environmental Engineering at Imperial College London, told Materials World, ‘At Imperial College London and Turing, we are doing material testing, cross-section testing, member testing, in-situ testing on the bridge, advanced computer modelling of the digital twin and developing a long-term sensor network.’

Buchanan said the network will allow for long-term monitoring of the bridge addressing queries such as how the bridge will change over time, peak loads the bridge experiences and when, as well as enabeling comparisons with current bridge designs, and whether you can predict the number of people on the bridge by monitoring accelerations. The monitor network was created by months of international collaborative effort, based on the predictions from advanced computer models.

‘This is important because it is the first time this material has been used in a public structure, and a unique opportunity to produce a structure that can gather a wealth of data that will influence future printed structures,’ Buchanan said.

The first set of data was gathered at the Dutch Design Week in October 2018. The data will bring insight into the traffic on the bridge, structural integrity and the surrounding neighbourhood and environment.

Liam Butler, from the University of Cambridge’s Centre for Smart Infrastructure and Construction, said, ‘Thousands of people are going to cross this bridge an hour so the City of Amsterdam is interested at looking at things like foot traffic, C02 emissions, noise and decibel levels.’

Buchanan explained that using stainless steel would minimise the need for additional steps to be made to ensure minimal corrosion. ‘The bridge is stainless steel, which means that it does not require additional corrosion protection. This 3D printing technique can use any metallic material that can be welded and produced as a wire,’ he said.

‘This project has demonstrated that metal 3D printing can be used at a scale suitable for construction. [This] opens up a wealth of opportunities, [such as] geometric freedom, engineered material properties, automated construction, among others,’ he concluded.

The team aims to have the bridge installed in Amsterdam in 2019, where the main focus will be to studying the changes of the bridge in real-time.