There are concrete 3D printed bridges, and bridges 3D printed out of modified plastic. Now, we’re one step closer to seeing a first-of-its-kind bridge built by robots and 3D printed using stainless steel. Netherlands-based startup MX3D, which develops robotic additive manufacturing technology and created the Wire and Arc Additive Manufacturing (WAAM) method, got started on the ambitious project back in 2015, together with project partners Autodesk, Heijmans, and Joris Laarman Lab.
The goal was always to build the 3D printed steel pedestrian bridge over one of the historic canals in Amsterdam, but MX3D had some setbacks with the first bridge design, as it would have placed too much stress on the canal walls. But now that the design has been updated to a more traditional one, with complex accents like bends and turns that would not have been possible without 3D printing technology, the project is back on track.
About one-third of the bridge has been 3D printed in the MX3D lab, with a planned installation date in late 2018 over the Oudezijds Achterburgwal canal in Amsterdam. The completed bridge will be open to cyclists and pedestrians.
But that’s not all – according to Imperial College London, the first 3D printed steel bridge will also be the largest 3D printed metal structure in the world, and something of a “living laboratory” as well. A multi-disciplinary research team, led by MX3D and The Alan Turing Institute, will be measuring, monitoring, and analyzing the performance of the 12-meter-long bridge.
A team of computer scientists, mathematicians, statisticians, and structural engineers from The Alan Turing Institute-Lloyd’s Register Foundation data-centric engineering program, Imperial College London, and the Centre for Smart Infrastructure and Construction at Cambridge are designing a massive sensor network that will be installed on the bridge. These sensors will measure environmental factors like temperature and air quality, so engineers can monitor how the bridge’s health changes over time; data will also be collected on several structural measurements, like displacement, strain, and vibration.
“The 3D printed bridge being installed by the MX3D team next year will be a world first in engineering. This data-centric, multidisciplinary approach to capturing the bridge's data will also mark a step-change in the way bridges are designed, constructed, and managed, generating valuable insights for the next generation of bridges and other major public structures,” said Professor Mark Girolami, Chair in Statistics in the Department of Mathematics at Imperial College London and the leader of the program.
“It is a powerful embodiment of what data-centric engineering can deliver as a discipline, and I look forward to seeing the bridge in action from summer next year.”
All of the data that the sensors collect will be added into a living computer model, or digital twin, of the bridge, which will accurately imitate the 3D printed bridge in real time as the data comes in. The Steel Structures Group in the Department of Civil and Environmental Engineering at Imperial College developed the model, and will test the behavior and performance of the real bridge against it, which will allow it to be modified for any safety and security issues that may occur.
“3D printing presents tremendous opportunities to the construction industry, enabling far greater freedom in terms of material properties and structural geometries, but this freedom also brings a range of challenges and will require a new way of thinking for structural engineers,” said Professor Leroy Gardner, who is leading the Steel Structures Group.
At the moment, the group is testing samples of the 3D printed steel in an attempt to anticipate the bridge’s behavior under load so its design can be updated if necessary.