Large-scale 3D printing and digital design could forever alter the shape of the built environment around us. Amsterdam’s robot printed steel bridge, set to be installed in the city’s Red Light District, is a 12-metre long digital design masterpiece with curved, raw steel balustrades that belie its high-tech origins.
The award-winning design, developed by Dutch technology start-up MX3D together with designers Joris Laarman Lab and a host of collaborators, offers a glimpse into how computational design together with state-of-the-art robotic welding technology could shape our cities in the future.
Now fully 3D printed in stainless steel, the bridge is the culmination of a long-running dream that welds traditional steelwork and advanced digital modelling into an inspired, structurally sound piece of public urban infrastructure. Computational design and 3D printing come together to streamline both the design and production process, allowing designers to explore greater form freedom and shrink delivery timelines.
With Arup involved as lead structural engineer, MX3D created intelligent software that transforms welding machines into 3-D printing robots to produce a fully functional steel bridge. Advanced parametric design modelling – a tool for designers exploring new shapes using code - enabled Arup engineers to significantly fast-track the initial design process. The software can produce several iterations in quick succession until arriving at an optimal shape that offers the best solution against a set of benchmarks.
Departing from a monolithic, U-shape bridge design, the design team ran extensive iterations to progress swiftly through several stages of design until delivering the final, more organic, S-shaped bridge - marrying structural integrity and functionality without compromising on aesthetic relevance.
Designing by experimenting: digitally-driven design process tests new boundaries
Transcending its public function as a footbridge across the Oudezijds Achterburgwal canal, MX3D serves as a proof point of how digital design tools and 3D printing may forever alter the built environment. As a design object for public use, Joris Laarman wanted MX3D to be a revolutionary piece of art, fully exploring the rational design freedom allowed by 3D printing for large-scale infrastructure.
Parametric design modelling was a perfect fit for this boundary-pushing design process. The team worked with Grasshopper and Karamba, a tool for designers exploring new shapes using generative algorithms (graphical algorithm software) for 3D modelling tool Rhino, to refine the design. The programme works by producing successive design iterations under a given set of parameters, moving from an initial test form towards the optimal or final shape. Additional software can assign accurate material properties to the model, enabling extensive testing including for instance load path analysis, even before the final bridge is physically built. The team ran digital simulations of the bridge, removing excess material by mixing structural calculations with geometric manipulation, teaching the algorithm to recognise which parts of the bridge are less crucial
Designing beyond the codified materials was made possible thanks to repeated testing: Lab material test results, structural element tests results and full-scale final test results would inform engineers working out the design. The testing sequence feed into the structural assessment and allowed the engineers to check the safety and serviceability of the bridge.
3D printing comes of age: printing large-scale urban objects
After arriving at a final design, the team moved into the production phase. Understanding the performance of this material was one of the first steps of the process: the material and mechanical properties of this self-supporting 3D printing steel differ from that of regular steel. To address this, the team ran several tests including load viability to ensure that the structural behaviour of the bridge complies with code safety requirements and confirm the performance of this new 3D printing steel.
3D printing, also known as additive manufacturing, is a novel method of manufacturing parts directly from a digital model by building layer after layer of a material. This new, high-precision technique provides opportunities and architectural freedom to designers and engineers alike, while potentially reducing the amount of materials used and wasted. Printing began in March 2017 and the completed bridge was put on display at Dutch Design Week by October 2018.
Digital Twin: data sensors to track performance
The bridge will be equipped with a sensor network, allowing the partners to gather data which will be used to build a digital twin to monitor the health of the bridge. The digital twin will track performance under different environmental conditions and under changing dynamic loads, including tracking pedestrian use, checking corrosion or studying deflection and support forces, all of which will enable the further development of a data-centric design language.
Collaborative partnership: key to innovation in the built environment
To bring the project to life, MX3D set up an innovative working collaboration with a large group of partners marrying expertise across disciplines, including software, hardware, construction and welding. These include Autodesk, ArcelorMittal, Arup, Force Technology, Imperial College London, Air Liquide, ABB Robotics, Heijmans, Lenovo and Lloyds Register Foundation.
Among the public partners are TU Delft, AMS Institute (Amsterdam Institute for Advanced Metropolitan Studies) and the Municipality of Amsterdam. On the sponsoring side are STV, Oerlikon, FARO and Plymovent, while the Visitor Centre is supported by the VSB Fund.