meccanica magazine56ENGCONSTRUCTADD - Resource-efficient steel CONSTRUCTion usingADDitive manufacturingThe interdisciplinary project EU-RFCS CONSTRUCTADD kicked-offon 8 September 2022 in Milan, aiming to place the Metal Additive Manufacturing(AM) in the mainstream of architecture and constructionby the year 2026.Politecnico di Milano will coordinate the project with partners RWTHAachen University, Università di Pisa, Prima Additive, BLM GROUP,FOMAS Group MIMETE, ArcelorMittal, Vallourec, IMDEA MaterialsInstitute, Cimolai Group, DNV. The project is funded by EuropeanResearch Executive Agency (REA) Research Fund for Coal and Steel#RFCS (2022-2026). Polimi joins the project with two departmentsnamely Department of Architecture, Built Environment and ConstructionEngineering and the Department of Mechanical Engineering.The researchers of DMEC will contribute by coordinating theactivities in process and material development using a novel constructionsteel grade for metal AM. In particular, the DMEC team coordinatedby Prof. Barbara Previtali and Prof. Ali Gökhan Demir willdevelop the processes towards the production of full scale demonstratorsusing metal AM with powder and wire feedstocks and laserwelding processes.CONSTRUCTADD aims to bring metal additive manufacturing in themainstream of steel construction community by developing rulesand procedures and regulate it for sustainable steel constructionapplications. Three Metal AM processes will be studied targetingarchitectural engineering and construction industry: Laser PowderBed Fusion (LPBF), Laser direct energy deposition (LDED), Wire archadditive manufacturing (WAAM).The global objective of CONSTRUCTADD is to contribute to Europe’ssteel industry to start making full use of Additive Manufacturing (AM)in the design, production and maintenance of complex and largesteel geometries to offer resource-efficient and reliable productswith reduced waste and energy consumption. To achieve the ambitionsof the project, specific objectives have been formulated:- Define specific AM material and process rules for large parts onquality, cost, processing, life cycle & recyclability, material safetyspecifications and aesthetics;- Selection of two powder and two wire feedstocks for productionas construction steel and quantify their processability with LaserPowder Bed Fusion (LPBF), hybrid Laser Directed Energy Deposition(LDED), and Laser Metal Wire Deposition (LMWD) in combinationwith laser welding, and an innovative approach to Wire Arc AM(WAAM) based on Cold Metal Transfer (CMT), quantify their recyclabilityand mechanical properties;- Design and produce demonstrator parts using the LPBF, LDED,WAAM, and apply welding technologies with process parametersdefined in the project;- Experimentally quantify the mechanical properties of 3D-printedsteel parts, and their structural integrity with the conventional steelelements;- Prepare the compliance route for construction parts produced byAM, introduce qualification, standardization, and certification templatescompatible with EN1090, and propose modifications to theexisting European building standards and regulations using the newexperimental outcomes;- Perform environmental and economic life-cycle analysis to establishcommercial and environmental benefits, and break-even pointsfor AM in steel industry;- Transfer research results to Eurocode-compatible design recommendations,guidelines and worked examples, to be used by the Europeanengineers, architects, and manufacturers;- Disseminate and exploit the project findings in the EU constructioncommunity to accelerate the acceptance of modern steel fabricationapproach studied in the project.By exploiting the power of additive manufacturing, CONSTRUCTADDwill accelerate the transition of the steel construction sector towarda sustainable production of structural systems. The project aims toshow that the sector can reduce the energy consumption of fabricatinga joint by approx. 30% and create less waste during fabrication,than existing manufacturing methods. AM will also unleash thesector from the constraints of traditional manufacturing and enablemass customization with increased production speed and quality, byplacing materials where needed and using advanced digital tools fordesign and production.CONSTRUCTADD plans to reduce the energy consumption by meansof:- Reducing the weight of critical complex parts while satisfying thefunctional design requirements (e.g. strength, stiffness) with thedeveloped Structural Design for AM (SDfAM) approach;- Customizing the joint geometries (shape and wall thickness) locallyto the internal stresses, moving the welds and the geometricaldiscontinuities away from the geometrically complex regions tobe able to orthogonally bolt or weld them to the conventional steelprofiles, decreasing the material and energy use hence the costs,and render the welds more accessible for periodic inspection andmaintenance.
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