Circularity Improvement in Retrofit of Constructions Using Lattice Arrangements Realized by Waam Enhanced by Leveraging Digital-Twins

Abstract

Circular Economy (CE) emerged as a new paradigm for sustainability in all key industries, including the construction sector which is the responsible for a large amount of gas emission, waste generation and material consumption. However, the application of CE in the construction industry is still hindered by the lack of standardized tools and by the fragmented nature of the sector, characterized by the predominance of Small and Medium Enterprises and still anchored to traditional manufacturing technologies. This explains why Automation and Additive Manufacturing (AM) are rapidly prevailing in almost all sectors with probably the only exception of the construction industry. The so-called Wire and Arc Additive Manufacturing (WAAM) process appears the most promising AM technology for steel constructions, for both new realizations (such as the first-world 3D printed bridge installed in Amsterdam) or repairing and upgrading of existing constructions.

Very recently, a novel deposition strategy, known as dot-by-dot WAAM, emerged. It consists in the successive deposition of single welding drops and appears to be particularly suitable to realize high structural efficient lattice structures. Their use could span from large structures covering stadiums to small energy dissipation devices. Nevertheless, before the full exploitation of dot-by-dot WAAM technology, knowledge advancements are necessary to fully comprehend the process-to-product interactions. The ambition of CIRCULAR WELD project is to improve the quality of dot-by-dot WAAM process and the reliability and precision of the 3D printed products by developing advanced digital models validated through process monitoring and experimental tests. These advancements enable the establishment of the Digital Twin (DT) model of the whole process-to-product workflow. The DT model will be developed and validate by employing an integrated circular approach consisting in several consecutive steps from requirements identification, models formulation and calibration up to their experimental validation.

The DT model will take into account the thermomechanical aspects of the printing process, the material geometrical and microstructural features, the mechanical parameters and structural response of the printed products. The process-to-product circularity and sustainability will be also assessed. The ambitious goal requires an interdisciplinary effort in the fields of Manufacturing & Technology, Structural Design & material characterization, Circularity & Sustainability, which are the main research areas involved in the project. The goals will be achieved by developing and testing a physical demonstrator representative of a novel lattice-based energy dissipation device for the seismic retrofitting of steel industrial facilities. The results of CIRCULAR WELD will bring Italy to the forefront of this emerging sector.

Team di ricerca UNIBO

Michele Palermo, Lidiana Arrè, Vittoria Laghi, Giada Gasparini, Valentina Girelli, Alessandro Ascari

Partner di progetto

Università di Firenze