Struttura e architettura nella scuola italiana di ingegneria. il “ridisegno ricostruttivo” e la stampa 3d come strumenti di conoscenza

How did the architects and their many collaborations with the engineers contribute to the history of Italian structural engineering in the second half of the 20th century? How did they participate in defining the identity of the Italian School of Engineering? Reconstructing the history of Italian structural engineering, it turns out that there is a "story within the history". We talk about the story of two generations of engineers and architects working together, while international fame of Italian School of engineering spread worldwide and the great "made in Italy" structures become an icon in the world.This contribution faces the subject through the story of some material investigations conducted on a selection of significant "structural architectures", carried out between 1945 and 1980, but especially through the evolution of the pioneering tools of investigation introduced by Sergio Poretti for the study of 20th century architecture: the "reconstructive redrawing" - which from the axonometric cross-section, made with the 2D Cad, developed it selfs in the 3D virtual model and in 3D printed models, embodies a fundamental tool of knowledge for the analysis of the relationship between form and structure. The contribution is part of the SIXXI project (ERC Advanced Grant, PI Sergio Poretti, Tullia Iori - www.sixxi.eu), within the SIXXI3DLab.