The NOSA-ITACA code for modelling and assessing the structural behaviour of ancient constructions

Recent studies have led to the implementation of the finite element code NOSA, in which masonry is described as a nonlinear elastic material with zero tensile strength and bounded compressive strength. The code has been successfully applied to a number of studies on important historic buildings, such as the Medici Arsenal and the church of San Pietro in Vinculis in Pisa, the bell tower of Buti, the church of Santa Maria Maddalena in Morano Calabro and the Rognosa tower in San Gimignano. With the aim of improving the performance of the NOSA code and equipping it with an interactive graphic tool for pre- and post-processing, the project "Tools for the modelling and assessment of the structural behaviour of ancient constructions" has been conducted by the laboratory of Mechanics of Materials and Structures of ISTI-CNR and a research team from the Department of Civil and Environmental Engineering of the University of Florence. The project, funded by the Region of Tuscany (2011-2013), has led to the development of the NOSA-ITACA code, resulting from integration of the NOSA code and the open source graphic platform SALOME. The NOSA-ITACA code has been used to study the church of San Francesco in Lucca, Italy. The church has been studied under two different conditions: in its actual state and in the presence of reinforcement structures. This case study highlights the important role of mathematical models and numerical tools in assessing the mechanical behaviour of historical masonry buildings in the presence of earthquakes, as well as in planning strengthening operations on such structures.