Geometrical processing of real data for Finite Element Analysis of historical fortified structures

The use of Finite Elements Analysis (FEA) for ancient structures and artefacts has recently shown great potentialities. The typical workflow of such analysis involves the use of CAD 3D models made by mathematical surfaces, representing the ideal shape of the object to be simulated. For Cultural Heritage objects, altered by the time passed since their original creation, the representation with a schematic CAD model may introduce an excessive level of approximation leading to wrong simulation results. The focus of this paper is to present a new method, based on a wise use of retopology procedures, aiming at generating the most accurate 3D representation of a real artefact/scenario from 3D models derived from reality-based techniques, maintaining as much as possible the accuracy of the high-resolution polygonal models in the solid ones while minimizing the number of nodes to a level compliant with FEA. This allows to obtain FEA results that are closer to the actual mechanical behaviour of the analysed heritage asset. Such methodology is here described and applied to the structural analysis of the Tower of the Marenyet in Valencia (Spain).