Visual programming for the structural assessment of historic masonry structures

The objective of this work is to formulate a new methodology the assessment of masonry structures that is using a fully digital procedure to automatically build up a reliable structural model, limiting expensive destructive tests. Data arising from laser scanning surveys and digital photogrammetry techniques are employed to generate a detailed 3D model that can be automatically imported in a Finite Element (FE) software environment. This is used to perform a non-linear static analysis aiming at investigating on possible collapse modes of the structure. As the focus is not on the actual structural capacity of the structure, such results are not strongly dependent on material parameters employed, which are set based on engineering judgement only. This preliminary structural analysis is employed to generate a possible configuration of failure surfaces through the Control Surface Method (CSM), which is here proposed for the first time. These are associated to the 3D models and implemented into a visual coding which embeds an upper bound limit analysis of the problem assuming a no-tension material hypothesis. Based on such failure surfaces, Genetic Algorithms are used to generate other possible collapse mechanism and search for the actual failure mode corresponding to the minimum value of the loads multiplier. The work-flow is all integrated into a computational tool implemented in the visual programming environment offered by Grasshopper and Rhino3D. The procedure is validated by the analysis of one benchmark case, whose results are presented and discussed.