From TLS to Fe Analysis: Points Cloud Exploitation for Structural Behaviour Definition. The San Ciriaco’s Bell Tower

Abstract

<p><strong>Abstract.</strong> In the last few years, the evolution of acquisition techniques allowed to acquire reality-based models increasing accurate and rich of information. On the contrary, the ability to exploit the acquired data in the most efficient, economic (in terms of invested time), and impartial way (in terms of arbitrary choices of the operator) represents the most significant gap. Interoperability theme between points cloud and informative systems becomes relevant. Excellent results were achieved in 3D data exploitation in HBIM and GIS environments, as well as in VR and AR applications, whereas the structural analysis with the Finite Element Method (FEM) still lacks robust workflows based on point clouds. The present paper proposes a methodology allowing to transform the TLS point cloud obtained from the survey directly into a 3D FEM, in a semi-automatic way and, therefore, proposes a hybrid reverse engineering approach that aims to: (i) maximizing the correspondence between the model for structural analysis and the real object; (ii) minimizing the time and the operator’s decision. The strategy is validated on the belfry of the Metropolitan Cathedral-Basilica of Saint Cyriacus in Ancona, Central Italy. The reliability of the proposed model is assessed through a comparison between the model obtained from the Boolean modelling within a FEM software and the model obtained directly from points cloud processing. The comparison between the two numerical models highlights the enormous potential of the exposed method. The proposed case study shows how it is possible to develop high-quality 3D models, able to connect geometrical-historical survey with thematic analysis about structural behavior.</p>

Point Cloud Exploitation for Structural Modeling and Analysis: A Reliable Workflow

“…As mentioned, although this is a rather recent research area, there are several attempts pursuing this objective in literature. The study of (Korumaz et al, 2017)offers a classification of the different types of approach to the problem, in (Quattrini et al, 2019) we reviewed it and updated the framework. In this regard the present study offers a "direct use" methodology performed on the basis of the previous one and completely assessed.…”

“…An example of the "indirect use" approach is offered by (Fortunato et al, 2017). According to (Quattrini et al, 2019), the most performing approach in terms of accuracy is the "direct use" type, since it is less affected by the operator judgment. This same approach presents two modifications with growing refinement.…”

“…Retopology: it represents one of the most important upgrades in comparison with our previous works (Quattrini et al, 2019). Thanks to it, in fact, it was possible to drastically reduce the timing of model optimization.…”

An Integrated Geometric and Material Survey for the Conservation of Heritage Masonry Structures

“…For instance, Armesto et al [17] exploited photogrammetry to extract trusses for the evaluation of historic timber roof structures. The literature review shows that much of the efforts of the researchers are related to the automatic or semiautomatic creation of 3D geometric models to be employed for the creation of a 3D FE model [18][19][20][21][22]. Still, several issues emerge in the representation of heritage structures that always require several manual preprocessing operations.…”

“…Figure21. Pushover analysis in the longitudinal direction X for Model 2: damage state at failure for the walls W_X1 and W_X2.…”