Cloud-to-BIM-to-FEM: Structural simulation with accurate historic BIM from laser scans

Abstract

The complexity of historic constructions, with irregular geometry, inhomogeneous materials, variable morphology, alterations and damages, poses numerous challenges in the digital modeling and simulation of structural performances under different types of actions. Although recent developments in Building Information Modeling have introduced advanced simulation capabilities, the numerical characterization of historic buildings is still a challenging task for the lack of reliable procedures for structural simulation.This paper presents an innovative two-step methodology (Cloud-to-BIM-to-FEM) able to convert a historic BIM into a finite element model for structural simulation. The generation of the BIM (Cloud-to-BIM) is carried out with an accurate survey that integrates geometrical aspects, diagnostic analysis based on destructive and non-destructive inspections, material information, element interconnections, and architectural and structural considerations. The BIM is then turned into a finite element model (BIM-to-FEM) with a geometric rationalization which preserves irregularities and anomalies, such as verticality deviation and variable thickness. After setting material properties, loads, and boundary conditions, the structural simulation is run with a detailed model that respects the uniqueness and authenticity of the historic building, without the typical excessive geometric simplifications of the shape.A real case study is illustrated and discussed to prove that a rigorous Cloud-to-BIM-to-FEM workflow allows the generation of an accurate historic BIM from a set of laser scanning point clouds. Structural simulation was carried out with a 3D mesh derived from the BIM in order to take into consideration the geometrical irregularity of a castle. Here, the advantages and disadvantages of the proposed approach are illustrated and discussed.