Innovative Method for Automatic Shape Generation and 3D Printing of Reduced-Scale Models of Ultra-Thin Concrete Shells

Abstract

A research and development project has been conducted aiming to design and produce ultra-thin concrete shells. In this paper, the first part of the project is described, consisting of an innovative method for shape generation and the consequent production of reduced-scale models of the selected geometries. First, the shape generation is explained, consisting of a geometrically nonlinear analysis based on the Finite Element Method (FEM) to define the antifunicular of the shell's deadweight. Next, the scale model production is described, consisting of 3D printing, specifically developed to evaluate the aesthetics and visual impact, as well as to study the aerodynamic behaviour of the concrete shells in a wind tunnel. The goals and constraints of the method are identified and a step-by-step guidelines presented, aiming to be used as a reference in future studies. The printed geometry is validated by high-resolution assessment achieved by photogrammetry. The results are compared with the geometry computed through geometric nonlinear finite-element-based analysis, and no significant differences are recorded. The method is revealed to be an important tool for automatic shape generation and building scale models of shells. The latter enables the performing of wind tunnel tests to obtain pressure coefficients, essential for structural analysis of this type of structures.

A new method for corrosion assessment of reinforcing bars based on close‐range photogrammetry: Experimental validation

“…A photographic survey of the selected RBs specimens was performed after the accelerated corrosion tests, taking into account the recommended photogrammetric best practices . The photogrammetric procedure can be divided into the following main steps: Setup and specimen preparation; Image acquisition; Images preprocessing; Image referencing and 3D mesh generation; 3D model postprocessing. …”

“…[40][41][42][43] Several potentially new interesting applications of this technique to tackle problems in civil engineering have been presented. 44,45 These applications can take advantage of the commercial software available, provided that control parameters, which guarantee the quality of the data obtained, are evaluated, namely: ratio between distance-to-object and focal length; the sensor size; the number and location of the camera station; and the exposure of the camera (i.e., the relationship between aperture, shutter speed and ISO). 14 Thus, 3D models of an object can be computed using a multistation network configuration for image acquisition, follow-on higher precision photogrammetric projects and a suitable 3D model.…”

“…A photographic survey of the selected RBs specimens was performed after the accelerated corrosion tests, taking into account the recommended photogrammetric best practices. 38,45 The photogrammetric procedure can be divided into the following main steps:…”

3D Printing Technologies in Architectural Design and Construction: A Systematic Literature Review

“…There are three types of 3DP application for small-scale architectural models: (1) design exploration models [41,[44][45][46][47]49,50,[63][64][65][66], (2) design presentation models [43][44][45]48], and (3) test models [66]. The use of RP can be a part of design research or prototyping of small-scale models of large-scale 3DP constructions.…”

A Comprehensive Performance Evaluation of Different Mobile Manipulators Used as Displaceable 3D Printers of Building Elements for the Construction Industry

“…These surfaces result in high profile projects or iconic architecture designs. The main challenges of building element profiles are their complex geometries, size and repeatability of the task, which can affect the performance of the robotic systems [48,49]. Therefore the need of using mobile manipulators.…”