Project Details
Projekt
Methods and Tools for Design and Fabrication of shell-like and thin-walled Concrete Structures with Line Geometry. Short Title: Thin-walled Concrete Structures with Line Geometry.
Subject Area
Structural Engineering, Building Informatics and Construction Operation
Term
from 2011 to 2020
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 198226551
From the viewpoint of load bearing, skew ruled surfaces are favourable because they are basically of negative Gaussian curvature. Since ruled surfaces are generated through the movement of a straight line, they are also a good choice for concrete structures: the formwork can be produced from polystyrene foam with a hot wire cutter. Furthermore, at least in the direction of the rectilinear isocurves, straight reinforcement or even prestress is possible.But in construction industry only hyperboloids of one sheet (cooling towers) and hyperbolic paraboloids (hypars) have been used extensively. This selection does not take advantage of the wide range of possibilities for ruled surfaces at all. Moreover, the limitation to those shapes led to standardized components with a repetitive appearance (Silberkuhl-system). By contrast, today there is a demand for unconventional solutions to the question, how individual forms can be produced to reasonable conditions? Despite their importance, ruled surfaces are not yet properly implemented in common CAD software. However, the project »Line Geometry for Lightweight Structures« by the proposer Lordick, processed during the first phase of the SPP 1542, now delivers convenient mathematical foundations. One result is a form-finding tool (plug-in), which strictly operates in the class of ruled surfaces but nevertheless has the option to integrate load conditions.Now we have the task to make this new tool suitable for application and compare it to the known computation methods in the field of structural engineering. In an iterative process, the results of this comparison, along with other form-finding and optimization methods, shall be incorporated into the model of line geometry. The aim is to establish a workflow, which starts from an input-geometry, continues with static optimizations, and finally leads to the creation of the formwork, a workflow, which enables the designer to shape the structure according to the slogan »form follows force«. Our tool for ruled surfaces is a source for novel shapes and structures, for which we want to develop convenient concepts for structural design. These shell-like and thin-walled elements are predestined for textile-reinforced concrete, with or without prestress. We want to verify this by experiments, where we include typical boundary conditions and load cases for our new shell structures. Additionally, thin-walled structures under predominant compression shall be analysed numerically and experimentally with regard to stability failure. We want to evaluate the results of geometric and physical nonlinear finite element calculations in the light of the test results for the ultimate limit state.Within the project the applicants expect innovative building components not only for roofs, but also for beams, piers, and walls. This shall be proofed by a design workshop and a demonstrator.
DFG Programme
Priority Programmes
