WS1 : ASYMPTOTIC GRIDSHELLS
Design for construction, using Bowerbird and Kiwi!3D
Instructors: Eike Schling, Jonas Schikore, Thomas Oberbichler
The Workshop will explore the geometry, design, structural analysis and fabrication workflow for asymptotic gridshells, combining two novel Grasshopper Plugins: Bowerbird and Kiwi!3D. Asymptotic Structures have shown high potential for the fabrication, assembly and load-bearing capacity of elastic gridshells. Asymptotic structures allow for a simple 2D fabrication from exclusively straight lamellas.
The lamellas can be assembled flat and deformed into their curved design shape, following a compliant mechanism, without the need for formwork. Throughout this process, the slender profiles are only bent around their weak axis, while their strong axis remains straight, offering high stiffness against normal loads.
The digital workflow of designing asymptotic nets, modelling and analysing their structural geometry and producing fabrication files has been automated through the use of Bowerbird - introducing direct curves on surfaces with full control of all curvature values - and Kiwi!3D - allowing the use of NURBS for form-finding
and FE-analysis of large deformations including helix torsion. The workshop will utilize this new efficiency to explore the world of asymptotic nets and their structural performance. A physical output, including the construction of a 1:1 prototype.
The workshop is combining fundamental theories of differential geometry, mechanics and design, thus touching upon all relevant fields of the AAG. It was conceived for all creative professions, interested in an applied workflow, from Architects and Engineers to Computer Scientists and Mathematicians, with previous experience in parametric modelling.
Bowerbird is a plugin for Grasshopper which provides tools for the fabrication of free form geometries. It allows the analysis of the relevant curvature parameters, namely normal curvature, geodesic curvature and geodesic torsion. Furthermore, it is possible to search for paths with specific curvature properties on free
Kiwi!3D is a tool for meshfree modelling and simulation of complex structural systems with Isogeometric Analysis (IGA). IGA is a new and innovative computational approach within Finite Element Analysis, which allows performing simulations of structural behaviour directly on the NURBS parametrization of CAD geometry objects. Kiwi3d integrates modules for geometrical linear and nonlinear analysis as well as cutting edge form-finding algorithms and building process routines.
Hong Kong University