Conference Paper

Building timber gridshells with air: Numerical simulations and technique challenges

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Abstract

Construction has always been a fascinating and challenging aspect of timber gridshells. So far, only three techniques have successfully been used for the erection of such structures: the so-called ‘lift-up’, ‘push-up’ and ‘ease-down’ (Quinn et al. 2015). Inflatable Membrane Technology is here proposed as a new solution and is tested by means of numerical simulations on a simple case study. As a matter of fact, IMT reduces the timber lath’s stress during erection and guarantees an optimal shape control. It also seems suitable to post-form more challenging gridshell geometries, but this aspect still deserves further investigations and experiments.

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... Airshell's design-and-construction workflow was based on D'Amico et al. [1], Liuti et al. [4], Pone et al. [6], so that design, manufacturing and construction could iteratively inform one another throughout the process (Figure 2). By embedding the pneumatic formwork at both the design and construction scales, form finding could be implemented and replicated with accuracy. ...
... By using the interactive physics/constraint solver Kangaroo2, the gridshell was modelled as a spring system made of two orthogonal mats of parallel polylines; these were given a bending stiffness adjusted according to an equivalent section and then connected at the nodes with hinge-like joints. In parallel, the pneumatic membrane was modelled from a closed mesh sphere as a spring system; form finding was adjusted to match the archetypical shape of Woodome1, but also considering the contribution given by the pneumatic formwork (Liuti et al. [4]). ...
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... When dealing with gridshells, the distinction between isotropic and orthotropic pattern is not straightforward and unanimously accepted in the scientific community and different criteria can be adopted. Some authors adopt a geometrical criterion and consider isotropic all the patterns with equilateral cells: according to this criterion, not only equilateral triangular, but also quad and hybrid meshes are isotropic [34]. Pietroni et al. [35] adopt a static criterion and define anisotropic the grid whose elements are aligned with the principal stresses of the underlying surface. ...
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... Alpermann [11] investigates an interesting low-tech method for informing the shape of post-formed arches by means of cable networks and membranes. Liuti in [9] and [10], on the experience of the Binishells erection method, proposes a numerical model, tested through a built prototype, that simulates the gridshell erection process though a pneumatic formwork. ...
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