Prototyping of thin shell wind tunnel models to facilitate experimental wind load analysis on curved canopy structures

Abstract

The topologies of membrane and shell structures are not covered by existing wind load Standards and wind tunnel testing should be used to obtain representative wind loads for these structures. However, accurate scale-models of these organically shaped and often open thin structures are complex, time-consuming and expensive to build. To stimulate experimental research on wind load distributions over these structures, this paper illustrates a prototyping methodology for double curved thin shell wind tunnel models with integrated pressure sensors. The production process is illustrated for a hyperbolic paraboloid roof structure. The obtained wind load distributions are validated with literature for a flat roof and canopy that is made according to the same methodology and for two hyperbolic paraboloid roofs. Results indicate that, compared to conventional wind tunnel models, these thin shell wind tunnel models yield more realistic wind pressure distributions over very thin canopy structures. Finally, Cp-distributions are shown for the hyperbolic paraboloid canopy with the high corner under attack. The production of glass-fibre reinforced composites in a CNC-milled mould is convenient and accurate and facilitates the production of wind tunnel models to be used for wind load measurements on organically shaped thin canopy structures.

Modeling and Wind Flow Analysis of an Eiffel (Open) Type Sub-Sonic Wind Tunnel

“…EG. [24]Jimmy Colliers' thesis shows how to prototype double curved thin shell wind tunnel structures with incorporated pressure sensors using a prototyping technique. A hyperbolic paraboloid roof structure's development mechanism is depicted.…”

Construction and dynamic identification of aeroelastic test models for flexible roofs

“…The scientific studies in the field of HPR can be grouped into four families: (1) studies discussing the structural behaviour of the HPR cable net [1,2,4,5]; (2) studies presenting the aerodynamics of HPR shape by [7] that gives parametric pressure coefficients maps for square and rectangular plan HPR with cables parallel to the roof sides and by [8] that discusses the statistics of pressure series on a square plan HPR and [9][10][11] that discusses the state of the art on HPR with cables at 45° with roof sides; (3) studies illustrating other multi-physics aspects, for example, the acoustic performances of HPR cable nets, as discussed by [12]; and finally, (4) studies investigating the wind-structure interaction in HPR roofs. Some examples are [13,14] discuss the aerodynamic damping and [15] discusses the structural dynamics in terms of natural modes of HPRs made of membrane only, [16] discusses the added mass and aerodynamic damping on a square HPR made of cables and membrane, [17] investigates the behaviour of large cable roofs in the turbulent wind in the wind tunnel using both rigid and aeroelastic models and finally, [18] that investigates the aeroelastic behaviour of an open-type one-way tensioned membrane through wind tunnel tests.…”

Discussion of Design Wind Loads on a Vaulted Free Roof

“…Such a thick model may deform the flow around the roof and the resultant wind pressure distributions on the roof significantly [1,4]. Colliers et al [12] established a hybrid rapid prototyping methodology for making double curved canopy structures. They successfully made thin models and measured the wind pressures on such models.…”