Wind-Structure Interactions of Tensile Surface Structures

Transcription

1 Wind-Structure Interactions of Tensile Surface Structures Training School COST Action TU1303 EUROMEM: From Uncertainties to Partial Safety factors Calibration Nantes, 28 September 01 October, 2015 Jimmy Colliers

2 Wind Structure Interactions of Tensile Surface Structures Reliability of wind design for tensile surface structures SLS and ULS Collapses

3 State of the Art document Literature Review Research Questions in Literature Complex influence of wind loading on the structural behaviour: organic shapes, low self-weight, flexibility The structural typology of membrane architecture is ignored by building regulations, even no information is provided about preliminary design or about wind loads. Detailed investigations on the complex aerodynamic behaviour of double curved structures are required. (Rizzo et al., 2011; Rizzo et al., 2012) The design wind force coefficients are influenced by the supporting system, the load conditions, the load paths, the roof stiffness, the shape and the deformations of membrane structures. (Nagai et al., 2010) (Takeda et al., 2014) The wind induced response of a membrane structure as a result of the wind-structure cannot be accounted by conventional analysis methods. Importance of aerodynamic damping and added mass should be further investigated. (Sun et al., 2008; Xuanyi et al., 2013)

4 State of the Art document Literature Review Limited representative research Hyperbolic paraboloid roofs (Otto, 1954; Rizzo et al., 2011; Rizzo et al., 2012) Conical or Horn shaped roofs (Burton and Gosling, 2003; Elnokaly et al., 2004; Nagai et al., 2012, 2011, 2010) Specific case studies (Baglin, 2002; Balz et al., 2004; Carradine, 1998; Michalski et al., 2004)

5 State of the Art document Literature Review Approaches in Wind Design Wind Loads (Cp-values) + Structural Finite Elements (FEA) Approximations based on Conventional Standards (Eurocode) Boundary Layer Wind Tunnel testing Computational Fluid dynamics Appropriate wind pressure data is essential to provide confidence in the analysis and design process

6 State of the Art document Literature Review Approximations based on Conventional Standards + Structural Finite Elements Pressure coefficient distributions of conventional building typologies No information about double curved surfaces Nature of textiles not considered Conventional Standards are insufficient for tensile surface structures, dynamics actions, flexible deformations NBN EN :2005 (BIN., 2005)

7 S(p)eedkits Clever Roof Design (Jan Roekens) Low-tech disaster shelter

8 S(p)eedkits Clever Roof Design (Jan Roekens) Low-tech disaster shelter Flat tarp of highly stretchable membrane (4m x 6m) Slightly anticlastic configuration

9 S(p)eedkits Clever Roof Wind Loading Static calculations (EASY) SLS and ULS EN : Duo-pitch canopy Simple overall force coefficients Extensive pressure coefficient distribution

10 S(p)eedkits Clever Roof Wind Loading Longitudinal wind down (symmetric loading) Unloaded equilibrium state Wind Loading: Simple force coefficients Wind loading: Extensive pressure coefficient distribution Longitudinal wind up (symmetric loading)

11 State of the Art document Literature Review Wind Tunnel Testing + Structural Finite Elements Direct pressure measurements by pressure scanner (rigid models) Reaction measurements by load cell (rigid or aeroelastic models) Deformation measurements by optical sensors (aeroelastic models) Wind Tunnel testing is complex and expensive a. Pressure scanner b. Load cell c. Optical sensors Rigid models Rigid or Aero-elastic models Aero-elastic models Three main wind analysis approaches on membrane structures (Nagai et al., 2011)

12 State of the Art document Literature Review Computational Fluid Dynamics + Computational Structural Dynamics Multi-field problem Partitioned approach with reference updating strategy (Sun et al., 2012; Kupzok, 2009; Wüchner, 2006) CFD module: Incompressible Reynonds Average Navier Stokes (RANS) + Large Eddy Simulations (LES) CSD module: geometrically nonlinear elastodynamics Coupling module: Mesh-based parallel Code Coupling Interface (MpCCI) Computational Fluid dynamics is sceptical approached

13 State of the Art document Literature Review Reliability of wind design for tensile surface structures How accurate is wind design while applying wind load estimations based on rough approximations referring to conventional building typologies from existing codes? To which extend are we designing safe structures by relying on the conservative static approach and ignoring the fluid-structure interaction due to flexibility of the structure? Accurate wind load analysis has to be investigated, development of Eurocode Section

14 ROUND ROBIN exercise III Collating wind data for the basic shapes of tensioned membrane structures Launched: January 2015 CEN/TC 250; COST Action TU1303; TensiNews 28 5 subscriptions (4 BLWT 1 CFD) Some relevant literature Closing deadline: September 2015 Analysis and dissemination of results

15 ROUND ROBIN exercise III Data Forms Form 1: Test Setup Form 2: Model specifications Form 3: Wind data measurements Wind tunnel test on a hypar canopy (Colliers, 2014)

16 FWO mandate PhD Thesis Wind-Structure Interactions of Tensile Surface Structures Behaviour under wind loading by numerically and experimentally studying pressure coefficients (Cp-values) WP1: Rigid flat and duo-pitch roof structures (EC1 part 1.4) WP2: Rigid hyperbolic paraboloid roof structures (shape dependency of Cp values) WP3: Flexible hyperbolic paraboloid roof structures (materials and pre-tension) WP4: Hyperbolic paraboloid membrane structure (integrated numerical simulation) WP5: Evaluate the accuracy of the current approach in design