1. FEASIBILITY STUDY OF HYBRID WOOD STEEL STRUCTURES
By:Yalda Khorasani
08/11/2010
Feasibility Study of Hybrid Wood Steel Structures by Yalda Khorasani

2. Feasibility Study of Hybrid Steel Timber Structures
21/04/2017
Outline
Properties of Steel, Wood and Concrete
Types of Hybridization
Case Studies of Hybrid Structures
Software Packages Investigation
Hybrid Steel Frame And Wood Shear Wall Model
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Feasibility Study of Hybrid Steel Timber Structures

3. Properties of Steel, Wood and Concrete
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Properties of Steel, Wood and Concrete
Steel :
Good Tension Capacity
Ductile
Linear Stress Strain Relation
Isotropic
Wood:
Good Compression Capacity
Low tensile Capacity
Stiff
Non-Linear Stress Strain Relation
Orthotropic
High Strength/Density Ratio
Hygroscopic Material
Concrete
Non Linear Stress Strain
Brittle Fracture
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Feasibility Study of Hybrid Steel Timber Structures

4. Fig 1. Stress Strain Diagram of Steel-Tension
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Feasibility Study of Hybrid Steel Timber Structures

5. Fig. 2. Stress Strain Diagram of Wood-Compression Parallel to Grain
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Feasibility Study of Hybrid Steel Timber Structures

6. Feasibility Study of Hybrid Steel Timber Structures
Fig. 3. Stress Strain Diagram of Wood –Compression Perpendicular to Grain
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Feasibility Study of Hybrid Steel Timber Structures

7. Fig. 3. Stress Strain Diagram of Concrete - Compression
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Feasibility Study of Hybrid Steel Timber Structures

8. Advantages of Hybrid Wood Steel Structure
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Advantages of Hybrid Wood Steel Structure
Increase Load Bearing Capacity
Increased Seismic Performance
Cost Benefits
Increased Durability
Higher Fire Resistance
Allows Pre-Fabrication
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Feasibility Study of Hybrid Steel Timber Structures

9. Types of Hybrid Structure
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Types of Hybrid Structure
Component Level Hybridization
Hybrid Bridge Decks and Slabs
Hybrid Beams/Columns/Braces
Hybrid Joints
Structural Level Hybridization
Hybrid Roof Trusses
Vertical Mixed System
Hybrid Steel Moment Frame and Wood Floor Diaphragm
Hybrid Frames
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Feasibility Study of Hybrid Steel Timber Structures

10. Structural Level Hybridization
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Structural Level Hybridization
Roof trusses: combining steel members in tension with wood members in compression
Example: in Southridge School in Surry
Fig. 4 Southridge School Roof Structure
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Feasibility Study of Hybrid Steel Timber Structures

11. Structural Level Hybridization
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Structural Level Hybridization
Hybrid Frame:steel as column and timber as beam
Sainsbury’s Dartmouth warehouse in Devon, England
Fig 5. Steel Column-Glulam Roof
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Feasibility Study of Hybrid Steel Timber Structures

12. Structural Level Hybridization
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Structural Level Hybridization
Building structure consisting of steel moment resisting frame and composite timber long span floor joist and plywood flooring
Advantages:
Cost benefits
Better Seismic Performance
Construction Benefits
Fig 6. Steel Moment Frame and Wood Diaphragm floor
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Feasibility Study of Hybrid Steel Timber Structures

13. Structural Level Hybridization
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Structural Level Hybridization
Vertical Mixed System: structural system comprised of concrete/steel first floor and wood upper storeys
Advantages:
Satisfy the Code requirement for fire resistance
Increased load bearing capacity
Fig 7. Concrete first floor, timber structure upper 8 storey
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Feasibility Study of Hybrid Steel Timber Structures

14. Component Level Hybridization
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Component Level Hybridization
Flitch Beam: A steel plate sandwiched between two wood joists and bolted together
Advantages: Supports heavier loads over a longer span
Fig 8. Typical flitch beam
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Feasibility Study of Hybrid Steel Timber Structures

15. Component Level Hybridization-Hybrid Beams
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Component Level Hybridization-Hybrid Beams
Wood member reinforced with steel plates :wood member reinforced by steel plates on top and bottom or reinforced with steel plate in between.
Advantages :
increased in fire resistance
improved buckling capacity
increased in bending strength
Fig. 9 Hybrid wood steel member
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Feasibility Study of Hybrid Steel Timber Structures

16. Component Level Hybridization-Hybrid Beams
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Component Level Hybridization-Hybrid Beams
Wooden members with built-in steel materials: H-shape steel member, square steel bar or steel plates
Advantages :
increased in fire resistance
improved buckling capacity
increased in bending strength
Fig. 10 Hybrid wood steel member
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Feasibility Study of Hybrid Steel Timber Structures

17. Component Level Hybridization
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Component Level Hybridization
Hybrid Bridge Deck: similar to composite construction where two different materials are bound together so that they act together as a single unit from a structural point of view.
longitudinally laminated prestressed wood decking
steel girders
shear bulkheads: shear studs in concrete filled holes
Fig. 11 Hybrid bridge deck
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Feasibility Study of Hybrid Steel Timber Structures

18. Component Level Hybridization
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Component Level Hybridization
Hybrid DuctileTimber Joint: Similar to post-tensioned precast concrete building systems.
Can be used for beam-column, wall foundation or column-foundation
Fig 12. Hybrid Joint
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Feasibility Study of Hybrid Steel Timber Structures

19. Hybrid Steel Concrete Structure
Type=Component level
Composite reinforced concrete and steel moment frame structures
Advantages=
Cost saving
Longer span
Minimize field labour
Joint Detail=
Through beam
Through column
Fig. 13. Joint Detail
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Feasibility Study of Hybrid Steel Timber Structures

20. Hybrid Steel-Timber Structure
Type = Component Level
Six storey building uses post-tensioned steel tendons in timber frames and structural walls.
Advantages=
Increased seismic performance
Rapid erection
Economical connections between the large timber elements
Fig. 14. Post tensioned members
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Feasibility Study of Hybrid Steel Timber Structures

21. Hybrid Concrete- Steel-Timber Structure
Type = Component + Structural Level
Reinforced concrete structure first storey and the second to fifth stories have a timber-based hybrid structure with built-in steel materials
Advantages=
Satisfy Code requirement for fire safety
Increased buckling capacity
Fig. 15. Hybrid members
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Feasibility Study of Hybrid Steel Timber Structures

22. Feasibility Study of Hybrid Steel Timber Structures
ANSYS
Types of analysis: Static, modal, harmonic, transient dynamic, spectrum, buckling, explicit dynamic analysis
Capable of modelling:
Linear and non-linear material
Isotropic and Orthotropic material
Composit and layered material
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Feasibility Study of Hybrid Steel Timber Structures

23. Table 1. Ansys material library
Linear Material
Non-Linear Material
Specialized Material
Elastic Isotripic
Elastic
Inelastic
ViscoElastic
Gasket
Elastic Anisotropic
Hyperelastic
Rate Independant
Curve Fitting
Joint Elastic
Elastic Orthotropic
Multilinear Elastic
Rate Dependant
Prony
Creep
Non Metal Plasticity
Maxwell
Composites
Cast iron
Table 1. Ansys material library
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Feasibility Study of Hybrid Steel Timber Structures

24. Feasibility Study of Hybrid Steel Timber Structures
SeismoStruct
Types of analysis: Dynamic and static time-history, conventional and adaptive pushover, incremental dynamic analysis, eigenvalue, and non-variable static loading
Capable of modelling: Concrete and steel but not wood
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Feasibility Study of Hybrid Steel Timber Structures

25. Table 2. SeismoStruct material model
Steel
Reinforced Concrete
Composites
Bilinear steel model
Trilinear concrete model
Nonlinear FRP-confined concrete model
Menegotto-Pinto steel model
Nonlinear constant confinement concrete model
Superelastic shape-memory alloys model
Monti-Nuti steel model
Nonlinear constant confinement concrete model with tension softening
Trilinear FRP model
Nonlinear variable confinement concrete model
Elastic material model
Nonlinear constant confinement model for high-strength concrete
Table 2. SeismoStruct material model
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Feasibility Study of Hybrid Steel Timber Structures

26. Feasibility Study of Hybrid Steel Timber Structures
SAPWood
Types of analysis: Traditional nonlinear time domain earthquake excitation, Incremental Dynamic Analysis (IDA)
Capable of modelling: Wood structure, shear wall and dry wall, but not steel structure.
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Feasibility Study of Hybrid Steel Timber Structures

27. Table 3. SAPWood material model
Wood Shear Wall Hysteretic Models
Linear
Bilinear
SAWS Ten Parameter Model
Evolutionary Parameter Hysteretic (EPHM) Model
Table 3. SAPWood material model
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Feasibility Study of Hybrid Steel Timber Structures

28. Feasibility Study of Hybrid Steel Timber Structures
OpenSees Navigator
Types of analysis: Static, transient and eigenvalue
Capable of modelling:
Linear and non linear material (wood, steel concrete)
Cannot model layered and composite materials
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Feasibility Study of Hybrid Steel Timber Structures

29. Table.4. OpenSees Navigator material model
Uni axial Material
nD Material
BoucWen
ElasticCrossAnisotropic3D
Concrete01
ElasticIsotropic
Concrete02
FluidSolidPorous
Concrete03
J2Plasticity
Elastic
MultiaxialCyclicPlasticity
ElasticNoTension
PlaneStress
ElasticPP
PlateFiber
ElasticPPGap
PressureDependMultiYield
Fatigue
PressureDependMultiYield02
Hardening
PressureDependentElastic3D
Hysteretic
PressureIndependMultiYield
MinMax
Template3DElastoPlastic
Parallel
Series
Steel01
Steel02
Viscous
Table.4. OpenSees Navigator material model
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Feasibility Study of Hybrid Steel Timber Structures

30. Feasibility Study of Hybrid Steel Timber Structures
Shear Wall/Diaphragm
Diaphragms and shear walls, constructed with wood structural panels such as oriented strand board (OSB) and plywood, provide the primary lateral load resisting system in many types of construction.
Fig. 16. OSB Shear Wall
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Feasibility Study of Hybrid Steel Timber Structures

31. Feasibility Study of Hybrid Steel Timber Structures
ANSYS Modelling
Steel frame-OSB shear wall
Type analysis: Static
Purpose of analysis: See the effect of wood shear wall on deformation of the steel frame
Fig.17 Steel frame wood shear wall model
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Feasibility Study of Hybrid Steel Timber Structures

32. Feasibility Study of Hybrid Steel Timber Structures
ANSYS Modelling
Analysis #1= Steel frame w/o shear wall
Analysis #2 = Steel frame + shear wall
Modelling OSB as linear, orthotropic with average properties of the 3 layers
Analysis #3 = Steel frame + shear wall
Modelling OSB as layered element with three linear orthotropic layers
Fig. 18. OSB Shear Wall
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Feasibility Study of Hybrid Steel Timber Structures

33. Fig. 19. Steel frame modelled with Ansys
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Feasibility Study of Hybrid Steel Timber Structures

34. Fig. 20. Steel frame with OSB modelled with ANSYS
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Feasibility Study of Hybrid Steel Timber Structures

35. Table 5. Summary of the result
ANALYSYS #
DEFLECTION(mm) 1
11.05 2
2.07 3
3.1
Table 5. Summary of the result
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Feasibility Study of Hybrid Steel Timber Structures