Timber joist floor slabs (CYPECAD module)

INDEX

• General properties of timber elements in CYPECAD
  • Implemented codes
  • Section series
  • Definition of the material, service class and live load duration
• Introducing timber joist floor slabs
• Timber joist design (worst case check reports)
• Fire resistance check of timber joists
• User license
• Versions and modules of CYPECAD
  
  

General properties of timber elements in CYPECAD

 

CYPECAD allows users to define, analyses and design timber joist floor slabs and timber beams. These structural timber elements are included in the “Timber joist floor slabs” and “Timber sections” modules, respectively.

 

The “Timber sections” module is for use in CYPECAD and CYPE 3D, and allows users to analyse and design structural beam-type timber elements and generic-type timber elements. More information on the “Timber sections” module, for use with CYPECAD and CYPE 3D can be found on the “Timber sections” webpage.

 

 

 

 

 

Implemented codes

The codes implemented for the design and check of the timber joist floor slabs and beams are:

• CTE-DB -SE-M (Spain)
• Eurocode 5
• Eurocode 5 France
• Eurocode 5 Belgium
• NBR 7190:1997 (Brazil)
  
  
  

Section series

To adapt the program to the current market, timber sections have been created, distinguishing between sawn timber and laminated timber, and including the DUO/TRIO series, which are currently very much in use.

Definition of the material, service class and live load duration

 

The data CYPECAD will use to analyse the timber elements (joists, beams and bars of integrated 3D structures) is defined in the “Timber” dialogue box (Project > General data > Timber):

 

• Material properties
  This data is defined individually for beams, joists and bars of 3D structures. The properties that have to be defined vary and the options that are available for each property will depend on the code that is applied:
  
  
  • Type
  • Origin
  • Resistance class
  • Category
    
    
• “Service class” or “Humidity class”
  The service class defined is applicable to beams, joists and timber bars of 3D structures.
  
  
• Duration of loads introduced as live loads
  The duration of live loads which affect timber elements is also applicable to any timber element defined in CYPECAD.
  
  
  
  
  
  

Introducing timber joist floor slabs

 

Users can select timber joist floor slabs in the “Joist floor slabs” menu in the “Panel manager” dialogue box (Slabs > Panel manager > Define panel).

 

The following data must be defined for a joist floor slab:

 

• Section series
  The timber section series to be used in the design of the timber joists is indicated here.
  
  
• Elevation difference
  Is the depth of the space between joists which, for the program, is generic (regardless of its aspect: curved vault, flat ceramic board, etc.) and its height is measured from the top surface of the timber joist up to the level of floor “Z”.
  
  
• Interaxis
  
  
• Maximum depth
  The maximum depth of the floor slab is defined by users and takes into account the height of the space between joists.
  
  
• Concrete volume
  Is only used for the take-off
  
  
• Self-weight of the floor slab
  
  
  
  
  
  
  

Timber joist design (worst case check reports)

The sections that make up the timber joists are designed for simple bending, because due to the rigid diaphragm hypothesis, axial forces and forces in the plane of the floor slab are not considered.

Following this criteria, the program selects the first joist of the selected series that does not fail any resistance or deflection checks, as long as the maximum depth (defined by users) is not exceeded.

From the “Joists” menu in the “Results” tabs, users can access the worst-case report of the joist. This report includes a table with the deflection checks of the timber joists.

 

 

The deflection checks for timber joists are obtained considering:

 

• The deflection limits for the joist
  These limits are indicated in the “Deflection limits in joists” dialogue box (Project > Floor slab options).
  
  
• The active deflection and long-term deflection
  These depend on the construction process and the coefficients which are applied. These are established in the “Active deflection and total long-term deflection – Construction process for joist floor slabs” dialogue box (Project > Floor slab options > Active deflection and total long-term deflection – Construction process for joist floor slabs).
  
  These coefficients take into account the construction process when calculating the active and long-term deflections for concrete, steel and timber joists. Here, users can see the equivalent equation to consider creep in timber joists, which considers the creep coefficients automatically defined in timber design codes depending on their service or humidity class.
  
  More information on the calculation process applied to obtain the active deflection and long-term deflection carried out by CYPECAD can be found by pressing the help button of this dialogue (located in the top right-hand corner of the dialogue box).
  
  

 

Fire resistance check of timber joists

The program carries out the fire resistance check of timber joists using the “Fire resistance check” module, used by CYPECAD and CYPE 3D, and also carries out the check for other structural timber (timber beams and other generic-type timber structural elements), steel and concrete elements.

The data that has to be defined for CYPECAD to be able to check the fire resistance of timber joists and beams is introduced in the “Fire resistance check. General data” dialogue box (Project > General data > Loads > Fire resistance check).

In this dialogue box, users have to define, for each floor group:

 

• The required resistance
• Whether or not there are floor slabs acting as compartments
• The coatings of the structural elements:
  
  
  • Bottom coating of concrete beams and floor slabs
  • Coating of columns, shear walls and walls
  • Coating of steel beams and joists
  • Coating of steel columns
  • Coating of timber beams and joists
    
    

It is possible to defined different data for a specific zone in a group of floors using the options of the Fire resistance window (Groups > Fire resistance from the Beam Definition or Results tab).

More information on this module, for use with CYPECAD and CYPE 3D, can be found on the Fire resistance check webpage.

User license

For CYPECAD to be able to analyse and design timber joist floor slabs, the user licence must include, as well as CYPECAD, the “Timber joist floor slabs” and “Joist floor slabs (generic concrete joists)” modules.

If, users also wish to check the fire resistance of these elements, they must also hold the “Fire resistance check” module permits.

CYPECAD versions and modules

CYPECAD versions

CYPECAD is available in its unlimited version and also in two limited versions called LT30 and LT50, which contain the same tools and module acquisition possibilities, but have the following conditions:

CYPECAD LT50:

• Fifty columns
• Four floor groups (Floor group: floors which are the same and consecutive)
• Total of five floors
• Walls: one hundred linear metres

CYPECAD LT30:

• Thirty columns
• Four floor groups (Floor group: floors which are the same and consecutive)
• Total of five floors
• Walls: one hundred linear metres

Integrated 3D structures of CYPECAD (also LT50 and LT30) is not technically a module. To define these 3D structures in CYPECAD, users must also have the required permits to use CYPE 3D in their user license and, optionally, modules which are exclusive to CYPE 3D.

CYPECAD Modules

The following modules are those that can be acquired together with CYPECAD or CYPECAD LT:

• Steel columns
• Steel beams
• Joist floor slabs (generic concrete joists)
• Joist floor slabs (in-situ, precast and steel)
• Timber joist floor slabs
• Waffle slabs
• Flat slabs
• Punching shear verification (Also operates as an independent program)
• Composite slabs
• Hollow core slabs
• Post-tensioned concrete slabs for buildings
• Shear walls
• Reinforced concrete walls
• Plane stress walls
• Stairs
• Mat foundations and foundation beams
• Concrete block walls
• Interaction of the structure with the construction elements
• Automatic job introduction: DXF, DWG and CAD/BIM models
• Collective protection systems
  

Modules common to CYPECAD and CYPE 3D:

• Concrete columns
• Composite steel and concrete columns
• Concrete beams
• Timber sections
• Pile caps (includes strap and tie beams)
• Baseplates
• Footings (pad and strip) (includes strap and tie beams)
• Advanced design of surface foundations
• Fire resistance check
• Parallel analysis with two multiprocessors
• Parallel analysis with up to eight processors
• Joints I. Welded. Warehouses with rolled and welded steel I sections
• Joints II. Bolted. Warehouses with rolled and welded steel I sections
• Joints III. Welded. Building frames with rolled and welded steel I sections
• Joints IV. Bolted. Building frames with rolled and welded steel I sections
• Joints V. Flat trusses with hollow structural sections
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