Double tapered, curved, or pitched-cambered beams
Cross-sectional Inputs
All references to EN 1995-1-1:2004
unless otherwise stated.
This refers to glulam or LVL beams of a rectangular cross-section whose geometry changes symmetrically along its axis. These can be double tapered, curved, or pitched cambered beams.
The design is done for bending about the y-y axis, taking into account the effect of local bending, shear, and tensile (perpendicularly to the grain) stresses at the apex, according to Clause 6.4.3
.
Timber Type
The Timber Type of the cross-section. Note that only glulam and LVL timber types are supported for this design.
Beam type
The user can selected between double tapered, curved, and pitched cambered beams.
Beam span l
The span of the beam, in mm.
Width bThe width of the cross-section, in mm. Depth hThe depth of the cross-section, in mm. Depth h_{ap}The depth of the cross-section at the apex, in mm. |
Factor k_{vol}
The volume factor k_{vol} is required for Kerto-Q LVL where all veneers are not parallel to the beam axis.
Angle of the taper α_{ap}
The angle of the taper in the apex zone for a double tapered or pitched-cambered beam, in degrees.
Angle βThe angle of a curved beam in the middle of the apex zone, in degrees. Inner radius of curvature r_{in}This is the radius of curvature of the beam, measured to the centre of gravity of the beam, in mm. |
Lamination thickness t
The lamination thickness, in mm.
Area reduction
The area reduction ΔA refers to reductions in the nominal cross-section size that have to be taken into account in the calculation of the member strength (e.g. holes from fasteners) according to Subclause 5.2(2)
.
It should be given as a percentage of the total nominal area of the cross-section.
Section modulus reduction
The section modulus reduction ΔW refers to reductions in the nominal cross-sectional modulus that are to be taken into account in the calculation of the member strength (e.g. holes from fasteners) according to Subclause 5.2(2)
.
It should be given as a percentage of the total nominal section modulus of the cross-section.
Contribution of cross-section size on the determination of member strength properties
Includes factors k_{h} for the calculation of the member strength in solid timber, glulam and LVL, according to Clauses 3.2
, 3.3
, and 3.4
.
In the case of an LVL member under tension, the member length is also required.
Contribution of the load distribution system in the member strength properties
Includes factor k_{sys} for the calculation of the member strength, according to Clause 6.6
, for a member that functions as part of a continuous load distribution system.
Note that Subclause 6.6(3)
states that the strength verification for a continuous load distribution system should be carried out assuming short-term load duration.