Best Practices Magazine - issue nº1 - English

Our experts I Structural Calculation
lationship, the need to perform a second
order calculation will be determined.
Individual analysis: verifying
elements
In the verification of the different elements
that make up the structure the following
concepts, among others, must be taken
into account:
Uprights - Frames - Anchorage plates
- Upright mainly function by compression
and flexion.
- The use of the reduction factor for buckling,
obtained by laboratory testing or
by using theoretical formulas.
- The internal forces obtained from the
down-aisle and cross-aisle calculations
will be jointly perpended.
- Axil force on the diagonals of the
frame.
- Axil force and momentum on uprights’
footplates.
- Axil and shear force on fastening anchorage
to the slab.
Beams - Connectors
- Working primarily with bending and
shearing forces.
- Buckling (deflection) is limited to a maximum
of L/200. Occasionally, for certain
installations smaller value deflections
are required.
So that the conventional
pallet racking function
safely, it is fundamental
to know the structure
you are working with,
the preventive actions
that exist and the safety
measures to keep in mind.
- Consideration of the cross-aisle forces
of location.
- Verifying the shear force and deflection
in the endplate.
Blocks of bracing - Vertical and horizontal
bracing - Spacers
- The brace diagonals work exclusively on
axil force.
- Verification of the deflection and shear
forces on the elements that connect the
diagonals of the vertical bracing to the
frames (bracing spacers).
- The actions of the bracing increases the
forces on the uprights and beams that
form part of the block of bracing or that
are adjacent to it.
- The eccentricity of the actions of the
vertical bracing in respect to the racks
requires a study of the torsion behaviour
of the elements that form part
of the block of bracing, as well as the
racks.
Actions
There are different types of actions that
may affect the strength and stability of
the racks, so that it is also imperative to
contemplate them when setting up an
installation of this kind. The actions on the
racking are classified into several groups:
Permanent actions
- Weight of the racks.
- Permanent loads and various equipment
supported by the racking.
Variables actions
- Weight of the pallets.
- Weight and actions due to mobile loads
on platforms and walkways.
- Actions due to the location of the pallets
(vertical + horizontal).
- Actions on the positioning profiles.
- Actions due to storage equipment
guides.
- Actions due to the imperfection in the
elements and assembly.
- Other actions arising from national regulations
(wind, snow, etc.).
- The weight of the pallets together with
the general imperfection deemed as a
156 Best Practices