Timber Cross Section Verification
Verification of timber cross-sections is carried out for a load of bending moment, normal force and shear force. Verification is carried out for a chosen load or for the critical load. The critical load is the load with a maximum value of utilization.
Cross-section can be checked by these ways:
- Verification according to EN 1995-1-1 (EC 5)
- Verification according to safety factor
- Verification according to limit states
Each cross-section is checked for two types of load:
1. Check for bending moment and normal force
The analysis checks the bending moment stress σm developed at the edge of cross-section given by:
where: | M | - | bending moment |
W | - | elastic modulus of cross-section |
and the normal force stress σn given by:
where: | N | - | normal force |
A | - | area of cross-section |
The normal force can be either tension or compression.
2. Check for shear
The analysis checks the shear stress τ at the cross-section center of gravity written as:
where: | Q | - | shear force |
S | - | 1st moment of area | |
I | - | moment of inertia | |
t | - | width (thickness) of cross-section at its center of gravity |