To assess a structure (whether it is sufficiant or not), the following steps must be followed in sequence:
- Schematising the construction
- Determining the internal forces and moments (= global analysis, elastic analysis)
- Checking the cross-sections (= design):
- Strength
- Stability
- Stiffness
The explanation below covers the design of concrete.
In Diamonds
- Generate at least the combinations ULS FC, SLS RC and SLS QP
. - Determine which analysis type you’re going to use. Based on the analysis type you’ve chosen:
- to (un)check the buckling verification
- the correct value for the accidental eccentricity ea
- if relevant, set the buckling lengths
- Calculate the internal forces F9 or
. - Select the correct concrete standard using the menu Analysis > Concrete standard.
- Click on F2 or
to calculate the reinforcement. The calculated reinforcement will take the strength and stability requirements into account.
Related articles: - Manually verify the punching shear in places with concentrated loads.
- (Optionally) Define practical reinforcement .
- Click on
to calculate the cracked deformation/ cracking widths (= verifying the stiffness).
- Check the option “Compute deformations after creep“.
- If the model contains walls or plates loaded with axial force, also check the option “Extend cracking theory to axial forces”.
- (Optionally) Calculate the cracked deformation in time
.
This calculation is often necessary when the additional deflection (e.g. due to the installation of walls) must be limited. - Redo the elastic analysis (F9 or ) but take cracking into account.
Some cross-sections will be more cracked than others. This will lead to a redistribution of the internal forces. Which in turn can lead to a additional cracking.
- Repeat steps 6 & 7 until the results converge. This is usually already after 1-2 recalculations.
- Verify the cracked deformation (horizontal and vertical)!
- Verify the cracking widths wk (see EN 1992-1-1 Table 7.1N)!
