- Enter the geometry of the structure as you would normally do.
If your model contains multiple independent structures, make one Diamonds-file for each structure.
- Load group and masses
- Click on . Add a load group and select ‘Seismic’ from the list.
- To calculate the response of the structure due to the seismic load, the modal parameters of the structure (eigen modes and -frequencies) must be calculated by Diamonds. These model parameters depend on the stiffness and mass distribution of the structure.
- The stiffness is known by Diamonds. It is in the geometry of the structure.
- The mass distibution is related to the vertical loads (point loads, line loads, surface loads) (0,981kN -> 100kg).
The correlation coefficient φ multiplied by the combination factor Ψ2 (for Eurocode and Eurocode-like standards) will determine the masses.
For example: a life load of 5kN/m will lead to 5kN/m² x Ψ2 x φ = 5kN/m x 0,3 x 1 = 1,5kN/m of mass to be taken into account during the model analysis.
- Define the seismic spectrum: select the load group Seismic from the pull down list and click on . Enter the desired paramters.
Read here how to define a user defined seismic spectrum.
- Generate the combinations . Don’t forget to check the ULS SC combinations.
- Run the analysis . In the tab page ‘Dynamic’ choose ULS FC as reference combination.
- Run the reinforcement calculation , steel or timber design .
Diamonds will take the seismic combinations ULS SC into account.
- Verify the deformations.