Response spectrum generator according to STN (Slovak standard)

Procedure to input a new STN seismic spectrum

  1. Expand branch Libraries of the main tree menu.
  2. Expand sub-branch Loads.
  3. Start function Seismic spectrum to open the Seismic Spectrum Manager.
  4. Click button New.
  5. In combo box Input type select option STN - Slovak standard.
  6. Review and, if required, adjust the spectrum parameters.
  7. Click button Code parameter to review or modify the code-defined parameters of the spectrum.
  8. Confirm the code parameters with OK.
  9. Click OK to confirm the spectrum.
  10. Close the Seismic Spectrum Manager.

Spectrum definition and code parameters

A response spectrum can be defined according to STN by selecting STN - Slovak standard as Input type.

Max frequency & Step

The values of the spectrum are generated between a maximum period of 4 seconds (=0.25 Hz) and the input maximum frequency, using the input Step value.

Code parameters

This button opens the dialogue defining the code-dependent parameters.

coeff accel. ag

Value of the design acceleration expressed as a multiple of the acceleration of gravity g

ag - design acceleration

Design ground acceleration on type A ground

eta damping coefficient

Damping correction coefficient (default = 1.0)

ksi - relative damping coefficient

Relative damping in % (default = 5%)

q - behaviour coefficient

Behaviour coefficient (default = 1.0)

Subsoil type

Ground type (A, B, C, D)

Theoretical background

Spectrum formulation TO DO

Subsoil fa [Hz] fb [Hz] fc [Hz] fd [Hz] ka kb kc kd ke α
A 35.0 10.0 3.0 0.8 12.0 2.4 0.8 1.0 1.0 0.6988
B 35.0 9.0 1.57 0.5 8.5595 2.2 1.4 2.8 0.95 0.6183
C 35.0 8.0 1.0 0.33 6.1607 2.0 2.0 6.0 0.9 0.5410
D 35.0 8.0 0.8 0.25 6.1607 2.0 2.5 10.0 0.9 0.5410