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Dynamics
Earthquake Analyses

Option D of STATIK

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The module covers the evaluation of natural vibrations (frequencies and mode shapes) and earthquake analyses using the lateral force method or the modal response specturm analysis.


Mass Model

  • Each dynamic analysis needs a mass distribution, in which all the masses of a structure are combined
  • A mass distributions is handled much like a loading
  • It may contain self masses, line masses and point masses with excentricities
  • Loadings containing only gravity loads can be used as mass distributions
  • Mass distributions may be combined (e.g. of story masses) with graphic display of mass centers

Natural Vibrations

  • Frequencies and mode shapes
  • Tabular output of
    • Eigenfrequencies
    • Modal participation factors for the excitations directions X,Y,Z
    • Eigenmodes sorted after descending effective modal masses
  • Graphic representation of mode shapes (rendered)

Earthquake Analyses

Earthquake analyses can be specified for all kinds of structures. They are automatically generated by building models defined by CEDRUS.

Specra

  • Spectra can be defined by entering the parameters according to the used design code or individually by entering polygonal curves

Equivalence (Lateral) Force Method

  • The method ist useable mainly for building models generated by CEDRUS, especially for the comparison with results from a response spectrum analysis.
  • The fundamental periods can be given or evaluated by the program
  • The used specrum may be reduced to a constant maximum (=plateau) value

Response Spectrum Analyses

  • Superposition of the modal components by the SRSS or the CQC method
  • Combination of the results of two perpendicular excitation directions according to Eurocode or
  • Envelopes of results from several excitation directions
  • Method for evaluation of section force envelopes for one component including the values of the accompanying components (incl. correct sign)

Design of reinforcements (classic) for the design situation earthquake (FAGUS(A) license needed).