Frequency sweep analysis using code_aster

Frequency sweep analysis using code_aster

code_aster offers numerous dynamic analysis options: full transient (see “Dynamic stability of 3d-printed device“), modal, spectral and harmonic. This post presents an example of the latest applied to a 8 stories building.

Three first natural frequencies of the building

The harmonic analysis can be performed directly in the physical space, or by the modal superposition method – which could be useful for large problems (superposition of modes of the full structure or a series of sub-structures).

The macro commande DYNA_VIBRA gathers many of the dynamic options under a single command, e.g.:

Haro = DYNA_VIBRA(
  TYPE_CALCUL='HARM', 
  BASE_CALCUL='PHYS',
  MATR_MASS=M3,
  MATR_RIGI=K3,
  MATR_AMOR=C3,
  LIST_FREQ=listfreq, 
  EXCIT=_F(VECT_ASSE=F3, COEF_MULT=1.0),
);

The new DEFI_LIST_FREQ command creates a list a frequencies to sweep with an automatique refinement around the natural modes of the structure.

For training or consulting using code_aster, contact us.

Harmonic response of the building from 0 to 10 Hz