3. Generalities#

This operator is a obligatory point of passage for static substructuring or for a structural modification calculation by condensing the measurement.

For static substructuring, it is used:

  • to define a macro-element (keywords: DEFINITION and EXTERIEUR),

  • to request the condensation of the stiffness (or mass) matrix,

  • to define (and condense) the associated loads; the user can name one or more load cases on this occasion.

These 3 steps can be done in a single call to MACR_ELEM_STAT. But they can be done in several times thanks to the use of the keyword « reuse » (enrichment of the macr_elem_stat). The definition step must be carried out first. The condensation of the mass must take place after the condensation of the stiffness.

For structural modification, it is used:

  • to define a macro-element (keywords: DEFINITION and EXTERIEUR),

  • to request the expansion and condensation of the measurement in order to arrive at condensed stiffness and mass matrices.

The macr_elem_stat is a data structure that contains:

  • its references: model, cara_elem, cham_mater, charge,

  • its topological description: the external nodes,

  • its condensed matrices (stiffness, mass, … ),

  • a list of named condensed loads (for static substructuring).

The use of all static substructuring operators is described in the instructions U2.07.02, and the structural modification process is described in the instructions U2.07.03.