Seismic behavior of a structure
=====================================




Definitions
-----------

The analysis of the seismic behavior of a structure consists in studying its response to an imposed movement: an acceleration, in its various supports. The imposed acceleration is a time signal :math:`\gamma (t)` called an accelerogram (cf. [:ref:`Figure 1.1-a <Figure 1.1-a>`]).


.. image:: images/10000200000003A60000029AC5E16151C961C123.png
    :width: 5.3717in
    :height: 2.102in


.. _RefImage_10000200000003A60000029AC5E16151C961C123.png:


.. _Ref456693275:


.. _Ref456693271:

**Figure** **1.1-a:** Accelerogram LBNS

The seismic movement considered in the calculation is either a real accelerogram known and read by the operator LIRE_FONCTION [:external:ref:`U4.32.02 <U4.32.02>`] or a synthetic accelerogram calculated directly in the code, for example with the procedure FORMULE [:external:ref:`U4.31.05 <U4.31.05>`].