3. Principle of macro-control

The POST_DECOLLEMENT operator performs the following actions:

• calculates the total surface of the frame: it uses the POST_ELEM/INTEGRALE command to determine the area of the group of elements provided in the GROUP_MA operand. This calculation requires the creation of a 2D model reduced to the group of elements GROUP_MA and the creation of a unit field at the nodes of this group before being integrated.

• goes through the moments of the SD Result provided to operand RESULTAT for:

• extract the component NOM_CMP from the displacement field NOM_CHAM at the current moment,

• define a nodal field whose values are equal to 0 to the negative values of NOM_CMP in field NOM_CHAM, and 1 to strictly positive values,

• determines the area of the floor whose values in the previous field are equal to 1,

• calculates the ratio of areas to obtain the percentage of radiation/ground separation.

If this operator was developed to calculate the surface area of separation of a raft on the ground in soil-structure interaction calculations, it can be used for other purposes, on fields other than a field of displacement.