Preliminary note
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In *Code_Aster*, two types of modeling exist to describe prestress.


*The first method is suitable for describing**adherent prestression**. In this case, the prestress cables are represented by :math:`1D` elements with BARRE modeling. Prestress can be applied easily via operators DEFI_CABLE_BP and AFFE_CHAR_MECA, which make it possible to estimate the variable initial tension profile (N) along the cable according to regulatory formulas (BPEL or ETCC) and to transform it into a load.


*The second method (less proven) is suitable for describing**non-adherent prestress** (typically TGG). In this case, the prestress cables are represented by :math:`\mathrm{1D}` elements with CABLE_GAINE modeling. Cable tension is achieved by simulating the cable tension process via operator CALC_PRECONT, assuming that the cables slide with Coulomb's law-like friction.