4. Code_Aster behavior relationships#

In the*Code_Aster* two behavioral relationships associated with natural creep are introduced:

  • BETON_GRANGER_V

  • BETON_GRANGER

The first takes into account all the effects (humidity and aging), the second does not take into account the phenomenon of aging. They are available in 2D and 3D modeling and plane constraints.

The various parameters of the model are entered in DEFI_MATERIAU, under the keywords BETON_GRANGER, V_ BETON_GRANGER and ELAS_FO.

  • The \(2\mathrm{\times }8\) constants characteristic of the creep function of the generalized Kelvin model \({J}_{s}\), \({\mathrm{\tau }}_{s}\) are specified under the keyword BETON_GRANGER, whose use is common to the two behavioral relationships BETON_GRANGER and BETON_GRANGER_V.

  • If we use the aging behavior relationship BETON_GRANGER_V then we also fill in the keyword V_ BETON_GRANGER the aging function \(k({t}_{c})\).

  • The desorption curve, required for the two behavioral relationships BETON_GRANGER and BETON_GRANGER_V, is entered under the keyword ELAS_FO.

    Details of the keywords and operands are provided in the table.

Keyword

Explanation

Operands

BETON_GRANGER

The \(2\mathrm{\times }8\) constants characteristic of the creep function of the generalized Kelvin model: - \({J}_{s}\) flexibility of the \(s\) chain - \({\mathrm{\tau }}_{s}\) channel delay time \(s\)

J1: \({J}_{1}\) TAUX_1: \({\mathrm{\tau }}_{1}\) … Day 8: \({J}_{8}\) TAUX_8: \({\mathrm{\tau }}_{8}\)

V_ BETON_GRANGER

Aging function

FONC_V: \(k({t}_{c})\)

ELAS_FO

  • The sorption-desorption curve giving \(h\) as a function of the water content \(C\)

FONC_DESORP: \({C}^{-1}\left(C\right)\)

Table 4-1. Fill in the parameters in DEFI_MATERIAU.