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Calculate the thermal response with nonlinearities of behaviors and boundary conditions.

The heat equation is solved under an evolutionary regime (unless no list of moments is provided, only the steady state is then calculated). Nonlinearities come either from behavior (characteristics of the material depending on temperature), or from boundary conditions (radiation in an infinite medium, non-linear flow, thermal source dependent on temperature). An enthalpy formulation was chosen in order to more easily take into account the phase changes of the material.

The evolutionary calculation can be initialized at the first moment in three different ways (keyword TEMP_INIT):

• at a constant temperature,

• by a temperature field, defined in advance, or extracted from a previous calculation,

• by a stationary calculation.

This operator also makes it possible to solve drying problems (non-linear) by solving the heat equation where the concentration of water \(C\) is assimilated to a temperature, for resolution. In this case, thermal conductivity is the diffusion coefficient, which is non-linear in \(C\) and is a function, possibly, of a temperature calculated beforehand.

To model the hydration of concrete, the operator also allows you to add a source term that is a function of the hydration variable to the heat equation. This term is then given by an evolution equation where temperature intervenes.

The concept produced by the operator THER_NON_LINE is of the evol_ther type as for a linear analysis by THER_LINEAIRE [U4.54.01].

When a calculation of the sensitivity of the result with respect to a parameter is requested, as many evol_ther data structures as required parameters are produced.