Interface 2D fault

Type: 210

The element consists of 2, 3, 4, or 5 nodes (line, parabola - DoF 1, 2, 3, 4, 5) relating to one side of the fault (= the structure), and 2, 3, 4, or 5 additional nodes to discretize the flow of water, gas, or temperature inside the fault (DoF 3, 4, 5). It also relates to a predefined foundation.
This element is dedicated to soil mechanics and in particular to structure-structure contact (fault). It includes pressure, friction, flow axial to the fault (water, gas, temperature), flow (water, gas, temperature) transversal to the fault (along the thickness).

Convention: when the element is considered in increasing order of nodes (1 → 2 → 3), the first body is to the left, and the tool or foundation to the right.

This element can be used with mechanical law INTME2 or a classic mechanical law and flow law INTFL2.

The element is compatible with plane stress state, plane strain state, and generalized plane state, as well as axisymmetric state. It can be used for thermo-mechanical analysis with 5 DoFs.

Warning: When using renumbering of the DoFs, only directional renumbering works.

Implemented by: J.P. Radu, 2007 (taken from FAIN2)

Prepro: FAIF2A.F
Lagamine: FAIF2B.F

If the law is INTME2/INTME3:
Stresses (20):

• Pressure
• Tangent stress
• 0
• 0
• Longitudinal water flow,
• Stored water flow,
• “FI” (between Foundation and Inside) transversal water flow
• “IS” (between Inside and Structure) transversal water flow
• Longitudinal gas flow,
• Stored water flow,
• “FI” (between Foundation and Inside) transversal gas flow
• “IS” (between Inside and Structure) transversal gas flow
• Longitudinal thermal flow,
• Stored thermal flow,
• “FI” (between Foundation and Inside) transversal thermal flow
• “IS” (between Inside and Structure) transversal thermal flow
• Longitudinal vapor flow,
• Stored vapor flow,
• “FI” (between Foundation and Inside) transversal vapor flow
• “IS” (between Inside and Structure) transversal vapor flow

If the law is not INTME2/INTME3:
Stresses:

• $\sigma_{11}$, $\sigma_{22}$, $\sigma_{12}$, $\sigma_{33}$ in local axes
• Longitudinal water flow, Stored water flow, “FI” (between Foundation and Inside) transversal water flow, “IS” (between Inside and Structure) transversal water flow
• Longitudinal gas flow, Stored water flow, “FI” (between Foundation and Inside) transversal gas flow, “IS” (between Inside and Structure) transversal gas flow
• Longitudinal thermal flow, Stored thermal flow, “FI” (between Foundation and Inside) transversal thermal flow, “IS” (between Inside and Structure) transversal thermal flow
• Longitudinal vapor flow, Stored vapor flow, “FI” (between Foundation and Inside) transversal vapor flow, “IS” (between Inside and Structure) transversal vapor flow

Internal variables:
The first values are the ones relating to the law
For INTME2/INTME3, this will be: plasticity indicator, dissipation, fault closing $V$, fault opening $D$).
The 6 next values correspond to the contact geometry. They are:

• The segment number of the foundation in contact
• The interpenetration distance
• The jacobian
• NOCO the contact indicator given by CALFON
• The relative tangent rate
• The relative sliding

The last values are those relating to the flow law; for INTFL2, they are:

• The relative permeability to water
• The relative permeability to gas
• The porosity
• The saturation to water
• The suction
• The specific mass of water
• The specific mass of gas
• Peclet number
• The water content
• The specific mass of vapor
• The vapor pressure
• The relative humidity
• The mass of liquid water per unit volume
• The mass of dry air per unit volume of soil
• The mass of vapor per unit volume of soil
• The intrinsic longitudinal permeability
• The gas saturation
• The partial pressure of hydrogen (not used)
• The water pressure inside the fault
• The gas pressure inside the fault
• The temperature inside the fault
• The transversal transmissivity of water
• The transversal transmissivity of gas
• The thermal transversal transmissivity
• The thermal conductivity