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Initial conditions

Initial conditions Icon toggle

Initial conditions establish the starting state of various parameters in a simulation, such as stress, pressure, and material state. These conditions are essential for setting a realistic baseline for simulations, especially in geotechnical analyses. Please click here The following initial conditions are available:

Initial Void Ratio (\(e\)) Icon toggle

  • Represents the initial void ratio, which is the ratio of void volume to solid volume in the material.
  • Critical for defining the initial state of soil or granular materials.

Initial Stress (\(\sigma\)) Icon toggle

  • Specifies the pre-existing stress state within the model. Please click here for more information.
  • Used to simulate in-situ stresses, such as those caused by gravity or overburden pressure.

Pore Water Pressure (\(p_w\)) Icon toggle

  • Defines the initial pore water pressure of the material.
  • Essential for models involving saturated or partially saturated conditions, such as groundwater or seepage simulations.

Pore Air Pressure (\(p_a\)) Icon toggle

  • Sets the initial pore air pressure.
  • Applicable in unsaturated soil models where air occupies part of the pore volume.

State Variables (SV) Icon toggle

  • Initializes material-specific state variables required by advanced constitutive models.
  • Examples include plastic strain, damage parameters, or internal variables for hypoplasticity.

Contact Icon toggle

Contact defines the initial interaction parameters between surfaces in the model. Proper configuration of contact ensures that surfaces interact realistically during the simulation, reflecting physical behaviors such as friction, separation, and penetration.

How to Configure Initial Conditions

Select Initial Condition Type: - Choose from the available options: Void Ratio, Stress, Pore Water Pressure, Pore Air Pressure, or State Variables.

Define Parameters: - Input the required values specific to the chosen initial condition:

  • Void Ratio: Specify the initial value for void space.
  • Stress: Define the stress tensor components.
  • Pore Pressures: Input the water or air pressure values for relevant regions.
  • State Variables: Set custom variable values as required by the material model.

Assign to Geometry: - Link the defined initial conditions to specific geometry, elements or nodes in the model.