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"bcs" block

Boundary conditions are defined in the JSON block "bcs". Each named subobject is one BC block.

json { "bcs": { "fix": { "type": "dirichlet", "dofs": ["ux", "uy"], "bcvalue": 0.0, "side": ["left"] }, "load": { "type": "traction", "dofs": ["uy"], "bcvalue": 0.0, "side": ["right"], "parameters": { "component": 2, "traction": [0.0, 20.0, 0.0] } } } }

Options inside each BC block

  • "type": required string.
  • "dofs": required array of DoF names. Every name must already exist in the "dofs" block.
  • "bcvalue": required number or string. Constant values such as 0.1 are accepted. Time-dependent strings such as "0.1*t" are also accepted by the parser.
  • "side": required array of boundary names.
  • "parameters": optional JSON object for BC-specific data.

The old keys boundary= and value= are no longer valid. The current parser reads "side" and "bcvalue".

Boundary names

"side" names must match the boundary physical names stored in the mesh.

For built-in meshes, the predefined names are: - 1D: left, right - 2D: left, right, bottom, top - 3D: left, right, bottom, top, back, front

For imported meshes, use the physical boundary names from the mesh file.

Supported BC types

text dirichlet rotateddirichlet nodaldirichlet user1dirichlet ... user5dirichlet poisson2dbenchmark neumann nodalneumann pressure traction user1 ... user5

"parameters" is type-specific. For example, upstream examples use: - rotateddirichlet: plane, center coordinates such as y0/z0, and rotation-speed - traction: component and a traction vector