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FixLine Command

Nodal and element face boundary conditions in FEA analyses can be applied to nodes or elements by using a series of FixLine commands. There are two versions of the command. The first one selects a line through the mesh.

FixLine (x1),(y1),(x2),(y2),<(tol)>
  (Displacement and Load)
  (optional Rotate and/or Select command)
EndFixLine

All nodes close to that line can be assigned load or dislacement conditions or rotated for skewed boundary conditions. The second version selects a previously defined Path:

FixLine (id)
  (Displacement, Load, and Stress commands)
  (optional Rotate and/or Select command)
EndFixLine

All nodes or element faces along that path can be assigned nodal load or displacement conditions, rotated for skewed boundary conditions, or assigned stresses on element faces. The parameters int he above commands are:

Within FixLine blocks, there can be Displacement and Load commands to set displacements or loads in the x and/or y direction, a Rotate command to rotate the nodes for skewed boundary conditions, Stress commands to apply normal and/or tangential stresses on element faces, or a Select command to select nodes for conditional output of results. All nodes within a distance specified by (tol) of the selected line or along the defined path (id) will be assigned each specified nodal boundary condition or rotated.

Stress boundary conditions can only be applied along paths specified by their (id). Furthermore, You cannot set Stress boundary conditions along interior paths; they can only be assigned to paths on the edge of the mesh.

Notes

  1. When doing axisymmetric FEA, nodes at r=0 will automatically be set to zero velocity in the r directions. You therefore need not set those conditions.
  2. The FixLine command is only allowed for FEA analyses.