Solver message 312386

Message Text

** ERROR 312386 ** Core shift analysis resulted in excessive displacements. Please check if the constraints are set properly for core shift, then rerun the analysis.

Explanation

A core shift analysis is a static structural analysis of a mold core or part insert body. This requires the body's position and rotation to be defined by assigning adequate constraints onto the body for each degree of freedom (DOF). In total, six DOFs must be defined, including three translational DOFs, and three rotational DOFs. Rotational constraints can be achieved by the use of staggered translational constraints. Failure to set adequate constraints may lead to unrealistic excessive displacements. An example of an adequate constraint setting is as follows:

  1. Pick a first node, fix the translational DOFs in all X, Y, and Z directions.
  2. Pick a second node whose X coordinate does not coincide with that of the first node, and Z coordinate is as close as possible to that of the first node. Then fix the translational DOFs in the Y and Z directions.
  3. Pick a third node, then fix the translational DOF in the Z direction. This node should have the Z coordinate as close as possible to, but not be inline with, the previous two nodes.

Resolution

  1. If a core shift constraint is a spring constraint, check the spring stiffness value. If it is too weak, change it to a more realistic value.
  2. If a one-sided constraint has a free direction, for example +X or -Y, check the mold core or part insert body's movement in that direction. If the body is not constrained by other constraints in that direction, modify the existing constraints or apply new constraints to eliminate free motion in that direction.
  3. For other constraint types, check if all DOFs of the body are constrained by the core shift constraints. If not, apply proper constraints. You may refer to the preceding example for a proper constraint setting.