General

General

Some general guidelines for troubleshooting the simulation of an extrusion process using adaptive EFG.

    • FAQFAQ
      Participant

      1)Avoid sharp angles in the extrusion die mesh as this may cause difficulty for the billet material modeled with EFG to flow through. Round transitions should be used instead. Another suggestion is to use a smaller value for RMIN in *CONTROL_REMESHING_EFG, or use *DEFINE_BOX_ADAPTIVE with smaller BRMIN and BRMAX around tight geometries of the die or container so that the EFG mesh becomes finer there. 2)The billet/workpiece modeled with adaptive EFG may deform such that it penetrates itself. To prevent this, an AUTOMATIC_SINGLE_SURFACE contact can be defined on the billet. 3)The adaptive time interval may be too big, so the mesh of the workpiece becomes distorted. In this case, decrease the adaptive time interval, using a curve to define the adaptive interval as a function of time, or use the interactive adaptive control of adaptive EFG in *CONTROL_REMESHING_EFG. 4)*CONSTRAINED_LOCAL/GLOBAL are the best ways to constrain surfaces of the adaptive EFG part. *BOUNDARY_SPC_SET can be used to apply constraints too, but the nodal set has to be defined by box (*SET_NODE_GENERAL with BOX as the option in Card 2e). 5)An LS-DYNA MPP solver is recommended.