Week - 4 - 2D meshing for Plastic components

OBJECTIVE :

To check for the geometrical errors and perform mid surfacing by suitable mid surfacing techniques for the given model. Also to assign PID and thickness for all the mid surfaces ans mesh the same with given element Quality criteria.

PROCEDURE :

• The given geometry model is initially imported to the ANSA window and the model is checked for the geometrical errors.
• The geometrical/topologcal errors are listed out using the check geometry option in which the needle faces, unchecked faces, collapsed cons etc are noted and fixed.
• The other geometrical errors are fixed using the suitabe method and the other errors mostly occur are unnecessary hotpoints, improper extended surface, unwanted cut regions on the surface etc.
• Next to topology cleanup, midsurfacing is performed using the offset option / middle surface option based on the region operated.
• For the purpose of creating midsurface of ribs , the middle option in curves is used to create the mid curve and then the mid curve is projected to the midsurface of the geometry. The midsurface of ribs are formed using the new surface option using the cons/curves created.
• The midsurfaces of rib which do not intersect with the midsurface of the geometry are made to intersect using the extend option.
• In offset option, the offset distance is measured and fed in the distance to be given for offset operation. As the midsurfacing is done manually the surfaces are taken in groups and operated.
• The midsurface extracted are assigned to a separate PID created such that midsurface can be easily isolated and meshed.
• Then the perimeter length (target element length) is assigned to the midsurface and the quality criteria & mesh parameters are also assigned for the purpose of meshing.
• Now the middle surface extracted is divided into regions such that the mesh flow is proper. The meshing is carried out using the best mesh method and reconstructed if the mesh flow is to be reworked.
• The mesh flow is made fine using the smooth option such that the flow is not distracted from one region to the other.
• The given model is now midsurfaced and meshed. Finally the elements are assigned for thickness.
• Thus the given model is successfully done on midsurfacing and meshing under the given quality criteria.

MODEL IMAGES :

BOTTLE CAP CAD MODEL :

MESHED MODEL :

THICKNESS ASSIGNED :

CONCLUSION :

Thus the given model is checked for the geometrical errors and mid surfacing is performed by suitable mid surfacing techniques. Also PID and thickness are assigned for all the mid surfaces and meshing the same with given element Quality criteria is done.