Week - 5 - 2D meshing for Plastic components

Report on Generating 2D mesh and mid-surface after geometry clean-up of symmetry bottle cap model (plastic component) as per given mesh quality criteria by using ANSA software. (Week 5 challenge.)

Objective:

The main aim is to generate the 2D mesh of symmetry bottle cap (plastic component) by taking mid-surface of the same using efficient method in ANSA Software. Also the meshing has to be done under given quality criteria.

Procedure with CAD model images:

• The given CAD model from Design team.

As shown in figure below the given cad geometry needs to do geometry and topology clean up.

Fig. 1: GIVEN CAD MODEL OF SYMMETRY BOTTLE CAP (PLASTIC COMPONENT).

• After importing .igs file in ANSA, observation found that 12 unchecked areas were present where geometry needs to be check for clean-up.
• The fine command is used to gain the original shape of geometry. Half of the unchecked areas got cleared after getting the original shape of geometry.
• By Starting with checking single, double and triple cons. I have used topo command to clear unnecessary single cons and, triple cons are releases using release command.
• In some cases new faces are assigned where faces was missing. (For this new option is used which is available in faces group as shown in fig. below.)

Fig.2 CAD GEOMETRY AFTER CLEAN UP AND REFINEMENT.

Fig.3 GEOMETRY PRESENTATION WITH CHECK MANAGER EXECUTION.

• First I tried to use automatic middle-surface mesh generator to reduce processing time as shown in fig below.

Fig.4 AUTOMATIC MIDDLE-SURFACE MESH GENERATOR METHOD.

• The result of this method gives some warpage, dis-continuity and missing of surfaces as shown in fig.5 below.

Fig.5 ACHIEVED MID-SURFACE USING AUTOMATIC MIDDLE-SURFACE MESH GENERATOR METHOD.

• For getting better mid-surface, here I have used multiple commands for different faces and feature areas.
• The faces which are having same thickness throughout a face area, where I have used offset command to get mid-surface. And the middle command is used where surfaces are having varying thicknesses.
• For getting middle of rectangular teethes, first took middle of two edges using middle command which is available in curves option and other single edge is projected over mid-surface of placing surface. Then the new face has been created using two edges by applying new face command which is available in faces group.

Fig.6 ACHIEVED MID-SURFACE OF TEETH.

• After getting mid-surface of single teeth the transformed rotation operation has been performed for achieving mid-surface of all teethes.
• For the same centre points were created using points ‘ON COG’ command available in point group.
• The fig.9 shows that, mid-surface of all teethes have been achieved successfully using transform rotation operation.

Fig.9 THE TRANSFORM ROTATION OPERATION FOR MID-SURFACES OF TEETHES.

• The fig.6 shows below the archived mid-surface using manual method.

Fig.6 ACHIEVED MID-SURFACE USING MANUAL METHOD.

• As shown in fig.6 above, the ribs areas which are having varying thicknesses are performed cut faces operation to assign different thickness for different areas of rib. (as per guide line of challenge.)
• Similarly for the teeth’s cut operation has been performed to achieve thickness variation as shown in fig.7 below.

Fig.7 VARYING THICKNESS AREAS OF RIBS AND TEETHES.

• The individual separate properties were assigned for different areas of a feature having different thickness of extracted mid-surface using set PID option which is available in faces group and the thickness is given for the same.

Fig.8 MID-SURFACE WITH SEPARATE PROPERTY ID.

• Before going for meshing check geometry has been executed as shown in fig below.

Fig.9 EXTRACTED MID-SURFACE WITH CHECK MANAGER EXECUTION.

• As an input data the given mesh parameter and quality criteria has been set for meshing.

Fig. 10. GIVEN QUALITY CRITERIA.

Fig.11. GIVEN MESH PARAMETER.

• The meshing started by providing perimeter length as target length using length command which is available in perimeter group in meshing module.
• The Best mesh command used which is available in mesh generation group.
• The reconstruct mesh option were used which is available in shell mesh Group for better meshing results.
• Cut option used which is available in macros group to compromise feature areas like fillet to achieve mesh quality criteria and to get meshing to be done.
• Split and swap options were used which are available in element group for avoiding apposite trias and getting better mesh flow.

Fig .12 SYMMETRY BOTTLE CAP MESHED WITH GIVEN QUALITY CRITERIA.

• For the thickness verification, the operation Performed like “draw shell as solid” to compare it with the parent geometry.

Fig. 13. SYMMETRY BOTTLE CAP MESHED PERFORMED “DRAW SHELL AS SOLID”.

Results:

The geometrical clean up, mid-surface extraction and 2D meshing of symmetry bottle cap (plastic component) has been successfully carried out using ANSA Software. Also the assigned thickness to the mid-surface have been compared with the parent geometry by performing draw shell as solid.

Final model image:

Fig .14 FINAL MESHED MID-SURFACE OF SYMMETRY BOTTLE CAP.

NOTE: SINCE IMAGES ARE NOT UPLOADING HERE KINDLY REFER ATTACHED PDF FILE OF REPORT FOR IMAGES.