Week 4

 AIM:  TO CHECK THE GIVEN COMPONENT FOR GEOMETRICAL ERRORS AND MESH WITH THE GIVEN ELEMENT QUALITY CRITERIA

SOFTWARE USED: ANSA  V19. 1.5 (HERE V MEANS VERSION).

ABOUT ANSA: ANSA WAS DEVELOPED BY BETA CAE SYSTEMS, IT IS A TOOL FOR FEA AND CFD ANALYSIS.

ANSA FULLFORM: AUTOMATIC NET GENERATION FOR STRUCTURAL ANALYSIS (HERE NET GENERATON MEANS "MESHING"- IT'S LOOK LIKE A NET  STRUCTURE).

STEPS IN CAE :  THERE ARE THREE STEPS IN CAE.

1) PREPROCESSOR 

2) SOLVER

3) POST PROCESSOR

HERE WE HAVE TO TAKE ANYONE OF THE PREPROCESSOR SOFTWARE , WE USED ANSA FOR MESHING AND QUALITY & MESH QUALTIY.

ANSA PHASES : THERE ARE EIGHT STEPS IN / PHASES IN ANSA.

1) IMPORT A CAD MODEL (OR) GEOMETRY.

2) GEOMETRY CLEANUP

3)SKIN/MID SURFACE GENERATION.

4) SHELL/SOLID MESHING.

5)ELEMENTARY QUALITY CHECK.

6) MESH IMPROVEMENT.

7)APPLY LOADS AND BOUNDARY CONDITIONS.

8)EXPORT INPUT FILE.

1) IMPORT A CAD MODEL (OR) GEOMETRY: FIRSTLY , IMPORT THE CAD MODEL BY USING THE OPTION OPEN IN ANSA IT IS AVALABLE IN FILE AT THE TOP LEFT CORNER. 

BELOW FIGURE SHOWS THE IMPORTED CAD MODEL BEFORE GIVING THE TOPO AND ORIENTATION.

AFTER GIVING THE TOPO OPTION.

 BELOW FIGURE SHOWS AFTER GIVING THE ORIENTATION.

2) GEOMETRY CLEANUP: HERE GEOMETRY CLEANUP IS ONE OF THE IMPORTANT PHASE WE HAVE TO CHECK ANY UNNECESSARY EDGES OR HOLES,CONS OR HOT POINTS .

BELOW ANSA SHOWS SOME ERRORS ABOUT TRIPLE CONS , DOUBLE CONS, CRACKS IN THE CAD MODEL . AS A CAE ENGINEER WE NEED TO REMOVE THOSE ERRORS BY USING AUTO FIX OR MANUAL FIX.

FIRST WE WILL GO WITH AUTOFIX BELOW FIGURE REPRESENT THE ERRORS ARE PRESENT IN THE CAD MODEL.

BY USING THE AUTOFIX OPTIONS ALL THE ISSUES OVER THERE IS RESOLVED SUCCESFULLY. NO NEED TO GO WITH MANUAL FIX. SOMETIMES ANSA FACE TROUBLE WITH AUTO FIX IN THAT TIME WE NEED TO GO WITH MANUAL FIX.

BELOW FIGURE REPRESENT THE CHECK MANAGER.

BY GIVING THE PERIMETER LENGTH TO 1 INSTEAD OF USING FINE COMMAND.

METHODOLOGY USED FOR TAKING MIDSURFACE: HERE A LOT OF FEATURES AVAILABLE IN THIS BOTTLE CAP MODEL . IN ANSA THERE ARE TWO TYPES FOR TAKING MID SURFACE.

1) AUTO MIDSURFACE.

2) MANUAL MIDSURFACE.

I AM USING MANUAL MID SURFACE ,THE REASON IS, IN THIS MODEL A LOT OF FEATURES AND DIFFERENT FACES ARE AVAILABLE SO IT IS DIFFICULT FOR ANSA TO TAKE MID SURFACES ESPECIALLY LIKE THESE MODELS. SO I AM TAKING "MANUAL MIDSURFACE METHOD".

BELOW FIGURE REPRESENT THE MID SURFACE OF BOTTLE CAP MODEL.

CAPTURING MIDSURFACE FROM DIFFFERENT SIDES.

4) SHELL/SOLID MESHING: AFTER SUCCESSFULLY TAKING THE MID SURFACE OF A GIVEN COMPONENT THEN PROCEED TO MESHING.

BY USING MESH WE HAVE TWO BEST OPTIONS.

1)BEST MESH 

2) SPOT MESH.

RANDOMLY I USING BOTH BASED ON SHAPE AND IMPORTANCE.

BELOW FIGURE REPRESENT ABOUT HOW THE MESHING COMPONENT LOOKS.

DURING MESHING WE HAVE TO IMPROVE THE MESH FLOW FOR BETTER RESULTS . IN THIS CONDITION WE  HAVE TO USE TWO OPTIONS MAINLY .

1)SMOOTH : IT SMOOTHEN THE MESH FLOW IT LOOKS COORECT.

2) IMPROVE: THE NAME IT  TELLS ABOUT THEIR FUNCTION , IE IT IMPROVE THE MESHFLOW.

FOR RANDOMLY WE USE PASTE OPTION FOR REMOVING THE TRIA AS MUCH AS POSSIBLE.

TO CHANGE THE DIRECTION OF TRIA AS WE WANT , BY USING THE SWAP OPTION .

5)ELEMENTARY QUALITY CHECK: IT CONSIST OF JACOBIAN, TRIA PERCENTAGE, MIN LENGHT , MAX LENGTH , ASPECT AND MUCH MORE.

DEPENDING UPON THE RESEARCHERS CRITERIA WE HAVE TO ENABLE AND DISABLE THOSE QUALITY CHECKS.

BELOW FIGURE SHOWS THE QUALITY CHECKS OF ANY COMPONENT. 

BELOW FIGURE REPRESENT THE MESH QUALITY.

6) MESH IMPROVEMENT: HERE I ALREADY EXPLAINED IN BEFORE PAGE WE HAVE TO USE IMPROVE, SMOOTH, SPLIT, SWAP, JOIN, RECONSTRUCT FOR MESH IMPROVEMENT.

RESULT:  BELOW REPRESENT THE RESULTS OF A GIVEN BOTTLE CAP COMPONENT.

                                 SHELL

                                 QUADS         :  7377

                                 QUAD%       : 97.14%

                                 TRIAS          :  217

                                 TRIA%         : 2.86%

                                 TOTAL          : 7594

                                 OFF             : 100

                                 OFF%          : 1.32% .