Project 1 - 2D meshing on the instrumental Panel

                                                                                                               PROJECT                                                                                       

                                                                                      2D meshing on the instrumental Panel

OBJECTIVE

• Importing instrument panel geometry into ANSA
• Clean up the geometry until no topological error is found
• Generate midsurface for the whole component inclusong features
• Mesh the component using manual mesh with given quality criteria
• Improve the mesh flow and solve off elements

QUALITY CRITERIA

                                                                                           

ABSTARCT

In this project ANSA Preprocessor is used to generate midsurface using various options like casting ,offset,middle .Created 2D interpolation of the parent geometry .Extended midsurface in order to connect all the generated midsurfaces .Mesh the component using spot with given quality criteria.Cleared off elements without any kinds or raised edges.

METHODOLOGY

• Import CAD geometry into ANSA
• Do geometry check and clear all the errors
• Generate midsurface and assign different PIDs for parent geometry and midsurface 
• Setup quality criteria and mesh parameters 
• Meshing and improvement of the mesh

                                                                    

A dashboard  is a control panel usually located directly ahead of a vehicle driver display instrumentation and controls for the vehicle operation .These days car dashboard may include so many indicators like speedometer ,tachometer, odometer ,fuelguage ,turn indicators , gear indicators ,gearshift position indicator,seat belt indicator ,engine malfunction lights.Other features may include a guage for alternator voltage,Indicators  for low fuel ,low oil pressure ,low tire pressure and faults in the airbag system ,lightning controls , safety system entertainment equipment ,navigation system.

PRODECURE

• Import the geometry into ANSA and do topo to stitch the surfaces .Assign PID for the whole geometry

                                                                 

• Measure all the features so that when you assign PIDs it will be easy to define different thickness for features like small ribs ,big ribs , dog houses

                                                           

• Clean the geometry using check manager .Enable unchecked faces , collapsed cons , triple cons , needle faces , overlapped faces, cracks , single cons .Clear all these issues until no error is found .One can use fix option in ANSA to clear all the errors automatically .However sometimes manual intervation is required for fixing some errors.

                                                                     

MIDSURFACE GENERATION FOR BIGGER ONE

• Casting and skin options havent generated best results in midsurface generation .Therefore have done the midsurface generation manually
• First generate midsurface for bigger part so that other small features canbe extended on to it.Using offset option pick the bigger surface using feature area to generate midsurface

                                                             

• Select the side which has less features so that the midsurface generated will be accurate isolate generated midsurface assign PID and thickness to it.

                                                                

MIDSURFACE GENERATION FOR SMALL RIBS

• Use middle option and select both sides of the rib.Then a midsurface will be formed .Like this generate midsurface for all the ribs.Dont forget to give seperate PID and thickness for all the features
• Now extend the midsurface of the ribs on the bigger midsurface generated in the earlier step.One can check the thickness by giving transperacy to the parent geometry and enabling draw shell as solid in presentation parameters.

                                                                                 

MIDSURFACE GENERATION FOR LONG RIBS

• Midsurface for long ribs on the geometry can be generated using faces a offset option .Measure the thickness and give offset value in the desired direction
• Similarly extend the midsurface of the long ribs  on the bigger midsurface .Also check the thickness by giving transperacy to the parent geometry and enabling draw shell as solid in presentation parameters.

   

MIDSURFACE GENERATION FOR DOG HOUSES

• Usually the doghouses consist of cylindrical surface .For these cylindrical surfaces we cant generate exact midsurface and volume mesh is not preferd as these dog houses are more in geometry .So i have captured these cylindrical surface as two intersecting rectangular ribs.
• Using Cons 2 curve option i have connected the curve which is created on the cylindrical feature of parent geometry and rib using faces a new  fitted surface option

                                                                            

• Select one side of rib and the curve to create rib for one side .Similarly create mid on the other side like cross symbol.This represent one single dog house.After creating surface on the both sides extend all the required surface to the  main midsurface.Also use intersect option to form triple can in the middle.

                                                                                        

• Now to attain the same elevation as a parent geometry .I have extended the midsurface of the dog houses on the surface of the parent geometry .Triple Cons will be formed if extend them prefectly

                                                                           

• Similarly generate midsurface for all the  dog houses  and extend that on the parent geometry to attain perfect shape for the midsurface .After achieving the elevation release all the cons and do topo again so that midsurface will be releaved from parent geometry.

                                                                       

• First generate midsurface for one dog house and check using transperacy mode and enable draw shell as solid .In this manner one can easily check whether the midsurface and thickness capturing is done perfectly or not

                                                    

MIDSURFACE GENERATED USING CASTING

• For some features in the center of instrument panel i have generated midsurface midusing casting option

                                                       

• Assign minimum thickness target element length  and run on selected features .Casting always generate mesh  along with midsurface .

                                        

• I have attached of the complete midsurface generated below after connecting all the features together.

                                                 

MESH AND IMPROVING MESH FLOW

• In this midsurface there are lot of double cons nearer to each other .There fore  lot of topological clean up should be done before starting mesh.
• For this dashboard manual mesh is preferred as it has more features connected with each other .I have used spot mesh option and meshed region by region manually.
• There will be some off elements generated at some places where triple converge.

                  

RECONSTRUCT AND SMOOTH

• Used smooth option in order to clear some off elements at coverging places.

                                     

                                                                            

• For better mesh flow reconstruct option can be used .Removed opposite trias and trias at the edges using options like swap spilt and paste options

                                                                         

PROBLEMATIC FACES

• Problematic faces are the areas where lot of double  cons present one surface .Even if you cut these cons and mesh them off elements will be generated.

                                                               

                                                           

• So delete these faces and create new surface so that unneccassary double cons will be eliminated automatically .As a result off elements will also be rectified also mesh flow will be smooth.

DEFEATURING

• De featuring can be done at some corners to remove off elements where there is less space between the nodes .Here the length between node is which is less than minimum length given by qulaity criteria .Therefore defeaturing has to be done in this region.

                                  

                                                                     

• This defeaturing can be done simply creating user cuts and deleting the required regions

KINKS AND RAISED EDGES

• Align option can be used in order to eliminate kinks and raised edges.First select source node raised edge or link

                                                 

• Select three points on the plain surface on which the source node must be moved.

                                                         

• In this manner raised edges and kinks can be eliminated easily .One can also use origin option to remove raised edges and kinks.

                                                                         

• In this project element is converted into 42599 elements in total
• Quad elements  40520 which is 95.12%
• Tria elements 2079 which is 4.88% .There are some off elements.

                                

                                             

OUTCOME

• Able to do topological clean up with no errors
• Assigned seperate PIDs for different surfaces
• Able to generate midsurface for complex geometry with varying thickness
• Aware of the all the quality criteria and quality parameters during mesh generation
• Understood about mesh generation and implementation mesh generation for complex geometry
• Learned how to improve mesh flow and remove trias to achieve better mesh flow
• Understood all the concepts regarding midsurface generation and meshing  in ANSA

CONCLUSION

In this project  have generated midsurface using different options available in ANSA .Able to  defeature and do line adjustment in some areas .Did topological clean up understood about transperacy mode and the concepts related in generating midsurface for the different features.Able to achieve better mesh flow using smooth reconstruct  swap paste  move options .Eliminated  kinks and raised edges. Successfully generated midsurface and meshed whole instrument panel in ANSA

 LINK : https://drive.google.com/file/d/1szNCxDvxw5Pc51d6K7iD8aXOSJxhToM5/view?usp=sharing