Tool Test 1

TOOL TEST – 1

MID SURFACING AND MESHING OF SWITCH PANEL AND SHEET METAL COMPONENT

OBJECTIVE:

• In this tool test the main objective is to Pre-Process of 2 models
• Import the CAD geometry of switch panel and simultaneously sheet metal component
• Clean up the geometry until no topological error is found
• Extract Mid-Surface for the geometry

Mesh geometry with target/average length of 4mm

S.NO	QUALITY CRITERIA	VALUE
1	target/average length	4
2	Minimum length	2
3	Maximum length	6
4	Aspect	3
5	Warpage	15
6	Jacobian	0.7
7	Minimum Quad Angle	45
8	Maximum Quad Angle	135
9	Minimum Tria Angle	30
10	Maximum Tria Angle	120
11	Tria2 Percentage	15

ABSTRACT

• This tool test consists of 2 models 1) switch panel component 2) sheet metal component. One can use different methods for generating mid surface such as offsetting the parent geometry using feature area, generating skin for the whole geometry, using casting option to create mid surface, also by manual method which will take some time. In this tool test-1, I am going to explore all the options which are available to generate mid surface and mesh the components using the quality criteria mentioned in this report.

MODEL 1: Switch Panel Component

INTRODUCTION

• This component is situated on the door inside the interior of a car. It consists of different features like windows open/close buttons, handle to control the door, also some different buttons which are helpful to access different features.

Basic Switch Panel of Car

Bottom view of Switch panel

PROCEDURE

• Import the cad geometry and do geometry clean up with no topological errors.

Imported Switch Panel Geometry

• After importing the geometry into ANSA there will be many topological errors. In order to prevent this, we do a geometry clean-up which is in the check’s manager.

Checks Manager Dialog box

• The errors in the above figure can be fixed automatically using FIX option or if the errors are not rectified, we must clear them manually.

Checks Manager Dialog box

• After all the error are rectified,if you check the geometry the exceution will be 100% then you can move forward.

2.ASSIGN PROPERTY ID (PID)

• Every part in the geometry has it’s own property. We can assign PID using ANSA. We have to select the part and click Apply, then we have to select the whole part using window selection to apply the PID.Also assign different PIDs for different features for mid surface.

PID applied for parent Geometry

PID Assigned for different features of mid surface

3. MID SURFACE GENERATION

• Of all the options available for mid surface generation, I chose to do the mid surface manually for all the geometry.As this component consists of different features like ribs,teeth,zig zag structures, skin and casting options has not given me accurate mid surface.

Mid Surface of Parent Geometry Mid Surface generated at some features

Mid Surface generated at some features

MESHING AND IMPORVEMENT OF THE MESH

• Continue with meshing only after asigining the quality criterias and mesh parameters. I have mentioned them at the top which is same for both models.
• The quad elements are usually better than triangular elements. Similarly, parabolic elements are better than linear elements. For better merge transition we use tria elements at some places. It also provides good mesh flow.
• Trias at the edges and construction lines should be avoided for better mesh flow.
• We can recreate better mesh using reconstruction option which is in the shell mesh.

Meshing done for Mid surface

Meshing generated at some features

• As there are more triple cons of different features associated with same surfaces there will be some off elements in some areas. The length between each element will be less in these situations.

Triple cons nearer to each other

• In this project 1 element is converted into 2929 elements in total, 1)Quad elements: 2638 which is 90.96% 2)tria elements 291 which Is 9.94%. There are some off elements.

Meshing done for whole geometry

MODEL 2: Sheet Metal Component

• Import the cad geometry and do geometry clean up with no topological errors

Imported CAD geometry

• After importing the geometry into ANSA there will be many topological errors. In order to prevent this, we do a geometry clean-up which is in the check’s manager.

Checks Manager Dialog Box

• The errors in the above figure can be fixed automatically using FIX option or if the errors are not rectified, we must clear them manually.

Checks Manager Dialog Box

• After all the error are rectified,if you check the geometry the exceution will be 100% then you can move forward.

2.ASSIGN PROPERTY ID (PID)

• Every part in the geometry has it’s own property. We can assign PID using ANSA. We have to select the part and click Apply, then we have to select the whole part using window selection to apply the PID.Also assign different PIDs for different features for mid surface.

PID assigned for parent geometry

3.MID SURFACE GENERATION

• There are three ways in which one can extract mid surface for simpler components.

1)Using feature angle option

2) Using skin option

3)Using casting option

1)Using feature angle

• Using Feature area option we can offset the whole geometry by adjusting the angle.After selecting feature angle select the geometry and give offset value.

Offsetting using feature angle

2) Using skin

• Using skin option which is located under mid surface. With this feature we can select one region with red, one with green and the thickness with blue. Then skin will be generated automatically. But after generating the skin parent geometry will be automatically deleted.

Select one surface with red

Select one surface with green

Select thickness with blue

3)Using casting

• Using casting option, we can do both mid surface generation and mesh at the same time. This option is also located under mid surface. In this option one must give minimum thickness, element type, target length as it will generate mesh along with the mid surface.

Mid Surface generation using Casting

Mesh generated using casting option

• These are the 3 ways which we can generate mid surfaces for simple components like sheet metal.

Mesh generation at some areas

• In this project 1 element is converted into 10329 elements in total, 1)Quad elements: 9622 which is 93.16% 2)tria elements 707 which Is 6.84%. There are no off elements.

Meshing done for whole geometry

Learning Outcomes:

• Able to do topological clean-up with no errors.
• Assigned separate PIDs for different surfaces.
• Able to generate mid surface for complex geometry with varying thicknesses.
• Aware of all the quality criterias and quality parameters during mesh generation.
• Understood about mesh generation and implemented mesh generation for complex geometry.
• Learned how to improve mesh flow and remove trias to achieve better mesh flow.
• Understood all the concepts regarding mid surface generation in ansa.

Conclusion:

• From the above models i can conclude, method of generating mesh for any geometry is very similar in case of shell meshing. I followed all the procedure mentioned in the grading policy. Practiced all the command in ANSA. Generated mid surfaces using different options available in ANSA. Able to defeature and do line adujstments in some areas. Able to mesh them successfully without any off elements. The majority of elements must be kept near to target length.

Model of ANSA file link :

MODEL 1: https://drive.google.com/file/d/1TyurLRgdtRwA2H4aS3dp7goqNcQIHOKO/view?usp=sharing

MODEL 2: https://drive.google.com/file/d/1smp5O2QQsgMOZHn_cy7_kk4qwObzxYdh/view?usp=sharing