2D Meshing on plastic component using ANSA

For The Given Component, Check The Geometrical Error Meshing With The Give Element Quality Criteria. After Meshing The Component The Thickness Has To Be Assigned .Write A Detailed Report On Your Process And Also Mention Which Method You Used To Extract The Mid-Surface Along With The Reason.

Sr.No.	Quality Criteria	Value
1.	Target/Average Length	1
2.	Minimum Length	0.5
3.	Maximum Length	3
4.	Aspect Ratio	3
5.	Warping	15
6.	Skewness	45
7.	Jacobian	0.7
8.	Minimum Quad Angle	45
9.	Maximum Quad Angle	135
10.	Minimum Target Angle	30
11.	Maximum Target Angle	120
12.	Tria Percentage	15

Solution:

Aim:

To Check The Geometrical Error Meshing With The Give Element Quality Criteria. After Meshing The Component The Thickness Has To Be Assigned.

Steps Involves In This Challenge

• Geometry Clean-Up.
• Mid Surface Extraction, Set Property Id And Quality Assigning.
• Meshing And Assigning Thickness To It.

1. Geometry Clean Up; Before Opening The File We Have To Set The Tolerances And Resolution From The Settings Options, These Options Ensure That The Topology Is Performance For The Specified Range During File Opening.

The File Is Of .Stp Format And Now The Component Is Ready For Geometry Clean Up And For That, We Have To Check The Geometry Errors Found Out Is Shown;

Fig 1; Geometry Check

There Are Gaps Present Between The Two Cons And Unwanted Needle Faces Are Present In Between Two Faces. By Using Topo Module Button The Actions Are Performed To Fix The Errors In The Geometry.

From Face Module Used –Delete, New, Topo

From Cons Module Used –Release, Paste

So ,With The Above Tool, We Have Done The Geometry Clean Up.

Fig 2; Geometry Clean Up Has Done

2.Mid Surface Extraction: The Mid Surface Of The Bottle Cap Is Taken By A Manual Method Using The Offset From The Face Module And Middle From The Curve.

Offset: Help To Extract The New Surface At A Certain Distance From The Select Face

Mid Surface: Helps To Extract The New Surface Exact Middle Of The Selected To Opposite Faces

Fig 3; Mid Surface Extraction From The Bottle Cap

Property Id Assigning;

Here We Having A Separate Property Id And Similarly We Should Create A New Property Id For The Mid Surface And Details Like Thickness And Other Material Properties To Be Mentioned

Fig 3; Property Id Assigning For Tope Surface

Fig 4 ; Property Id Assigned For All Surfaces

Quality Criteria: Before Starting With Meshing The Model, The Mesh Parameters Have To Set.

Fig 5; Quality Criteria

There Are Two Types Of Two-Dimensional Cell Shapes That Are Commonly Used. These Are Triangle (Trias ) And Quadrilateral (Quad ):

Aspect Ratio:

The Aspect Ratio Is The Ratio Of Maximum Edge Length To The Minimum Edge Length Of Element .The Ideal Value Of The Aspect Ratio Is 1.That Means All Sides Of An Element Are Of Equal Length. If The Aspect Ratio Is Greater Than 5, Its Means That The Max Length Is 5 Times Greater Than Min. Length Of The Element Is Said To Be Failed In Aspect Ratio Criteria. However An Aspect Ratio Of Less Than 5 Is Generally Accepted.

Fig 6; Aspect Ratio

Skewness:

• Skew In Trias Is Calculated By Finding The Minimum Angle Between The Vector From Each Node To The Opposing Mid-Side And The Vector Between Two Adjacent Mid Sides Of Each Node Of The Element. Ninety Degree Minus The Minimum Angle Found Is Reported.
• Skew In Quad Is Calculated By Finding The Minimum Angle Between Two Lines Joining Opposite Mid-Surface Of The Element. Ninety Degree Mines The Minimum Angle Found Is Reported.

Fig 7 ;Skewness

Warping: It Is Defined As The Angle Between The Normal Two Planes Formed By Splitting The Quad Elements Along The Diagonals. The Maximum Angle Of The Two Possible Angle Is Reported As The Warp Angle.

Fig 8; Warping

Jacobian:

The Jacobian Is A Scale Factor Arising Because Of Transformation Of Coordinates System. Elements Are Transformed From The Global Coordinates To Local Coordinates (Defined At The Centroid Of Every Element)

Minimum And Maximum Length:

Here The Average Element Length Is Taken As 3mm And Min Length Has 0.5mm And Maximum Length As 3mm.

Minimum And Maximum Angle Of Quad And Trias:

Similarly To Length Of Element Angle Between The Edge Of The Quad And Trias Is Also Taken Under The Quality Criteria.

Triangle %:

Since It Is Mixed Elements Considered For The Meshing So We Taking A Percentage Of Trias To Be Present In The Meshing.

1. Meshing And Assigning Thickness To It:

Here The Quality Condition Provided In Challenge Is Entered Into The Quality Criteria And It Is Saved For The Checking While Meshing. Here The Best Meshing Algorithm Is Used And The Element Type Is Taken As A Mixed Type And Used The 1^st Order Equation For Solving.

Best Mesh Generation In Well-Organised Algorithm Form Achieve If The Macro Area Is Properly Defined Say In The Rectangular Shape, It Also Reduces The Human Efforts, And Features Are Also Most Perfectly Captured.

Fig 9; Meshing Is Done On Bottle Cap

To Eliminate The Quality Criteria Errors:

• When The Meshing Is Done On Complex Area Like Feature, We Need To Do Some Reconstruction And Smooth Function Is Properly Align The Element And To Best Quality Meshing Which Should Be Remove The Quality Issues
• If The Area Is Too Big We Can Be Able To Divide It Into Small Areas Lets, Say The Macro Area And Can Be Able To Do The Best Meshing Out Of It.
• Moreover, The Options From The Module Like Past, Split Swap, Cut Join Are Used In Order To Do Meshing Properly.

Now We Need To Check Whether We Defined The Thickness Properly Into The Property So The Quality Criteria When The Shell To Solid To Select And We Can See The Thickness Got For The Mid Surface

Fig 10;Assigned The Thickness To Mid Surface Of Bottle Cap

Learning Outcomes:

• Fixed The Geometrical Errors In Ansa By Manually.
• Learn To Extract The Mid Surface For The Component.
• To Assigning The Property And Material Specification To The Component.
• Studied To Do Meshing According To Quality Criteria.
• Used The Transformation Option To Do Meshing Effectively And Saved Much Time.

Conclusion:

The Mid Surface Is Extracted Properly And Meshing Is Done With Proper Quality Criteria.

Meshed Bottle Cap Model Link Provided Below:

Https://Drive.Google.Com/File/D/1y46uxm7etd3znyferzh_Um4zuf1pvsbr/View?Usp=Drivesdk