MESHING IP SUBSTRATE FOR STRUCTURAL ANALYSIS USING ANSA

OBJECTIVE:-

• To clean up the topological errors present on the given model.
• To create mid surface for the given models by using manual method or the automatic mid surface creation method.
• Then the extracted mid surface should meet the following quality criteria.

ABOUT ANSA:-

It is a CAE tool for Finite Element Analysis and CFD Analysis and Widely used in the automotive industry.It maintains the association between the CAD Geometry and FE Mesh.This means the FE Meshes are better representation of the geometric parents.It is easy to maintain and update any changes in the geometry by simply reworking the updated area instead of recreating the FE Mesh from Scratch.It also carries several proprietary algorithm for meshing suitable for both CFD and Structural Models.It is used to do various activities like Topo , Mesh , VMesh , Deck , Solver , Morph and HBlock.

ABOUT INSTRUMENT PANNEL:-

It is one of the most important part of the car interior componentand plays important role in the different aspects such ass safety , reliability , user friendly , technology and appearence and so on.It is used for operating different functions in the car such as instrument panel , video devices , holders , switches and glove box these function distributed inside the vehicle that communicate with each other.It should absorb vibration when the car is at very high speed.

The materials used for Instrument Panel are Acrylonirite - butadiene - styrene (ABS) / Polycarbonate alloys , Polypropeylene , modified polyprophelene ether (PPE) and Styrene - maleic anhydride (SMA) resins. These Plastics allow for the complex designs in terms such as airbag housing , Center Stacks for the Instrument Panel and large intergrated instrument panel pieces.

It consists of air conditioning units , ducts , electronic units , harnesses and instrument panel is build around the steering member. The steering member is a part of the vehicle frame and it is the backbone of the cockpit module.It has many function such as providing strength and rigidity for the vehicle safety.Supporting components such as the air conditioning unit and connecting with the vehicle body.

TOOLS USED:-

1. TOPO - It automatically creates topological conditions between the selected adjacent coons.

2. Offset - It is used to create the new surface by offseting the selected surface for the entered distance.

3. Middle - It is used to create the mid surface by selecting the two faces.

4. Mid Surf - It is used to create the mid surface automatically by selecting the model.

5. Cons2Curves - It is used to project the coons into the curves.

6. Fill Hole - It is used to fill the hole.

PROCEDURE:-

1. First cleared all the topo errors present on the given models by using the manual method or the automatic fix method.For the 1 , 2 and 4 model there is no errors but the 3 and 5 model has some geometry errors like single coons , Triple Coons , Needle Face , Crack.

MODEL 1 MODEL 2

MODEL 3 MODEL 4

MODEL 5

2. Then Mid Surface is created by using the following methods three methods.

• Offset > Faces > then selected the faces need to get projected > then entered the offset value and then clicked ok and then selected ok to delete the original faces (or) select cancel not to delete the original faces.
• Middle > Single option to select the single face (or) Multiple option to select the multiple face > then select the two faces and then click ok to create the new faces inbetween the two selected faces.
• Mid Surface > Casting > then selected the model and then middle click and then selected the following parameters and then click ok.

FOLLOWING PARAMETERS

MODEL 1 BEFORE MID SURFACE EXTRACTION MODEL 1 AFTER MID SURFACE EXTRACTION

MODEL 2 BEFORE MID SURFACE EXTRACTON MODEL 2 AFTER MID SURFACE EXTRACTION

MODEL 3 BEFORE MID SURFACE EXTRACTION MODEL 3 AFTER MID SURFACE EXTRACTION

MODEL 4 BEFORE MID SURFACE EXTRACTION MODEL 4 AFTER MID SURFACE EXTRACTION

MODEL 5 BEFORE MID SURFACE EXTRACTION MODEL 5 AFTER MID SURFACE EXTRACTION

3. After mid surface extracted the mid surface is meshed for the target length of 5mm for manually created mid surfaced and for the automatically created mid surface it automatically meshed for the selected parameters.

After meshing the model for the above mentioned criteria the model faces some quality criteria issues in which the the 1581 elements gets affected by the following criteria

• • Aspect Ratio - It is the ration of longest to the shortest side in the cell.Ideally it should be equal to 1 to ensure best results.For multidimensional flow analysis it should be near to 1.Also the local variations in the cell size should be minimal and therefore the adjacent cell size should not vary more than 20%.Having a large aspect ratio error it can result in the interpolation error of the unacceptable magnitude.
  • Skewness - It determines how close to the ideal face or cell (i.e., whether it is equilateral or equiangular)
  • Warping - It is the amount by which an element deviates from being planar.since three points is used to define a plane so this checks is only applicable to quads.The quads is divided into two trias along its diagonal and then the aangle between the trias is meaasured.
  • Taper - It is defined by defining the area of the triangle formed at each corner of the grid point and then these areas are compared to one half of the area of the quadrilateral.
  • Minimum and Maximum Length - In our case the target length is given as 5mm and then the minimum and maximum length will be +/- 2 then the minimum length is 3mm and the maximum length is 7mm if the length goes beyong this then the error will get displayed.
  • Minimum angle - The qualifying criteria is the minimum angle in the surface elements and minimum dihedral angle for the volume elemets.This means the elements with a small angle are considered to be a worse quality than ones with a bigger angles.It is good for qualifying the triangles and tetrahedral mesh.
  • Maximum angle - It gives maximum angle for every elements.In this the elements with bigger angles are considered to be worse.It is good for qualifying the quadrilateral and hexahedral meshed elements.
  • Tria % - Percentage of the tria elements present in the mixed mesh.It is only for the visualization purposes.

All these errors are cleared by using the following tools

• Split - It is used to split the quadrilateral and triangular shell elements into smaller ones.It is performed between the selected nodes along the selected element edges.
• Swap - It is used to rotate the shell edge selected by the userinside the two shell so that it has the edge as common.
• Reconstruct - It is used to create a high quality of surface mesh.It automatically examines the selected mesh and performs remeshing to correct the problamatic areas and optimize the overall quality of the mesh according to the mesh parameters.
• MV Surf - It is used to move the selected node along the perimeter segement on which it lies.

MODEL 1 BEFORE QUALITY CRITERIA ERRORS MODEL 1 AFTER QUALITY CRITERIA ERRORS

MODEL 2 BEFORE QUALITY CRITERIA ERRORS MODEL 2 AFTER QUALITY CRITERIA ERRORS

MODEL 3 BEFORE QUALITY CRITERIA ERRORS MODEL 3 AFTER QUALITY CRITERIA ERRORS

MODEL 4 BEFORE QUALITY CRITERIA ERRORS MODEL 4 AFTER QUALITY CRITERIA ERRORS

MODEL 5 BEFORE QUALITY CRITERIA ERRORS MODEL 5 AFTER QUALITY CRITERIA ERRORS

CONCLUSION:-

All the topological error gets cleared and then performed mesh for the target length of 5mm and the created mesh had satisfied both the mesh parameters and the quality criteria.

Drive Link :- https://drive.google.com/drive/my-drive