IP SUBSTRATE STRUCTURAL ANALYSIS || ANSA

OBJECTIVE:

• To take the mid surface of complex geometry of instrument panel substrate.
• Mesh the mid planes.
• Incrrease the quality of each element by the quality criteria assigned.

IP SUBSTRATE:

The instrument panel or ip is a control panel located in front of the driver in a vehicle. It displays instruments and controls for the vehicle which include all the gauges speedometer, fuel gauges, gear shifts, music system.

The ip substrate is the thinnest component and is made by injection molding. It's thickness is not uniform because it is a plastic component which is molded. The material which is used is polypropylene glass filled.

Fig 1 - Ip substrate

MODEL 1:

Fig 2 - Model1

Fig 3 - Model 2

Fig 4 - Model 3

Fig 5 - Model 4

Fig 6 - Model 5

Geometry Cleanup:

The errors were taken care by using various option such as:

Release cons: Disconnects the cons from the surface.

Topo: Creates topo conditions between selected cons.

Universal delete: Deleted selected entities of any type.

New faces: To create new faces by selecting the cons

Project (hot points): Projects hot point as needed to the different con.

Insert (hot point): Used to insert hot points in the cons wherever needed.

Intersect: Allows to intersect the two surfaces which is selected.

Cut faces: It requires two hot points to make the cut within the surface.

Project cut: To make a cut from one hot point to the other con.

MID SURFACE EXTRACTION:

Manual mid surface extraction can be done using the offset faces, middle (single or multi).

The offset function helps us to extract the midsurface by selecting each faces. The offset distance has to be entered for the mid surface which will get created depending on the direction.

Fig 7 - Mid surface extraction manually by offset function

For extracting mid using middle multi we need to have identical faces. It requires to select the first area which is highlighged in red, then on selecting the second area it is highlightes in green. Then the mid part is placed in between the surfaces.

Fig 8 - Mid surface using middle multi

Using the above functions the mid has been taken manually for model 1 and has been shown below.

Fig 9 - Mid surface taken for model 1

To take the mid surafce manually for the rib structure using the offset, extend & cut operation.

Fig 10 - mid for the ribs

Manual mid surface extraction takes time but mid suraface can be extracted automatically with the help of mid suface casting operation. This operation gives a mid surface FE directly.

Fig 11 - Mid surface extraction by using mid surface casting and thickness allotment

For the automatic mid surface extraction the geometry should be free from errors.
The advantage is that it is a very useful operation as it saves two-third of the time. It is useful for taking out the mid surface for complex geometries.
The only disadvantage is that the result given is not precise the user has to make some alteration as in some of the areas the mesh may be distorted and the elements may not be aligned properly.

Ansa is also capable to assign the thickness as shown in figure 11 right end column by using the calculate middle surface thickness.

Fig 12 - Dialogue box

This is the dialogue box for calculate the thickness with the help of ansa. The option chosen is to create PIDs with the step size of every 0.5 mm variations.

Likewise the mid has been taken for the rest of the model which has been shown below. The meshed elements has been corrected using the align, delete, fill & new operations.

Fig 13 - Mid surface FE of model 2

Fig 14 - Mid surface FE of model 3

Fig 15 - Mid surface FE of model 4

Fig 16 - Mid surface FE of model 5

For the above mid surface extraction using the mid surface casting option it was made sure that the geometry is free from errors. There were some errors in some of the models and the errors were eliminated before extracting the mid.

The quality criteria which has to be followed:

Fig 17 - Quality Criteria

Assigning the above quality criteria in the quality criteria presentation parameters.

Fig 18 - Presentation Parameters Dialogue Box

Tools used for correction of the elements in the mesh:

• RECONSTRUCT:Reconstructing the surface mesh by using the reconstruct funtion enabling the remesh macros target length was chosen to be average it enhances the quality of the surface mesh.
• MV SURF: It helps to move the point along to the node on which is lying.
• SMOOTH: The original version of the mesh is smoothed.