Modelling of a Dashboard (Instrument) Panel of a car using ANSA
Aim
The aim of this project is to mesh the given Instrument panel that follows the given mesh parameters and also the specified quality criteria
Procedure
Before we begin with the geometry cleanup, we first refine the model as the model does not look well defined when imported into ANSA. This hinders with our visualisation of the model as the edges look distorted and not properly stitched together. To do this, we proceed to the mesh module and set the length as 1 for perimeter and macros from the default length of 20.
After refining the model looks much clearer and well defined.
This can be observed by the differences between the two images shown above. The second one looks much sharper and clear. This is followed by performing a topo(logy) which stitches the cons together.
The single(red) cons turn to double(yellow) cons and in some regions two yellow cons are accidentally stitched together by ANSA as they are too close to each other thereby making it difficult for ANSA to identify as two different lines.
This is the reason for performing a geometry cleanup as the geometry should be error-free before we start with meshing.
Checks--> Geometry
As we can see, the checks manager shows us more than 500 errors which include Unchecked faces, Triple cons, Needle faces and Crack between cons. These errors can be fixed automatically or manually. Since the number is high, we go with the auto-fix first which reduces the number of error significantly followed by manually cleaning the remaining errors. When all the errors are cleared, we get a green tick mark which denotes that the geometry is clean. We should orient the model to one uniform colour grey/ yellow using the Orient option.
We proceed to the next phase which is the mid surfacing part. For mid surfacing/mid-planing, there are different methods ranging from the auto mid surfacing methods such as casting and skinning to manual mid surfacing method like offset. There are limitations to each method. The skin method takes out the mid surface but deletes the parent geometry but we'll require the parent surface for reference. The casting method takes the mid surface and also meshes the mid surface. The mesh quality and flow might not be good.
Therefore, we go with manual mid surfacing method called offset. Although time consuming, we have precision and reliability as all the mid-planing is performed by us. We select the features option as majority of the model hasa thickness of 0.6mm. We offset it to 0.3mm which is at the middle.
Other regions are offset individually by measuring their thickness. Also Middle-->Single is used for symmetric, uniform thickness areas. Although there are many features, there are less complex and easily offset. But some features like the one shown in the picture shown below need to approached in a different manner.
These are solid cylindrical features attached with ribs to their sides. To capture this in 2D meshing and not a volume mesh, we use the curves to create a rectangular feature which when provided with the thickness for the property as the diameter length generates a cuboidal shape that is approximated as a cylinder.
We can see that these curves are created using cons2curve, curves middle and also create curves to achieve this.
This is how the mid-surface looks along with the curves generated earlier. The diameter is assigned as the thickness. As we mid-surface, component by component their thickness are assigned to them in different PIDs.
We can observe that the thicknesses are different and so are the colour pattern to distinguish between them when viewed in PID mode. With this, we have completed the mid-surfacing of the entire component.
We move to meshing the component. First, we set the given quality criteria.
And second, we set the mesh parameters where the target length is set as 4mm. Also, the perimeters and macros have been changed to 4 from the initial value of 1 set for refining purposes. We go for the best mesh scenario which uses a combination of all the known meshing algorithm to mesh the component. We also reconstruct the mesh in required areas so that rotating quads, back-to-back trias, trias on the free edges are avoided and a good mesh flow is obtained.
Fillet regions sometimes fail the quality criteria. Therefore, we use dach divide option to divide the fillet in the middle and remove the edges thereby eliminating the failing region.
We can observe that the fillet is represented by a single line instead of two lines and this is achieved by using the dach divide option. We completely mesh the component.
This is the meshed component without applying the thickness. Now we apply the thickness option present in Presentation parameters -->Draw shell as solid.
We can observe that the thickness has been assigned and the cylindrical features represented as rectangular ones have also been shown above. With this, we have successfully meshed the component completely.
Link to the model
https://drive.google.com/file/d/1RE9-nnxyl4eRkXc-tzgqVCRoQaOHdLPI/view?usp=sharing
Learning outcomes
This project has given us how the meshing in the automobile industries is performed. It is a huge component and meshing this takes time and accuracy. Working on this kind of components gives us an oversight into how it should be done on a large scale(say, in an industry).
Conclusion
We can conclude by saying that meshing in the intricate areas require patience, precision and meshing in larger areas require the knowledge to mesh the component. We have also gained a wide knowledge of meshing large scale components with the help of this model