Project 1 - Meshing of Floor Panel
Project 1 - Meshing of Floor Panel
Follow the below-mentioned quality criteria, mesh the component given below, and assign thickness:
Target Element Length = 5 Units
S.N Quality Criteria Value
1 Aspect Ratio 5
2 Skewness 45
3 Warping 15
4 Taper 0.5
5 Min. Length 2 Units
6 Max. Length 8 Units
7 Min angle Quad 45
8 Max angle Quad 135
9 Min angle Tria 20
10 Max angle Tria 120
10 Tria % 10
The floorpan is a large sheet metal stamping that often incorporates several smaller welded stampings to form the floor of a large vehicle and the position of its external and structural panels.
Steps involved in ANSA
- Import the geometry
- Geometry clean up:
To ensure that all the surfaces are connected properly Faces>Topo tool is used for all the edges of each individual component at a time. Next, a geometry check is performed by going to Checks>Geometry and running it for parameters as shown in the image below. Initial 201 errors were found. Auto fix option could able to fix, most except 12 errors.
The below figure shows some of the error.
After clearing all the errors.
The next, step is to extract the mid surfaces for each component and keep them in separate property ID. Midsurfaces are extracted using the manual method i.e. offsetting the surfaces of either face to the middle. Or by midsurface → skin option. First, the thickness of each component is measured using the Measure tool from Utilities>Measure. The thickness is uniform hence the component is sheet metal . Next, the mid surface is extracted using the Offset tool by going to Faces>Offset and selecting all the surfaces on one face. Then, half of the thickness is given as the offset value, the direction is checked and offset. Now, the property is assigned to the extracted mid surface by going to Faces>Set PID and assigning to the respective property.
Prepare the mid surfaces for meshing. For that, switch to the Mesh module. First, the shell element length is altered by going to Perimeters>Length and all the CONS are selected and target element length 5 is fed as length value. The same is done for all the Macros (surfaces).
Quality criteria are configured by going to Utilities>Quality Criteria. And, the quality criteria file is saved for future reference. The created quality criteria parameters are shown in the image below.
mesh parameters are configured by going to Utilities>Mesh Parameters. There, target length, minimum element length, and maximum element length are configured
meshing is done using the Mesh generation>Best tool. This tool generates the mesh using the best algorithm applicable. Then, the created mesh is refined using the Shell Mesh>Reconstruct tool. It is ensured that there are no rotating quads. Also, trias are kept as low as possible.
Mesh quality is important and mesh flow. Mesh qlaity and mesh flow is obtained by the following options.
Grid>Paste, to paste the nodes and move tria backward
Elements>Split, to split an element and move tria forward
Elements>Swap, to move the tria left or right
Elements>Join, to join two trias to make a quad
After modifying the mesh, Shell Mesh>Smooth tool is used to smoothen the flow of the mesh. Any elements failing for quality criteria are also fixed by either remeshing or smoothing the elements. The created mesh is shown below,
Challnges in the project:
In the previous challenges the error are of triple line, single cons and needle faces. In this challenge missing/distorted surfaces, intersecting surfaces, etc. were more.
Feature were more as it is sheetmetal component, feature is important as well quality of the mesh. Most of the mesh were failing for minimum length which needs a compromise between the quality and the feature.
LEARNING OUTCOMES
- Learned to work on floor panel from mid-surfacing object as the panel had many feature.
- Learning on improving mesh flow since mesh flow is something that cannot be absolutely perfect in components such as this.
- Learnt to check all the areas for minimum element length and to alter where elements might fail for minimum length. Similarly, CONS which are not essential to define a feature are removed by joining the surfaces
Conclusion:
Importing the geometry , geometry cleanup, mid surface extraction, and 2D meshing of the given hood model were successfully done. All the features in the model are captured properly with good mesh flow.