Week 8

Perform Morphing of a Given Component and Creating New Geometry

Objective

• IGES FILE to ANSA environment.
• Carrying out midsurface with any method manual or automatic.
• Assigning PID to middle surfaces.
• Performing a morphing and create new design with morphing.

Procedure

• Click on ANSA icon. It will ask you to choose the working directory and layout to work.
• You can use the performance mode for graphical issue.

Type (-performance_mode3) to get good results in below window

• Select ANSA and hit OK.
• Click on open and select the required file from ANSA environment.
• Go to opem file-à select the file hit open.

• It will appears as a shaded view in Entity mode. On left side it will shows the database.
• Database include some important tabs like properties and material.

You have to make the component fine to get actual view of cad geometry, and follow the topology

• When you fine all the areas you will get the exact idea about how the surface looks. As shown below.

• Now we have to clear the geometry issues spotted in the check geometry.
• Here if needed we have to set the PID according to the section.

• Now we are remaining with only surfaces which we are going to use for meshing.
• All analysis depends on a good meshing so we are going to mesh individual components.

1. Geomertry Cleanup

• Here we have separated the different surfaces according to the thickness of the component with different PID as shown in the picture below.
• Now click on the inner extract component. We have to check the component for the proper surface, which is free from any errors. Such as middle face, cracks, single, double, triple cons before taking mid surface.
• For checking the geometry, we have to go to the geometry checks manager to get error free surface.

• Removal of this errors in geometry lead to get the good and clear middle surface.
• We can remove errors individually or all together, it depends on the complexity of error.
• Errors can be removed manually or automatically. But manually fixing will give the better results.
• After removal of all the errors we will get a clear surface. Now we can go for the middle surface.

1. Defeature the Surfaces according to quality criteria

• Now defeature the lines which will affect the elements failure. According quality criteria ie min- max length defeature the lines of components.
• Now we have fully equivalence mid surface. We have to clean the surface to get clean and clear meshing. It will avoid the pinholes, very small edge and surface fillets automatically. We have to set the parameters according to requirement.
• Topo mode joins the surfaces together to get continue surface.
• Removing the unwanted lines we get the surface which is required for meshing.
• Set the property id for extracted mid surface. Property may define the thickness of the shell elements.

1. Extraction of Middle Surface
2. Now for creating the middle surface we have to measure the distance i.e. thickness of the component as given below.

• Go to utilities à Measure à click the two hot points to measure the thickness of the concerned component.

• Creating of midsurface with offset distance. As shown in pic

• Now we have fully equivalence mid surface. We have to clean the mid-surface to get clean and clear meshing. It will avoid the pinholes, very small edge and surface fillets automatically. We have to set the parameters according to requirement.
• We will get number of offsetted surface we have to follow the topo mode. Topo mode joins the surfaces together to get continue midsurface.
• We also use the middle option in faces tab to get the middle surface where offsetting is not possible.

• Set the property id for extracted mid surface. Property may define the thickness of the shell elements.

1. Setting up parameters and quality criteria

• Set the required mesh size, type of mesh and order of meshing required,according to customer requirements and accuracy required.

Eg. Target Element Size= 1mm as shown in picture.

• Now click on edit criteria. This is where we have to specify the criteria for the Quality index of meshing.
• Set all the quality criteria and save the details as a file.

• These are the criteria on which our meshing gets checked on quality of meshing.

E.g. Min/ Max Size of element, Aspect ratio, Warpage, Min/Max Quad angle, Skewness etc

1. Meshing

• After geometric cleanup and setting the conditions now we are going for meshing.
• We have to finalize the target mesh size and set the perimeter length. Setting of the perimeter length for meshing divides the surfaces into the imaginarily small parts for required meshing.
• Select the surface as displayed surface. Choose element size as per requirement. Here it is
• Use mesh type as Mixed. And hit the mesh button on screen.
• Adjust the nodes according to requirements. Make sure the mesh flow is good. Adjust each area of meshing with care to get a quality mesh. Hit middle mouse button to exit the mesh.

• Mesh flow near cutouts and at edge will specify mesh quality. Now meshing is done. It’s time to check the quality of the mesh.

1. Quality Check

• Click on quality index. It will show the no. of elements failing in quality criteria which we have specified previously. The quality of elements are only seen in the hidden mode. Change the mode to hidden and check the quality of elements.

• So the quality index will show the failing elements or worst elements in the meshing. We have to avoid these elements during meshing. We can overcome these elements by remeshing certain areas again which is a good way to do it.
• Click on F11 and select the elements. Select the element from the outer edge to reconstruct the surface.

• Make a square to remeshing. It will easy to reconstruct targeted area. This is way to get remesh all the surface again and again. Repeating this procedure you will refine mesh.
• Now again we can check for the quality criteria. In quality index we can use the tools like place node, node optimize, element optimize, split option, paste, split quad, combine tria etc
• These tools also help to get rid off from bad mesh.
• Place Node use to place a node at a required position. We can use element optimize to adjust the element as per meshing thresholds specified earlier. These options will adjust the element at minor level..
• Split and combine tria are also used for removing tria from mesh or adding together to form a quad element.
• Apart from these entire tools smooth tool is used for very minor adjustments in the elements to complete quality criteria.
• After doing all this you will get a quality mesh which will pass all the quality criteria. In industry point of view the tolerance is given for quality criteria’s it may be in 5% to 10%.

CREATE MORPH BOXES

• The component appears in auto mode and mesh view.
• Now click on Morph tab on upper right corner.

• Click Boxes and create new Morph box. Select the target elements.
• Create morph box.

CHANGE THE PARAMETERS

• You can split the morph box according to requirement. Control points help is changing the shape of model accordingly.
• It will help you to move the volume morph with respect to control points.

Morphing

• Now we are going for morphing
• Select the control points to move for required shape. As the control points have all the degrees of freedom. This will allow the volume morph to move the elements accordingly.
• You can also create freehand where you can choose moving nodes, fixed nodes and elements affected.
• This will also used for morphing here

CONCLUSION:  

1. Morph allows us to make optimum changes in meshing without disturbing mesh flow
2. Alter dimensions in mesh itself is possible with morphing.
3. We can create the domains according to type of elements which we can use again for different types of morphing.
4. We also use 3d-solid map-line drag option to get morphing surface according to the required line.
5. Morphing is used to get the optimum results without changing the entire meshing procedures, which will save the time and cost of work.
6. The morphing is widely used in Automotive industry, aviation industry, computer and animation graphics industry.