Analysis of Hood using the advanced Pre-Processing Beta CAE ANSA

Analysis of Hood using the advanced Pre-Processing Beta CAE ANSA:

OBJECTIVE :

Import and clean up the model,extract the mid-surface by assigning the thickness ,set the quality criteria according to the given data for the model.

Quality criteria :

PROCEDURE :

The following steps to be followed to fullfill the objective ,

1. Clean up the model

2. Extract the Mid-surface

3. Assigning the Quality criteria

4. Meshing the model with appropriate element size with the given quality criteria

1. Clean up the model :

The CAD model is seleacted and imported from the desired derive to the ANSA for the Pre-Processing.In this process first we have to select the cross hatches option and it draw a diagonal line in each faces and the intersection of these lines make a point.2D shell mesh is used to this model for meshing.

In this process we have to check whether the process is error free.In order to that we have to select the check manager option in top menu and select geomentry.Depending upon the simulation process the cons and faces may vary but in this model will select the default selected option andexecute.Finally it display the status of the model is ok for futher process.In this model we have inner and outer panel.Use the iNot option to seperate the inner and outer panel and store in the face option.Next step is mid-surface since the structural analysis was done on midsurface of the panel.

CAD MODEL

INNER PANEL OUTER PANEL

GEOMENTRY CLEANUP

2. Extract the Mid-surface :

In this process we have to extract the mid-surface from the model using,the given geomentry has a uniform thickness of 0.75mm and the inner pannel of the hood is offset by -0.75/2mm.The negative value is give to offset the geomentry if oppposite direction.

TOPO>FACES>MID-SURFACE>SKIN

MID-SURFACE WIREFRAME MID-SURFACE

HINGE AND LATCH OUTER PANEL

Next step to check the given geomentry is symmetry,this ensures whether the model is same on both the side to offset and this makes the meshing process simple. we can do mesh at one side and i can be transformed to another side its safes time.the green and blue colour shows the symmetry surface on the model.

TOPO>FACES>RMDBL>GEOMENTRY

RMDBL SYMMETRY

3. Assigning the Quality criteria :

Quality criteria for the mesh parametrs were assigned and checked,

QUALITY CRITERIA

In the final step the surface has to be meshed as per the quality criteria and the average size of the mesh element is 5mm and the minimum and maximum length is 3mm and 7mm.Once the surface is done there will be a error and the some element will not follow thw quality criteria and those element to be corrected .when we move to mesh mode there won't be any cross hatches visibility.In mesh mode we have only nodes and edges.

MESH ERRORS

To solve those errors we have follow some command,

MESH>HOTPOINTS>INSERT & DELETE

MESH>PERIMETER>NUM+/-

MESH>SHELLMESH>RECONSTRUCT

MESH>ELEMENTS>SWAP

MESH>ELEMENTS>SPLIT

MESH>GRID>MOVE>SURFACE

MESH>GRID>PASTE

The final mesh is done,

MESH INNERPANEL MESH OUTERPANEL

FINAL HOOD MESH

4.Conclusion:

We have cleaned the geomentry for the given model,extract the midsurface with the assigning thickness and the geomentry was meshed using the perimeter lengths and the given quaity criteria was followed to have a smooth surface mesh.