MESHING A CYLINDER USING ANSA

INTRODUCTION : ANSA is a computer aided engineering tool for Finite Element Analysis and CFD analysis widely used in the automotive industry. It is developed by BETA CAE Systems.

ANSA maintains the association between CAD geometry and the FE mesh. ANSA stands for \'Automatic net generation for structural analysis\'.

ANSA phases : import cad geometry -> geometry clean up -> skin or mid surface generation -> shell or solid meshing -> element quality check -> mesh improvement -> apply load -> export.

OBJECTIVE : To mesh the give cylinder model by using element size as 1 units by using ANSA.

Meshing : A mesh is a representation of a larger geometric domain by smaller discrete cells.By meshing you break the domain into pieces and each piece represent an element.

meshing process : define element size -> choose size of element -> selecting type of mesh to done -> quality criteria check -> remesh for quality improvement if needed.

PROCEDURE :

Tools Used : shadow,Measure,property,checks,set PID ,not,all,invert,length,spot mesh.

OPEN THE MODEL : First of all the model in ANSA then if the shadow mode is off you see the below model .

Then turn on the shadow you see the below model.

then go to pid mode to do further operations . so, as by giving the PID we can differentiate the inlet outlet with differnt colours

then you observe that there are cons but they are of same. so then go to quality criteria -> presentation parameters -> visualization

the under it switch on the draw cons in PID,MID .. and keep the detail on demand effect to low and apply and press ok .

then you are able to see cons of different colour

Geometry checks : This is done to check whether there are any holes or any geometry disorder.

To do this operation go to checks -> geometry then execute . then if there are no errors it shows a window with no error or warning exist .

If no error exist then assign PID.

Assigning the PID : It means to assign the properties like inlet,outlet,and wall for a cylinder.

To assign PID first select set PID under faces -> then select any face for now we select inlet -> click middle mouse we get properties.

To create new a new PID for it then select new create a new one and assign a name and double click on it assign.

Similarly create pid for remaining.

Assigning colour to created PID .

Select near colour box beside name and double click to get colours window and then select a colour and press ok.

You can apply PID directly by double click or right click con colour and then select apply .

Then create the PID for other in the same way.

Then after creating PID you can see them in the properties ( CTRL+ P). You can see the PID on model by click on the required PID in the menu.

After giving PID we have to mesh the model.

MESHING THE MODEL : First of all you have to go to mesh mode . which is on the top to be selected.

Then we have to give mesh length by selecting the length under parameters and then select the whole model by drag and drop then click middle mouse. and give the mesh length as of required at present we give mesh length 1.

After giving the mesh length you can see the change in the model .by giving less mesh length we can get the approximate exact value on doing analysis.

You can check mesh length by selecting the Measure and selecting two nodes you can see the length in between them.

Then finally you have to mesh the model.At present we use spot mesh.

To do spot mesh we have to select spot mesh under mesh generation then select the whole model. before clicking middle mouse we have to check the option list at the bottom.

As of now we need tria elements we have select it and reconstruct to be enabled.

Now after selecting this press the middle mouse button or under spot mesh visible to do the mesh.

Now after the meshed model is seen then do the mesh check so that any mesh errors can be checked .if no errors you will see the below window in ANSA.

Then the final mesh model is to be saved.

LEARNING OUTCOME : In this process we have learned how to rectify geometry errors and mesh a cylinderical model and how to rectify errors in mesh and how those errors to be corrected.

CONCLUSION : Here finally we have meshed the given cylinderical model . You can also see the number of elements meshed in the model at the left side of the workbench.

AS we have selected on tria elements we see quad elements are 0 . Here you can see there are 604978 tria elements in the cylinderical model we meshed .