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Mesh Question

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0702518

Mechanical
Sep 24, 2012
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Hi,
Looking for some advice or clarification that I understand how Mechanica works with respect to meshing.I have created a simple test part shown below and gone through many of the mesh settings to understand the influence they have.

My question is, is the default mesh shown below on the left sufficient?
I understand Mechanica uses the p-element method which means a mesh can be coarse and results are obtained by increasing the order of equations until convergence is achieved, so I think this mesh is OK?

I am working with some people who used to different programs and they desire that I create a more uniform mesh - kind of like I have created in the bottom right picture by limiting the max element size. But is this approach good practice with mechanica? I guess it would significantly increase the analysis time?

If anyone can give some advice and let me know if I am understanding this correctly it would be much appreciated.


Capture1_lefcfw.png
Capture2_iugbkx.png

Update:
I performed an unconstrained modal analysis on both and compared the results - see bottom pic. I see there is a lower convergence % for the more uniform mesh - is this more desirable?
delta_vvip2z.png

Thanks
 
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Simulate has two options to solve the analysis:

1. Single Pass: For single pass, the solver actually runs two passes to achieve convergence. In either pass, the mesh remains same, but, the order of the polynomials increases in the second pass at regions where the errors are higher.

2. Multi-pass: With this setting, the solver runs multiple passes until the solution converges to the set criteria. Note that in this setting, just like in the single pass, the mesh is the same throughout all passes, but the element polynomial orders increase at regions where convergence is hard to achieve.

Note that in either setting, you want to "exclude" regions which are known singularities or regions that are difficult to converge. These include locations where pointed loads, displacement constraints, weighted links etc exist.

For linear analyses in Creo, I use single pass approach with some mesh refinement in the region of interest. Typically, the elements are much bigger than the quadratic elements I use in Abaqus or any other H element solver.
 
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