suggestions for FEA validation

Hello all,

I want to make some design changes to a bracket attached to an IC engine and
I want to make sure I end up with a part as robust as the one it is
replacing. Tooling is expensive so I would like to validate the bracket
using FEA techniques before actually ordering parts. I have vibration data
(PSD) from the old design but I'm not sure how to put it to good use. Should
I just concentrate on making sure the stiffness/ resonance is comparable
between the two designs or am I missing a better approach?

Thanks!
Mel

 

Dear Mel,

For this type of thing do a comparative analysis. Carry out an analysis of
the current component, then do the same for the replacement. You should not
be interested in the absolute stress levels, but in the difference in stress
between the two designs. Pro/Mechanica has the ability to do a 'Dynamic
Random' analysis, which is what your vibration data can be used for input.
Remember that if your PSD is in 'g' to multiply by the acceleration due to
gravity is in the units system that you are using (e.g. 9810 for mm). You
will need to apply the PSD in the specified direction, or if you don't know
it, in X Y & Z. You should be able to compare the current and revised design
without worrying about the absolute values of stress.

Regards,

Rod Giles
Pro/Mechanica Users Group UK