Learning Forum

[per.pucher]

Hi everyone,

I want to evaluate the different modes and mode shapes in a structure (approximate size 1m x 1m x 1m) designed to accurately position micro-mechanical parts (± 200 nm). The machine produces vibrations in the ultrasonic range (around 40 kHz). I need to know whether this excitation can affect the accuracy of the structure.

Are there specific things I need to watch out for (like types of mesh or mesh size) in order to achieve accurate results at high freuqencies? Do I have to choose an element size which is at least 2 times smaller than the wave length of the 40 kHz ultrasonic wave?

Thanks in advance for your help.

[Erik Kostson]

 

Hi

In general the guideline would be to have about 6 elements (quadratic so say solid186) per wavelength.

See the course in modal analysis for more info on how to set it all up.

Thank you

Erik