variable thickness or modulus modeling 3

[cspkumar]

Hi all,

I am trying to model a circular membrane (thin film) with a variable thickness coating in Algor (thickness increases from zero at the center to a finite height at the edge). The way I have been modeling the variable thickness distribution is by having many elements to approximate the
continuous change.

Since there are many guys here who have a lot of experience with finite element modeling, I am asking if there is an approach to model either the continuous change in thickness (by keeping modulus constant) or modulus (by keeping thickness constant)?

Thanks

 

[corus]

Modifying the modulus will only be of benefit if you know that the stress will only be due a bending stress or a membrane stress. If it's both then you can't do it as the stress in bending is proportional to the thickness squared, whereas if it's membrane then it's proportional to the thickness. A combination of the two can't be approximated by some single proportionality to the thickness.

corus

 

[cspkumar]

Since the model in question is a membrane or a thin film where membrane stresses are predominant than the bending stresses, I think it's quite reasonable to model varying modulus instead of varying thickness.