Hi Experts 

I was making an assembly to do the stress analysis in . Just wanted to know a little bit deep about defining contacts.

At the moment, the contacts has been defined by using "automatic contacts". But the way assembly has been constrained has got 42 interferences and I expect some gap between some of the components (less than 1 mm because that's how it is welded).

So, what I am looking for is some guidance regarding 

1. What are the thump rules for defining contacts ?

2. What are the thump rules to be followed while modelling for best results ?

3. What issues will arise in my 42 interference story above and what is the reason for that (from FEM point of view) ?

Thanks

Basil