[Libmesh-devel] more linear elasticity

[David K. <dkn...@se...>]

I was at a COMSOL junket today, and they said they have a cool feature 
that allows you to enforce constraints. Then they showed a constraint 
example of a uniformly loaded 2D cantilever, where you want to figure 
out what upward force is required on the free boundary of the cantilever 
to obtain zero vertical displacement there.

This is just a small change wrt systems_of_equations_ex4, we just need 
to add a Lagrange multiplier (SCALAR). So I figured I'd implement it 
(see attached). Should I check it in? (Tell me if I'm going overboard 
with the examples... it's a bit addictive though hehe)

David