Rod Shape Function
Rod Shape Function
(OP)
Good evening all,
A very simple question, might seems obvious but I'm started to get confused...
When dealing with bar, the usual shape function is a linear one: N(x)=ax+b
However, I wonder why don't we choose a degree 2 shape function after all? The exact solution of the displacement is polynomial (degree 2)
Perhaps, it's because we assume that strain=du/dx=constant, in the small displacements assumption?
In that case that would justify the linear interpolation of the displacement.
So I'm still a bit in the dark, and I cannot find any answer to that question!
Thanks for your help
Tom
A very simple question, might seems obvious but I'm started to get confused...
When dealing with bar, the usual shape function is a linear one: N(x)=ax+b
However, I wonder why don't we choose a degree 2 shape function after all? The exact solution of the displacement is polynomial (degree 2)
Perhaps, it's because we assume that strain=du/dx=constant, in the small displacements assumption?
In that case that would justify the linear interpolation of the displacement.
So I'm still a bit in the dark, and I cannot find any answer to that question!
Thanks for your help
Tom





RE: Rod Shape Function
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
RE: Rod Shape Function
I have also noticed in Patran, there is only one option for rod element; so I believe the linear shape function is the best option.
What about the other software?
Thanks!
Tom
RE: Rod Shape Function
another day in paradise, or is paradise one day closer ?