Linear & NonLinear Analyses

[Miko]

Hi all.. I am beginner in Pro/MECHANICA and I would like to know what is the different between Linear and nonlinear analyses...Iwould like to know where and whenis useful or issome kind of advantage for me to use Linear and when nonlinear analyses...Some exampleswould be great...


Thanks in advance

 

[dgeesaman]

Linear just means the solution can be done in one big mathematical step.

Nonlinear means that the effects in your analysis depend on each other in a way that prevents the solver from marching straight through to the answer. So you wait longer. But it's not always that simple.

Some features in FEA that are non-linear (and this is not restricted to mechanica):
- plasticity or non-linear material models (when young's modulus isn't enough)
- contact
- fluid-structure interactions
- any many more.

Mechanica does basic contact, off the top of my head I think that's it for nonlinear capabilities.

Mechanica is pretty friendly to use to run non-linear solutions, but watch the final error estimate and be sure to run the linear approximation of your analysis first as a reference point.

Dave

 

[headrush]

I suggeest you perform a bucklng analysis before you run non-linear.When you hit the first buckling mode the non-linear analysis will stop. So all your buckling modes must be above your applied non-linear load(s), otherwise the analysis will not succeed.

 

[Israr]

dgeesaman,


looks like you are experienced user of mechanica. I would like to know your profile which is empty. Also please paticipate in discussion forums like this one.


Miko,


To tell you in a nutshell Pro/Mechanica is best which you solve linear material problems in elastic range. Although mechanica can handle problems of contact, bucking and large deformation I would say don't use it in these cases or if you have no choice atleast verify it using other means.


Israr

 

[Miko]

thank you all