### Strain Driven Analysis

100

views

0

Hello everyone,

Is it possible to perform annonlinear analysis by strain driven ? I mean, I do not want to use any traction or body force but I want to define incremental strain as a boundary condition. How can I define such a input ?

Regards,

Is it possible to perform annonlinear analysis by strain driven ? I mean, I do not want to use any traction or body force but I want to define incremental strain as a boundary condition. How can I define such a input ?

Regards,

Community: FEniCS Project

I do not want to apply $u=u_0\left(x,t\right)$

`u`=`u`_{0}(`x`,`t`) but I want to apply $\varepsilon=\varepsilon_0\left(x,t\right)$`ε`=`ε`_{0}(`x`,`t`) where`Eps = 0.5*(nabla_grad(u) + nabla_grad(u).T)`

written
4 months ago by
Christian

Can you derive a displacement from your desired strain? For instance, if you wanted a 0.01 strain in a bar with length L, you can fix one end an impose a displacement of 0.01*L at the other end. If you cannot do it, I believe you need to use FEM that solve for the strain or stress (mixed methods).

written
4 months ago by
Miguel

For a nonlinear problem that approach will not work. Do you have any example about that problem with mixed methods ?

written
4 months ago by
Christian

Nope, sorry. Do a literature search for mixed methods in elasticity. If you have large deformations and your stress is not symmetric, that will be something to take into account in your search.

written
4 months ago by
Miguel

Please login to add an answer/comment or follow this question.

=uu_{0}(,xt) or $\mathbf{\sigma}\cdot\mathbf{n}=\mathbf{t}_0\left(\mathbf{x},t\right)$·σ=nt_{0}(,xt) on the boundary. You could reformulate this in terms of strain using a constitutive equation for the stress I guess...