Discussion Forum

Hi everyone, I am a beginner trying to perform a fluid structure interaction with imported gemoetry. This geometry consists of a nonuniform hyperelastic object with a cavity and a tube which air will be pumped into the cavity. I am attempting to see how much air is required to be pumped in order to create a given displacement I have managed to plot the surface stress, pressure and velocity, but when I add a deformation plot it gives me the following error:

Cannot evaluate expression.

Undefined variable. - Variable: comp1.u2 - Geometry: geom1 - Boundaries: 1628-1638, 1640-1657, 1660-1665, 1667-1668, 1672-1673, 1676-1687, 1690-1691 Failed to evaluate expression. - Expression: comp1.u2 Undefined variable. - Variable: comp1.spf.U - Geometry: geom1 - Domain: 1 Failed to evaluate expression. - Expression: comp1.spf.U Failed to evaluate operator. - Operator: mean - Geometry: geom1 - Boundaries: 1755-1756 Failed to evaluate expression. - Expression: mean(comp1.spf.U) Failed to evaluate variable. - Variable: comp1.spf.U - Geometry: geom1 - Boundaries: 1755-1756 Failed to evaluate expression. - Expression: comp1.spf.U - Plot: Surface 2

Additionally, I cannot plot the reaction forces. These boundaries with errors are all in the faces where the cavity and the object geometry are coincident, but there doesn't seem to be a particular area or pattern where it occurs. Please ask if you need more information, this is proprietary work and so I am unable to share screenshots of the geometry or the files.

Note: I have used the vague tutorial of filling a water balloon as reference for my setup. I was unable to find any tutorials or forums that address these issues or set up FSI with imported geometry for my case.