I have a Validation > Analysis > General > “Material Poisson’s ratio is invalid for 2D elements (0 < v < 0.5)” error. Why do I get this and how do I resolve it?

Environment

Not environment-specific

Question

Answer

Tekla Structural Designer uses the theory of isotropic linear elasticity so the modulus of elasticity, E is related to the shear modulus, G by way of Poisson's ratio, v.

Poisson’s ratio is the ratio of lateral strain to longitudinal strain in a material subjected to loading.

The Poisson's ratio for a wide range of materials fall within a lower limit of -1.0 and an upper limit of +0.5. Since most common materials become thinner in cross section when stretched, the Poisson's ratio is positive and hence in Tekla Structural Designer we only allow values within this positive range [> 0 < 0.5].

You will obtain this error if you create a user defined concrete material property via the Home ribbon tab > Materials > Material page, using the Add.. button with a Poisson’s ratio, v specified outside the range [> 0 < 0.5], and then create an element within the model that uses this material.

To resolve the issue, the poisson’s ratio for the material specified within the validation branch needs to be edited via the Home ribbon tab > Materials dialog to within the range [> 0 < 0.5].

Concrete typically has a Poisson’s ratio in the range of 0.1 to 0.2.