Overview of Plastic Region

In general, the elastic or plastic behaviour of a material can be defined by “Material Type” as a user input. Here, RS3 additionally provides two plastic region related options, to define material behaviour by region. They offer opposite functionalities, and are located under the Materials menu:

1. Add Plastic Regions
2. Exclude Plastic Regions

The functionality of this feature bears resemblance to the SSR region, which is specifically applicable to analyses conducted using the shear strength reduction method.

Add Plastic Regions

A plastic region can be defined with the Add Plastic Regions option. The purpose of defining a plastic region is to focus on a particular area with plastic material, while disregarding the non-linearity of materials outside that region by switching their material type to elastic. This enables faster analysis by considering plasticity only within the specified region.

An option of “Use default material outside of plastic region for advanced constitutive model” is subjected to advanced constitutive models, See the relevant section for more details .

Exclude Plastic Regions

If you desire to exclude the plastic behaviour of material in particular area, you can use the Exclude Plastic Regions option. In switches the material type of the selected area to elastic, while keeping the plastic behaviour for the rest of the domain. One of the key applications is excluding plastic behavior in regions with singularities that may cause non-convergence.

Plastic Region and Material Properties

It is recommended to define material properties prior to create plastic or exclude plastic regions. It is also acceptable to change material properties after creating a region. However, once Add / Exclude plastic regions are defined, it will always be in effect to the designated area.

After the material type is changed by Add / Exclude plastic regions, all other parameters of material properties in the Define Material Properties dialog remain unchanged.

Both Add / Exclude plastic region options are available only to plastic materials. If elastic materials are involved, see respective option topics for more information.

Hydraulic Properties

The hydraulic properties of a material will not be affected by Add / Exclude plastic regions.

Staged Materials

The Add / Exclude plastic regions only affects the material type, the staged materials will work normally.