FEM MaterialMechanicalNonlinear/ro

Description

Creates a nonlinear mechanical material. Currently, only plasticity with simple (isotropic) hardening is available. introduced in version 1.0: Kinematic hardening is also available.

Usage

1. To create a new MaterialMechanicalNonlinear object do the following:
   • Add a Material for solid first and select it.
   • Click the Nonlinear mechanical material button or choose the Model → Materials → Nonlinear mechanical material‏‎ option from the menu.
2. To edit an existing MaterialMechanicalNonlinear object:
   • Select it in the Tree view.
   • Select the material model (isotropic (simple) hardening or introduced in version 1.0: kinematic hardening).
   • Define yield points (stress [MPa] vs plastic strain). The first point must have a zero plastic strain. Press the ... button next to DateYield Points to input the points using a user-friendly list. The syntax is described in the Notes section.

Notes

• In FreeCAD 0.19 and older versions, only 3 yield points can be specified. Since version 0.20 a list of yield points can contain as many as required.
• The syntax should be:

stress_1, 0
stress_2, plastic_strain_2
...

With dot as the decimal separator since that's what CalculiX uses.

For example to define a bilinear model with hardening for S275 steel:

275, 0
490, 0.2

Or, to define perfect plasticity with no hardening for this material:

275, 0