r5.03.36 Behavioral law KICHENIN_NL combining elastoplasticity and nonlinear viscoelasticity

Summary:

This document describes behavior model KICHENIN_NL, intended to describe the mechanical response of polyethylene. It combines an elastoplastic branch with linear kinematic work hardening with a nonlinear Maxwell viscoelastic branch. A modeling of large deformations is accessible via kinematics GDEF_LOG.

As a preamble, it should be noted that this documentation is based on the note [Lorentz, 2022]. It only retains the main elements concerning the formulation and numerical integration of the model. Interested readers are referred to this note and its references for further details as appropriate.

• 1. Field of application
  • 1.1. Purpose
  • 1.2. Material parameters
  • 1.3. Internal variables
• 2. Continuous model
  • 2.1. Elastoplastic branch
  • 2.2. Viscoelastic branch
  • 2.3. Post-processing variables
• 3. Digital integration
  • 3.1. Discretized equations
  • 3.2. Elastoplastic branch
  • 3.3. Viscoelastic branch
  • 3.4. Post-processing variables
• 4. Bibliography