ZenerElement

Source: models/solid_mechanics/viscoelasticity/ZenerElement.py

Zener (Standard Linear Solid) viscoelastic model: an equilibrium spring in parallel with a Maxwell branch. The total stress is \(\boldsymbol{\sigma} = (E_\infty + E_M) \boldsymbol{\varepsilon} - E_M \boldsymbol{\varepsilon}_v\), and the Maxwell-branch viscous strain evolves as \(\dot{\boldsymbol{\varepsilon}}_v = E_M (\boldsymbol{\varepsilon} - \boldsymbol{\varepsilon}_v) / \eta_M\).

Inputs

strain — input · SR2 · required

Total strain

viscous_strain — input · SR2 · required

Viscous strain in the Maxwell branch

Outputs

stress — output · SR2 · required

Total stress

viscous_strain_rate — output · SR2 · default viscous_strain_rate

Optional name for the derived output (defaults to ‘viscous_strain_rate’, i.e. the ‘viscous_strain’ variable name with the ‘_rate’ suffix).

Parameters

equilibrium_modulus — parameter · Scalar · required

Equilibrium spring modulus

maxwell_modulus — parameter · Scalar · required

Maxwell branch spring modulus

maxwell_viscosity — parameter · Scalar · required

Maxwell branch dashpot viscosity