Material Parameters

The material parameters \(k\), \(d_0\), \(\lambda_s\), and \(d_s\) are explained in the section Material.

../_images/fiber.png

Meaning of the parameters

Parameter

Meaning

\(k\)

Stiffness of the material in the linear regime.

\(d_0\)

Decay parameter in the buckling regime. If omitted, the material shows no buckling but a linear response under compression.

\(\lambda_s\)

Stretch at which strain stiffening starts. If omitted, the material shows no strain stiffening.

\(d_s\)

How strong the strain stiffening is. If omitted, the material shows no strain stiffening.

Setting only \(k\) and omitting the other three gives a linear material, which is what LinearMaterial does.

Values used in the examples

These are the parameter sets the bundled examples run with. They are starting points, not reference values for collagen in general: the parameters depend strongly on concentration, batch and polymerisation conditions, so for your own gel they have to be fitted to a rheological measurement or taken from a publication that characterised the same preparation.

Used by

\(k\)

\(d_0\)

\(\lambda_s\)

\(d_s\)

Notes

Single cell, organoid and brightfield examples

6062

0.0025

0.0804

0.034

the default in most examples

Dynamical single cell example (NK cells)

1449

0.0022

0.032

0.055

described in the interface as collagen I, 1.2 mg/ml

Linear material

Young’s modulus \(\times\) 6

LinearMaterial, by definition