4.1.1.6.1.6. pyfem.materials.Isotropic module

class Isotropic(props)[source]

Bases: BaseMaterial

Isotropic linear elastic material model.

This class implements a standard isotropic linear elastic material model using Hooke’s law. The material behavior is fully characterized by two elastic constants: Young’s modulus (E) and Poisson’s ratio (nu).

The model can operate in two modes: - Total formulation: stress = H · strain - Incremental formulation: Δσ = H · Δε

E

Young’s modulus.

Type:: float

nu

Poisson’s ratio.

Type:: float

H

6x6 elastic stiffness matrix (Hookean matrix).

Type:: ndarray

incremental

Flag for incremental or total formulation.

Type:: bool

outLabels

Labels for stress components.

Type:: list of str

Notes

The stress and strain vectors follow Voigt notation: [σ11, σ22, σ33, σ23, σ13, σ12]

getStress(deformation) → Tuple[ndarray, ndarray][source]

Compute stress and material tangent matrix.

Parameters:

deformation (object) –

Deformation object containing strain information. Must have: - strain : ndarray

Total strain vector (for total formulation).

dstrainndarray
Strain increment vector (for incremental formulation).

Returns:

sigma (ndarray) – Stress vector in Voigt notation [σ11, σ22, σ33, σ23, σ13, σ12].
H (ndarray) – Material tangent stiffness matrix (6x6).

getTangent() → ndarray[source]

Get the material tangent stiffness matrix.

Returns:: Material tangent stiffness matrix H (6x6).
Return type:: ndarray