4.1.1.6.1.20. pyfem.materials.ThoulessModeI module

class ThoulessModeI(props: Mapping[str, Any])

Bases: BaseMaterial

Mode-I cohesive zone model following Thouless.

Parameters:

props (Mapping[str, Any]) – Material properties expected by BaseMaterial to populate the attributes used here, notably Gc, d1d3, d2d3 and Tult.

getStress(deformation: Any) → Tuple[ndarray, ndarray]

Compute traction and consistent algorithmic tangent.

Expects deformation.strain to provide the normal opening at index 0. Only the normal traction component is modeled in this material; the shear traction remains zero.

Parameters:

deformation (Any) – Object with attribute strain (NumPy array-like) containing the normal opening at index 0.

Returns:

A tuple (stress, tang) where stress is a length-2 array [Tn, Ts] and tang is the 2x2 algorithmic tangent. Only the (0, 0) component is non-zero in this model.

Return type:

Tuple[np.ndarray, np.ndarray]

Notes

Also updates self.outData with the computed stress.