pyrocko.modelling.cracksol

Analytical crack solutions for surface displacements and fault dislocations.

Classes

GriffithCrack(**kwargs)

Analytical Griffith crack model.
class GriffithCrack(**kwargs)[source]

Bases: Object

Analytical Griffith crack model.

♦ width

float, default: 1.0

Width equals to 2 \cdot a.

♦ poisson

float, default: 0.25

Poisson ratio \nu.

♦ shearmod

float, default: 1000000000.0

Shear modulus \mu [Pa].

♦ stressdrop

numpy.ndarray (pyrocko.guts_array.Array), default: array([0., 0., 0.])

Stress drop array:[\sigma_{3,r} - \sigma_{3,c}, \sigma_{2,r} - \sigma_{2,c}, \sigma_{1,r} - \sigma_{1,c}] = [\Delta \sigma_{strike}, \Delta \sigma_{dip}, \Delta \sigma_{tensile}].

property a

Half width of the crack in [m].

disloc_infinite2d(x_obs)[source]

Calculation of dislocation at crack surface along x2 axis.

Follows equations by Pollard and Segall (1987) to calculate dislocations for an infinite 2D crack extended in x3 direction, opening in x1 direction and the crack extending in x2 direction.

Parameters:

x_obs (ndarray: (N,)) – Observation point coordinates along x2-axis. If x_{obs} < -a or x_{obs} > a, output dislocations are zero.

Returns:

Dislocations at each observation point in strike, dip and tensile direction.

Return type:

ndarray: (N, 3)

disloc_circular(x_obs)[source]

Calculation of dislocation at crack surface along x2 axis.

Follows equations by Pollard and Segall (1987) to calculate displacements for a circulat crack extended in x2 and x3 direction and opening in x1 direction.

Parameters:

x_obs (ndarray: (N,)) – Observation point coordinates along axis through crack centre. If x_{obs} < -a or x_{obs} > a, output dislocations are zero.

Returns:

Dislocations at each observation point in strike, dip and tensile direction.

Return type:

ndarray: (N, 3)

displ_infinite2d(x1_obs, x2_obs)[source]

Calculation of displacement at crack surface along different axis.

Follows equations by Pollard and Segall (1987) to calculate displacements for an infinite 2D crack extended in x3 direction, opening in x1 direction and the crack tip in x2 direction.

Parameters:

  • x1_obs (ndarray: (M,)) – Observation point coordinates along x1-axis. If x1_obs = 0., displacment is calculated along x2-axis.

  • x2_obs (ndarray: (N,)) – Observation point coordinates along x2-axis. If x2_obs = 0., displacment is calculated along x1-axis.

Returns:

Displacements at each observation point in strike, dip and tensile direction.

Return type:

ndarray: (M, 3) or (N, 3)