crevprop.fracture¶
2024 Jessica Mejia
fracture mechanics used in crevasse propagation model
Linear elastic fracture mechanics scheme for crevasse propagation
LEFM based on Weertman’s dislocation theory and application to crevasses with adaptations from van der Veen (1998)
Theory¶
STRESS INTENSITY FACTOR For a fracture to propagate
KI >= KIC
stress @ crev tip must >= fracture toughness of ice where KI is the stress intensity factor which describes the stresses at the fracture’s tip the material’s fracture toughness (KIC)
Functions
| Finite ice thickness correction for the stress intensity factor |
| Functional expression G in KI2 evaluation. |
| KI1 accounting for opening and consider effect of shielding |
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| calculated applied stress (sigma_A) |
| empirical density-depth relationship from Paterson 1994 |
| calculate the squareroot of the difference of squares :param x: :type x: float, int :param y: :type y: float, int |
| calculate elastic crevasse wall displacement from applied stress sigma_T. |
| Stress intensity factor for tensile normal stress |
| KI(2) in units of MPa |
| stress intensity factor component for a water-filled crevasse |
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| integral within the equation for KI(2) van der veen 1998 |
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| find initial crevasse depth for a water-free crevasse |
| ice overburden stress as a function of depth acconting for firn |
| depth dependant near-surface density |
| calculate crevasse penetration depth for a single crevasse |
| Calculate sigma |
| calcualte x+y / x-y |
| Calculate the stress intensity factor's tensile component. |
| Convert water height in crevasse to depth below surface in meters |
| calc water high in crevasse using van der Veen 2007 |