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U.S. Department of Energy
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A finite element material model for microfracture-damaged brittle rock. [SANCHO code]

Technical Report ·
OSTI ID:6464045

A continuum damage model based on the mechanics of microcrack growth has been implemented in the finite element code SANCHO. The model incorporates the effects of the nucleation, growth and coalescence of microcracks on the deformation of brittle materials, such as rock, under compressive loading. The material subroutine keeps track of both the magnitude and direction of microcrack growth in each element so that the induced anisotropy due to crack growth in preferred directions and the stress history dependence of microcrack growth are properly taken into account. In addition, the model allows for interaction among neighboring microcracks, which leads to coalescence and subsequent material failure or softening. A damage vector, which is calculated from the crack distribution in each element, is used as an internal variable to compute the effective elastic moduli at each stage of the deformation. Results of several sample calculations using the model are presented and methods for determining the required material parameters are discussed.

Research Organization:
Sandia National Labs., Albuquerque, NM (USA)
DOE Contract Number:
AC04-76DP00789
OSTI ID:
6464045
Report Number(s):
SAND-87-1227; ON: DE87012511
Country of Publication:
United States
Language:
English