Publication Date:
2019-03-01
Description:
Opening-mode fractures, such as joints, veins, and dykes, frequently exhibit power-law aperture-to-length scaling, with scaling exponents typically ranging from 0.5 to 2. However, published high quality outcrop data and continuum-based numerical models indicate that fracture aperture-to-length scaling may be nonuniversal, with scaling being superlinear for short fractures and sublinear for long fractures. Here we revisit these published results by means of a particle-based lattice solid model, which is validated using predictions from linear elasticity and linear elastic fracture mechanics. The triangular lattice model composed of breakable elastic beams, with strengths drawn from a Weibull distribution, is used to investigate the fracture aperture-to-length scaling that emerges in a plate subjected to extension. The modeled fracture system evolution is characterized by two stages which are separated by the strain at which peak-stress occurs. During the pre-peak-stress stage, aperture-to-length scaling is universal with a power-law exponent of about one. Shortly after the material has attained its maximum load bearing capacity, which coincides with the formation of a multiple-segment fracture zone, aperture-to-length scaling becomes nonuniversal, with power-law exponents being consistent with earlier studies. The results presented here confirm that deviation from universal scaling laws is a consequence of fracture interaction. More specifically, the onset of nonuniversal aperture-to-length scaling coincides with the formation of a multiple-segment fracture zone.
Print ISSN:
2169-9313
Electronic ISSN:
2169-9356
Topics:
Geosciences
,
Physics
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