Instabilities in stress corrosion and the transition to brittle failure

被引:27
|
作者
Koehn, D
Arnold, J
Jamtveit, B
Malthe-Sorenssen, A
机构
[1] Phys Geol Proc, N-0316 Oslo, Norway
[2] Johannes Gutenberg Univ Mainz, Inst Geowissensch, D-55099 Mainz, Germany
关键词
INTERGRANULAR PRESSURE SOLUTION; SURFACE INSTABILITIES; FRACTURE PATTERNS; MODEL; TRANSFORMATION; BOUNDARIES; SIMULATION; STABILITY; EVOLUTION; KINETICS;
D O I
10.2475/ajs.303.10.956
中图分类号
P [天文学、地球科学];
学科分类号
07 ;
摘要
dStudies on the dissolution of stressed crystals have shown that stress corrosion can lead to roughening of interfaces. The corrosion pattern develops due to gradients in elastic energy along a free crystal surface with an initial roughness. Dissolution will cause further increase in elastic energy, which in turn will speed up dissolution, the so-called Asaro-Tiller-Grinfeld instability. We present a numerical model in order to study the effect of stress corrosion that is observed in physical experiments of interface roughening of brittle salt crystals. In the simulations a salt crystal that is immersed in saturated brine is stressed and dissolution patterns develop. Stress corrosion can lead to an Asaro-Tiller-Grinfeld instability that develops into cusp instabilities and crack-like structures or anti-cracks. The system breaks its symmetry and produces a secondary instability where the number of growing anti-cracks is reduced. This coarsening of the surface roughness is due to stress-shielding effects of growing anti-cracks. Finally, one single anti-crack remains on each side of an initial hole as a "superstructure". The large anti-crack grows at an almost constant speed and eventually leads to brittle failure of the crystal. This mechanism may be important not only for dissolution-precipitation creep but also other phase-transitions and may lead to large scale brittle failure that can be associated with earthquakes.
引用
收藏
页码:956 / 971
页数:16
相关论文
共 50 条