Quantitative Observation of the Micromechanics of the Brittle-Ductile Transition in Rocks

破坏机制由脆性断裂向脆性断裂的转变 塑性流动在理解构造物理学中很重要， 地壳的强度，以及现场变形的方式 规模 最近在三个领域的研究产生了新的见解， 脆塑性转变的物理学和力学： 获取高质量的机械数据，系统化 变形显微组织的观察，以及变形显微组织研究的进展， 岩石受压破坏的理论模型。 定性的显微结构观察提供了信息 各种变形机制 操作，估计应变分配，并确定 裂纹形核机制 PI将继续工作， 三轴力学试验脆韧转变 方解石、钙长石、橄榄岩、 和dilemma。 定量微观结构分析， 变形的微观力学是其中的一个重要部分 study. 声发射测量也将在 选定数量的实验，以及轴向和体积应变 测试期间将进行测量。

The transition in failure mechanism from brittle fracture to plastic flow is important in understanding tectonophysics, the strength of the crust, and the style of deformation at the field scale. Recent studies in three areas have yielded new insight into the physics and mechanics of the brittle-plastic transition: acquisition of high quality mechanical data, systematic observations of deformation microstructures, and advances in the theoretical modeling of the failure of rocks in compression. Qualitative microstructural observations have provided information on the conditions under which various deformation mechanism operate, estimates of strain partitioning, and identification of crack nucleation mechanism. The PI will continue work on the brittle-ductile transition by performing triaxial mechanical tests on natural and synthetic rocks of calcite, anorthite, peridotite, and diabase. Quantitative microstructural analyses to understand the micromechanics of deformation are an important part of this study. Acoustic emission measurements will also be performed on a selected number of experiments, and axial and volumetric strain measurements will be made during the tests.