Influence of rate of change in stress field to the fracture phenomena

应力场变化率对断裂现象的影响

• 批准号: 60550445
• 负责人: OGINO Shoji
• 金额: $ 1.02万
• 依托单位: Yamaguchi University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1985
• 资助国家: 日本
• 起止时间: 1985 至 1986
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-60550445/
• 关键词: triaxial test; confining pressure; strain rate

In the mechanical testing of metals, the applied stress is usually uniaxial. However, for rocks, three principal stresses are commonly non zero, because the triaxial stress state can effectively simulate overburden stress. The usual triaxial tests are carried out by stressing the rock under confining pressure. However, in most practical situations, the fracture of the rock occurs due to a creation of the free surfaces such as an under-ground openings. Then the maximum stress (tensile stress is taken to be positive) should be decreased. In this research, we introduce an new experimental procedure, depressing test. The new test start from the hydrostatic stress state, where the axial strain rate is kept constant. The confining pressure is decreased at various depressing rate simultaneously. Rock specimens fractured violently, while in usual confined test rock specimen behave ductile under relatively high confining pressure.

在金属的力学测试中，施加的应力通常是单轴的。然而，对于岩石，三个主应力通常不为零，因为三轴应力状态可以有效地模拟上覆应力。通常的三轴试验是通过在围压下对岩石施加应力来进行的。然而，在大多数实际情况下，岩石的断裂是由于自由表面的产生而发生的，例如地下开口。然后，最大应力（拉应力取为正）应减小。在本研究中，我们介绍了一种新的实验程序，压抑试验。新的试验从静水应力状态开始，其中轴向应变率保持恒定。围压以不同的降压速率同时降低。岩石试件破裂剧烈，而在通常的围压试验中，岩石试件在较高的围压下表现为韧性。

项目成果

荻野正二: 日本鉱業会誌.

Shoji Ogino：日本矿业协会杂志。

Shoji, Ogino, Yoshiaki Mizuta and Osam Sano: "On the depressing test, a new method" J. Sci. Mater. Sci., Japan.

Shoji、Ogino、Yoshiaki Mizuta 和 Osam Sano：“关于抑郁测试，一种新方法”J. Sci。