权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Visualization and simulation of rock specimen fracture processes using micromechanics tests

使用微观力学测试对岩石样本断裂过程进行可视化和模拟

基本信息

批准号：
15560699
负责人：
ITAKURA Ken-ichi
金额：
$ 2.37万
依托单位：
Muroran Institute of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-15560699/
关键词：
Micromechanics Tests Micro-specimen Crack Growth Complexity Visualization Discrete Element Method DEM Simulation

项目摘要

A micromechanics test was carried out to elucidate crack growth and investigate the influence of structural complexity in rock specimens with rock strength. That test is a loading test on a microscope stage using small specimen (5×6×1mm). Benefits of this test are that it readily depicts the structural configuration of rock components of rock specimens. It is also easy to visualize the growth of cracks passing through the specimen. After micromechanics tests, fracture simulations using discrete element method (DEM) were conducted using obtained data.The following salient results were obtained :1.Small specimens were prepared from a granite block in three orthogonal directions (H, G and R). Microscopic observation showed that each specimen had a dominant orientation of pre-existing cracks. Tensile strength and its strain were highest in the H specimen and lowest in the R specimen, as shown also by results obtained from usual tensile tests.2.Tensile strength values from micromechanics tests are smaller by about 17% than those from conventional tensile tests.3.Visualization of crack growth shows that a pie-existing crack is an onset of tensile crack growth in the R specimen. The shear crack slides before rupturing in G and H specimens.4.The complexity of the configuration in black-mica influenced the tensile strength of the granite specimen. That is, the higher the complexity index becomes, such as that of the fractal dimension of the black-mica outline, the smaller the tensile strength is.5.Fracture simulation of DEM for a 3D specimen model including pie-existing cracks shows that a similar tendency of tensile strength and its strain are obtained from micromechanics tests for H, G, and R specimens.6.The fracture process and fragmentation differed depending on the orientation of pre-existing cracks in the model specimens.

通过细观力学试验研究了岩石试件的裂纹扩展规律，并探讨了岩石结构复杂性对岩石强度的影响。该试验是在显微镜载物台上使用小试样（5×6×1mm）进行的载荷试验。该试验的好处是，它很容易描绘岩石样本的岩石成分的结构配置。也很容易看到穿过试样的裂纹的生长。在细观力学试验的基础上，采用离散单元法（DEM）对花岗岩试件进行了断裂模拟，得到了以下主要结果：1.在正交三个方向（H、G和R）上制备了花岗岩试件。微观观察表明，每个试样都有一个占主导地位的方向预先存在的裂纹。拉伸强度和应变在H试样中最高，而在R试样中最低，这也与常规拉伸试验结果一致。2.细观力学试验的拉伸强度值比常规拉伸试验的拉伸强度值小17%左右。G型和H型试样中剪切裂纹在破裂前先滑动。4.黑云母中结构的复杂性影响花岗岩试样的抗拉强度。5.对含裂纹的三维试件模型进行离散元法断裂模拟，结果表明，H、G、6.断裂过程和破碎取决于模型试样中预先存在的裂纹的取向。