Loading Rate Dependence of Tensile Strength Anisotropy of Barre Granite |
| |
Authors: | Feng Dai Kaiwen Xia |
| |
Institution: | (1) Department of Civil Engineering and Lassonde Institute, University of Toronto, Toronto, ON, M5S 1A4, Canada; |
| |
Abstract: | Granitic rocks usually exhibit strongly anisotropy due to pre-existing microcracks induced by long-term geological loadings.
The understanding of the rock anisotropy in mechanical properties is critical to a variety of rock engineering applications.
In this paper, Brazilian tests are conducted statically with a material testing machine and dynamically with a split Hopkinson
pressure bar system to measure both static and dynamic tensile strength of Barre granite. To understand the anisotropy in
tensile strength, samples are cored and labelled using the three principle directions of Barre granite to form six sample
groups. For dynamic tests, a pulse shaping technique is used to achieve dynamic equilibrium in the samples during the dynamic
test. The finite element method is then implemented to formulate equations that relate the failure load to the material tensile
strength by employing an orthotropic elastic material model. For samples in the same orientation group, the tensile strength
shows clear loading rate dependence. The tensile strengths also exhibit clear anisotropy under static loading while the anisotropy
diminishes as the loading rate increases, which may be due to the interaction of pre-existing microcracks. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|