DENG Hua-feng, WANG Chen-xi-jie, LI Jian-lin, et al. Influence mechanism of loading rate on tensile strength of sandstone[J]. 2018, 39(S1): 79-88.
DOI:
DENG Hua-feng, WANG Chen-xi-jie, LI Jian-lin, et al. Influence mechanism of loading rate on tensile strength of sandstone[J]. 2018, 39(S1): 79-88.DOI: 10.16285/j.rsm.2017.2530.
Influence mechanism of loading rate on tensile strength of sandstone
In order to study how the tensile strength of sandstone influenced by loading rate
a series of splitting tests are carried out with five loading rates. Based on the comprehensive analysis of the splitting tensile strength
destructive features
the change rule and correlation between microstructure of the splitting surface and energy parameters
the results show that: (1) The split tensile strength of sandstone gradually decrease as loading rate increase
and generally go slow after the first steep upward trend. When loading rate is between 0.01 kN/s to 0.10 kN/s
the tensile strength grew significantly and then tended to slow down at 0.1 kN/s to 1.00 kN/s. (2) Total energy the sample absorbed increase as loading rate increase
and the ratio of elastic strain energy to total energy increases while dissipated energy go down
the time when the crack propagation formed into splitting surface is an order of magnitude less
which indicates the sudden destruction of rock sample enhanced resulted by release of elastic strain energy when peak stress reached
which result in tensile strength enhanced and increasingly complicated micro morphology characteristics. (3) During the rock splitting test
loading rate
energy parameter
features of splitting surface and tensile strength are closely related; first of all
the loading rate affects the total amount and distribution of energy
and the changes in energy parameters affects its destruction process and features of splitting surface; finally
the difference in tensile strength shows. The related analysis methods and ideas references can provide a better reference for similar tests.