WEN Lei, LIANG Xu-li, FENG Wen-jie, et al. An investigation of the mechanical properties of sandstone
under coupled static and dynamic loading[J]. 2020, 41(11): 3540-3552.
DOI:
WEN Lei, LIANG Xu-li, FENG Wen-jie, et al. An investigation of the mechanical properties of sandstone
under coupled static and dynamic loading[J]. 2020, 41(11): 3540-3552.DOI: 10.16285/j.rsm.2020.0214.
An investigation of the mechanical properties of sandstone
under coupled static and dynamic loading
Through the application of SHPB (split Hopkinson pressure bar) test
this research firstly analyzed the law of damage under the cyclical impact on grey sandstone samples with the condition of static load. After that
to obtain the sample failure mode and speculate the relationship between dynamic stress and strain
the static-dynamic loading experiments on pre-damaged rock samples were also performed. Finally
based on the principle of strain equivalence
the total damage variable under the condition of static-dynamic loading was analyzed to derive the damage evolution equation to explain the relation of damage constitutive. Based on above tests
the research suggests: (1) the damage variable of rock sample can be divided into three stages during the process of cyclical impact
which are rapid increase
low-speed development and high-speed development
meanwhile
a higher axial pressure will lead to a lower damage variable in the stage of low-speed development; (2) compared with pre-damaged sample
the effect of strain rate enhancement on intact samples is more significant under the same condition; (3) the joint impact of pre-damaged variable ( ) and static-load damage variable ( ) might be negative
which therefore explained the fact that the dynamic strength increases with the static pressure under the condition of static-dynamic loading; (4) the constructed constitutive relation is also in perfect agreement with the curve of test value
which can in turn show a consistency between the macro- and micro- damage of the rock and then reflect the nonlinear influence of cyclical impact and static loading on total damage development.