Effect of Multiple Weak Impacts on Evolution of Stresses and Strains in Geomaterials under Complex Loading
V. P. Kosykh, A. S. Teleguz
Chinakal Institute of Mining, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Torsion, compression, complex loading, mechanical properties of geomaterial, sample testing, dynamic loads, stress-strain behavior, stress relaxation, axial strain
Abstract
The article describes the experimental investigations of stresses and strains in a tubular sample made of an equivalent geomaterial subjected to static compression, torque and multiple weak impacts. The tests show that the sample pre-loaded by the static compression and then additionally loaded by the torque at the shearing stresses of 5-7% of the compression stresses elongates and its diameter reduces and the compressive stresses grow. This process lasts for 120-200 h. The additional loading of the sample by the multiple weak impacts gradually leads to the stress relaxation and to the increase of the axial and circumferencial strains. The process of relaxation is nonmonotonous, with the stress picks and drops. During loading, the elastic energy accumulates and releases in the sample with a period of 80-120 h.
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