The specific non-linear elastic hysteresis of rocks under cyclic uniaxial tension

The paper discusses the estimation of the parameters of elastic hysteresis of rock samples. The parameters of elastic hysteresis are determined in a certain range of elastoplastic sublimit deformations and for certain conditions. The paper substantiates the choice of rock and sample preparation, describing a static mechanical testing technique that governs the behavior of rock samples under given stresses and the response of the elastic properties to loading/unloading. The paper analyzes the experimental results of deformation of rock samples under conditions of elastic hysteresis and explains the arising nonlinear effects using the principles of a micromechanical model. The micromechanical model and other approaches substantiating the nonlinear nature of rock sample deformation are considered. The paper discusses the approaches and results that explain residual deformations at the initial stage of cyclic loading and stabilization of the structure of geomaterial at subsequent stages, assessing its nonlinear elastic properties. Based on the results, models for various rocks are proposed to determine the nonlinear parameters of elastic hysteresis: static elastic moduli and hysteresis parameter. Based on the micromechanical model, the generalized density of cracks in rock samples is determined, thereby making it possible to estimate the degree of nonlinearity of elastoplastic deformation.

Vysotin N. G. The specific non-linear elastic hysteresis of rocks under cyclic uniaxial tension. MIAB. Mining Inf. Anal. Bull. 2021;(4-1):148—157. [In Russ]. DOI: 10.25018/0236_1493_2021_41_0_148.

Vysotin N. G., Senior Lecturer, kalgani@yandex.ru, National Research Technological University «MISiS» , Moscow, Russia.

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