Experimental Determination of Dissipation Factor in Rock Samples of Different Types and Genesis
V. S. Salyukov, Ya. O. Kutkin, A. S. Voznesensky
National University of Science and Technology-NUST MISIS, Moscow, Russia
Keywords: Lab-scale system, rocks, cyclic testing, mechanical hysteresis, internal mechanical losses, dissipation factor, rayleigh damping
Abstract
The analysis of dynamic events in the earth’s crust should take into account internal mechanical losses (energy dissipation) in rocks. Such dynamic events often have a frequency under 1 Hz. Internal mechanical losses are estimated in terms of the dissipation factor Q -1. Rayleigh damping represents the dissipation factor with respect to the direct and inverse dependence on frequency. The authors performed three-point bending tests of rock samples of different types and genesis. The dissipation factors are calculated for various frequencies of deformation. The empirical dependences of the dissipation factor on the frequency in a range of 0.003-0.100 Hz are approximated by Rayleigh damping. The coefficients of variation and determination are calculated to define conformity between the experiment and model data, the conclusion on the good agreement with the Rayleigh model is made, and the causes of differences between experimental and theoretical results are listed.
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