A Viscosity Coefficient Test Method for Short Rock Rods Based on Viscoelastic Wave Propagation Analysis

Abstract

The invention relates to a short rock rod viscosity coefficient testing method based on viscoelastic wave propagation analysis, which includes the following steps: establishing a rock rod viscoelastic constitutive equation and a control equation for one-dimensional viscoelastic wave propagation; based on one-dimensional viscoelastic wave propagation Design a one-dimensional viscoelastic stress wave analysis program based on the propagation control equations, transmission and reflection theory, and viscoelastic damage theory; use the one-dimensional viscoelastic stress wave analysis program to simulate the impact test, input the loading wave, and simulate the strain wave obtained from the impact test with verification The waves are compared, and the parameters are adjusted to make the simulated strain waveform consistent with the verification waveform, and then the viscosity coefficient of the rock rod is obtained. The viscosity coefficient obtained by the present invention through continuous trial and error through simulation tests is more reasonable; in the dynamic impact test, only one complete waveform is measured as the loading waveform, and the other verification waveform does not require whether there is superposition and completeness, which can shorten the test time. The length of the rock rod is conducive to testing the viscosity coefficient of natural rocks.

Description

technical field [0001] The invention relates to a rock viscosity coefficient test method, in particular to a short rock rod viscosity test method based on viscoelastic wave propagation analysis. Background technique [0002] In rock mass engineering such as mining, tunnel excavation, and hydropower station construction, the mechanical vibration generated by rock drilling and blasting and the explosion stress wave generated during the explosion of explosives will cause disturbances in the surrounding rock medium and propagate outward in the form of waves. There are various structural planes and joints in the surrounding rock, and the propagation of external disturbances in the jointed rock mass will cause energy attenuation and waveform dispersion. Some rocks containing micro-defects and water not only exhibit elastic properties but also certain viscous properties. , using the equivalent medium method, the propagation of stress waves in jointed rock mass can be equivalent to ...

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Problems solved by technology

[0009] The above test method of viscosity coefficient has the following disadvantages: first, the attenuation coefficient obtained by equation (1) is a function of frequency, so the viscosity coefficient finally calculated is also a function of frequency and is not a fixed value, which needs to be determined according to the main frequency The viscosity coefficient of the rock rod; secondly, to test the strain waveform at two points on the rock rod, it is necessary to ensure that the length of the rock rod can measure two complete loading waveforms, which requires a higher length of the rock rod, and the natural rock drilled The length of the rod is relatively short, so it is difficult to make rock rods that meet the requirements

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