Testing method for viscoelastic coefficient of short rock bar based on viscoelastic wave propagation analysis

Abstract

The invention relates to a testing method for a viscoelastic coefficient of a short rock bar based on viscoelastic wave propagation analysis. The testing method comprises the following steps: establishing a rock bar viscoelastic constitutive equation and a one-dimensional viscoelastic wave propagation control equation; designing a one-dimensional viscoelastic stress wave program based on the one-dimensional viscoelastic wave propagation control equation, a transmission reflection theory and a viscoelastic damage theory; simulating an impact test by using the one-dimensional viscoelastic stress wave program; inputting loading waves and comparing strain waves obtained by simulating the impact test with verifying waves; and enabling the simulated strain waves to be consistent with the verifying waves in waveform by adjusting parameters, and further obtaining the viscoelastic coefficient of the shock bar. According to the testing method disclosed by the invention, the viscoelastic coefficient obtained by a continuous error trial method of the simulation test is more reasonable; in a dynamic impact test, one complete waveform only needs to be tested to serve as a loading waveform, and the other verifying waveform does not require superposition and completeness, so that the length of the shock bar in the test can be shortened, and the testing of the viscoelastic coefficient of natural rocks is facilitated.

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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