Internal Friction at Low Frequencies Due to Dislocations: Applications to Metals and Rock Mechanics

1971 ◽  
pp. 347-371 ◽  
Author(s):  
WARREN P. MASON
Keyword(s):  
Internal Friction ◽  
Rock Mechanics ◽  
Low Frequencies

On: “Frequency‐independent background internal friction in heterogeneous solids” by Baxter H. Armstrong (GEOPHYSICS, June 1980, p. 1042–1054).

Geophysics ◽  
1981 ◽  
Vol 46 (9) ◽  
pp. 1314-1314 ◽  
Author(s):  
Gábor Korvin
Keyword(s):  
Internal Friction ◽  
Frequency Dependence ◽  
Attenuation Coefficient ◽  
Thermal Conduction ◽  
Heterogeneous Solids ◽  
Low Frequencies ◽  
Novel Approach ◽  
Frequency Independent ◽  
Inherent Frequency

In his recent paper Dr. Armstrong proposes a novel approach based on considerations of thermal conduction and thermoelastic dissipation to explain the observed nearly constant Q behavior toward low frequencies in randomly heterogeneous solids. I feel, however, the fluctuation coefficient R defined by his equation (22) does have an inherent frequency dependence introduced through the [Formula: see text] factors so that the attenuation coefficient A might be a more complicated function of frequency than suggested by equation (24).

Stability of Gas Drainage Borehole Analysis on Rock Mechanics Parameters with Roadway of Complex Stress

2015 ◽  
Vol 723 ◽  
pp. 330-335 ◽  
Author(s):  
Tian Jun Zhang ◽  
Lei Zhang ◽  
Hong Yu Pan ◽  
Chao Zhang
Keyword(s):  
Numerical Simulation ◽  
Internal Friction ◽  
Rock Mechanics ◽  
Vertical Direction ◽  
Friction Angle ◽  
Complex Stress ◽  
Stress Redistribution ◽  
Horizontal Direction ◽  
Gas Drainage ◽  
Drainage Borehole

The pattern of stress redistribution in the effect of circular roadway is analyzed and numerical simulation on stability of gas drainage borehole which is in the area of the stress redistribution was done with FLAC3D. The model of that circular roadway and gas drainage borehole are perpendicularly crossed is established and compute with the Coulomb Mohr criterion. It can be found that the stress of gas drainage borehole decreases with decreasing of internal friction angle and the cohesion value. The stress of gas drainage borehole steep rises where the distances of away from roadway is two times of the diameter and the stress of horizontal direction are larger than the stress of vertical direction.

VERY LOW FREQUENCIES INTERNAL FRICTION MEASUREMENTS OF ICE Ih

1981 ◽  
Vol 42 (C5) ◽  
pp. C5-541-C5-546 ◽  
Author(s):  
J. Tatibouet ◽  
J. Perez ◽  
R. Vassoille
Keyword(s):  
Internal Friction ◽  
Low Frequencies ◽  
Friction Measurements

Amplitude Dependent Internal Friction within a Continuum Simulation

1999 ◽  
Vol 578 ◽  
Author(s):  
P. Alex Greaney ◽  
D. C. Chrzan
Keyword(s):  
Internal Friction ◽  
Elasticity Theory ◽  
Radiation Effects ◽  
Stress Amplitude ◽  
Dislocation Dynamics ◽  
Low Frequencies ◽  
Bias Stress ◽  
Isotropic Elasticity ◽  
Periodic Stress ◽  
Overdamped Limit

AbstractThe mechanical losses due to the bowing of isolated Frank-Read sources under application of periodic loads is studied within a continuum simulation of dislocation dynamics. The dislocations are modelled within isotropic elasticity theory and assumed to be in the overdamped limit. Dislocation radiation effects are neglected. The mechanical losses are studied as a function of bias stress, amplitude of the periodic stress and frequency. The frequencies studied lie between 10 KHz and 1 MHz. Under high stresses applied at low frequencies, a deviation from the expected Lorentzian resonance shape is observed. The physical origins of this deviation are discussed.

Sign in / Sign up

Export Citation Format

Share Document