کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
6433771 1636754 2014 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
A combined complex electrical impedance and acoustic emission study in limestone samples under uniaxial loading
ترجمه فارسی عنوان
امپدانس پیچیده الکتریکی و انتشار صوتی در نمونه های سنگ آهک تحت بارگیری دو طرفه
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
چکیده انگلیسی


- Electrical properties and AE of limestone during uniaxial stress are investigated in detail.
- Electrical conductivity increases upon uniaxial stress.
- Negative values of effective activation volume are observed.
- Ac-conductivity during linear loading is strongly correlated with the AE activity.

In the present work, complex electrical impedance measurements in the frequency range of 10 mHz to 1 MHz were carried out in conjunction with acoustic emission monitoring in limestone samples subjected to linear and stepped-like uniaxial loading, up to ultimate failure. Cole-Cole plots of the complex impedance during the stepped loading of limestone have been used to discriminate the contributions of grains interior, grain boundaries and electrode polarization effects to the overall electrical behavior. The latter is well-described with an equivalent-circuit model which comprises components of constant phase elements and resistances in parallel connection. Electrical conductivity increases upon uniaxial loading giving rise to negative values of effective activation volume. This is a strong experimental evidence for the generation of transient electric signals recorded prior to seismic events and may be attributed to charge transfer (proton conduction) due to cracks generation and propagation as a result of the applied stress. The time-series of ac-conductivity at two distinct frequencies (10 kHz, 200 kHz) during linear loading of limestone samples exhibits a strong correlation with the acoustic emission activity obeying the same general self-similar law for critical phenomena that has been reported for the energy release before materials fracture.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Tectonophysics - Volume 637, 10 December 2014, Pages 198-206
نویسندگان
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