Abstract This paper presents a method for continuous multiscale observation of uniaxial compressive tests Carrara marble specimens containing single preexisting artificially created flaw. The experiments aim at analyzing the associated mesoscale‐macroscale phenomena in fracture process specimens. In macroscale, crack types are observed and characterized by optical using camcorder high‐speed camera. mesoscale, analyzed moment tensor inversion acoustic emission. For experimental investigation...

Abstract Clustering of earthquake magnitudes is still actively debated, compared to well-established spatial and temporal clustering. Magnitude clustering not currently implemented in forecasting but would be important if larger magnitude events are more likely followed by similar sized events. Here we show statistically significant present many different field laboratory catalogs at a wide range scales (mm 1000 km). It universal across fault types tectonic/induced settings, while results...

Rock fracture mechanics and accurate characterization of rock are crucial for understanding a variety phenomena interested in geological engineering geoscience. These range from very large-scale asymmetrical fault structures to the scale projects laboratory-scale tests. Comprehensive study can involve mechanical modeling, site or post-mortem investigations, inspection on point cloud source locations form earthquake, micro-seismicity, acoustic emission. This presents comprehensive data...

Experimental rock mechanics testing provides a controlled and effective method for measuring physical properties, their dependencies, evolution due to the addition of localized microcracks. To understand contributions microcracks first order changes in compliance, behavior initial undamaged properties material should be comprehensively investigated as function stress, load path, history. We perform comprehensive study elastic dependence on variety materials exhibiting nonlinearity, varying...

The research introduced a new method for land-use classification by merging deep convolutional neural networks with modified variant of metaheuristic optimization technique. methodology involved utilizing the VGG-19 model feature extraction, dimensionality reduction, and stacked autoencoder optimized boosted version Big Bang Crunch Theory. Through testing on Aerial Image Dataset UC Merced Land Use comparing it other published works, approach showed higher accuracy compared to current...

Rapid identification of highway cracks is greatly significant for maintenance. In recent years, the use unmanned aerial vehicles to collect images road automatic recognition has become a topic concern many researchers. Based on this, raise accuracy and efficiency crack recognition, method based vehicle improved Otsu developed. Firstly, certain processing techniques are applied captured by vehicle, such as grayscale equalization, reduce computational complexity facilitate subsequent image...

<div class="section abstract"><div class="htmlview paragraph">To accurately identify the fault types of proton exchange membrane fuel cell (PEMFC) systems under continuously varying operating currents, this study develops a comprehensive PEMFC system model and proposes robust diagnosis method based on ResNet50 convolutional neural network (CNN) transfer learning (TL). Initially, using Matlab/Simulink, is constructed electrochemical reaction mechanisms empirical formulas that...

In view of borehole collapse in testing horizontal wells, a calculation model for volume open-hole multiple-weak-plane formation was set up to analyze the factors affecting volume. It compared with single-weak-plane by field application. After analyzing influences fracture occurrence, well-bore azimuth, in-situ stress anisotropy, number weak planes and fluid density on volume, this study reveals: When dip is small, big stability poor; big, varies greatly change azimuth trend; The maximum...

Heterogeneity is an intrinsic characteristic of rock and rock-like (brittle) materials. The statistical homogeneity assessment using Weibull distribution with a index, m, one the most widely used methods for characterizing brittle material heterogeneity. critical issue this method to obtain m values. For previous studies, linear least-squares (LLS) technique was values during numerical modeling, which involves ranking failure strength data brittle-material model elements in ascending order....

SUMMARY The behaviour of discontinuities in rock mass have been experimentally investigated extensively for decades by a type laboratory analogue flawed specimens, taking the artificially prepared flaw(s) as discontinuity(ies). role macroscale controlling structure has generally neglected. Here, we conduct detailed characterizations acoustic emission (AE) from fracture process on pre-flawed specimens under loading. Though same phenomena literature can be reproduced within our tests,...

Abstract Combining multiphysics observations in the laboratory, we present novel phenomena for analogue between rock fracture and seismicity. We show, first time a laboratory setting, how large‐scale flaw can facilitate “non‐local triggering”—remotely triggered damage mass. Results prove analogues of evolution to natural seismicity including several lab‐analogues on model predictions beyond power law. observe under specimen‐scale criticality relatively small AE perturbation occurring at...

SUMMARY The development of shear-type fault analogues from intact rock at the laboratory scale provides a unique opportunity for investigating tectonic-scale phenomena through lens geophysics. transition fracture creation to slip must exist. We observe three spontaneously temporally well-separated mechanical instabilities attributed continuous evolution between two artificial flaws. Their separation is validated with rapid stress drops and stabilizations, periodical acoustic emission (AE)...

ABSTRACT: Laboratory experimental rock mechanics studies with acoustic emission (AE) recordings are often viewed as analogous to investigations of field-scale phenomena. The application U-Net for processing seismic waveform has achieved widely recognized success. Such a technique is tantalizing experimentalists handling AE signal in many ways. However, training laboratory faces challenges. This study aims address few issues encountered on signal. We conduct extensive manual pickings selected...

ABSTRACT: Traditional laboratory acoustic emission (AE) source location analysis predominantly relies on P-wave arrival times, limiting the number of locatable sources due to requirement four signals for solving unknowns. This paper explores feasibility incorporating S-wave which are often otherwise discarded, into reduce fundamental from two signals. We employ a U-Net deep learning model pick times AE signals, trained using theoretical calculations based and velocities. Despite only...

ABSTRACT: Previous manual picking experiments and U-Net training have illustrated the limitations of a for laboratory acoustic emission (AE) signal processing. The overall goal this series studies is to devise an approach without excessive demand picking. In paper, we evaluate two data augmentation approaches: multiplier shifting. aims mimics weak signals, while shifting deemed physically acceptable. Our evaluations indicate that both approaches create sensitive augmented datasets current...

Waste oil-based drilling fluids are hazardous wastes containing oil, heavy-metal and organic pollutants. However, the common treatment methods at home abroad these not only waste many useful resources (because oil is discarded rather than recovered) but also increase pro-environment cost of companies. This paper develops recycling safe disposal technology from perspective utility, efficiency economy, which recycle reuse dispose rest mud fluids. The rate recovery greater 90 %, quality...

Natural earthquakes and micro-seismicity resulting from hydraulic fracturing or other engineering practices display distinctively different spatial-temporal features, like mixed burst- swarm-like features predominantly features. The mechanism(s) contributing to such observations can be diverse. We present the inspections on dynamic formation process of single tree in laboratory acoustic emission (AE) catalogs. Such largest trees contain > 97% AE events entire catalog within a test; all...

ABSTRACT: We performed a study of ultrasonic velocity as function stress and path using axial radial P S-waves. Young's modulus Poisson's ratio are calculated these velocities along directions. Static elastic moduli also measured the same protocol. Effects pre-existing microcracks in sample hypothesized via directional observations changes differential mean stress. Dynamic is observed to increase primarily stress, whereas static mainly dependent on Since dynamic reliant accuracy manually...