Based on a new elastic clump model, a flexible membrane is proposed for the discrete element numerical simulations of triaxial tests. Conversional triaxial tests of sandstone under the confining pressures of 2 MPa and 8 MPa were carried out, in order to validate the effectiveness of the proposed numerical simulation method. The numerical model is validated by comparing the numerical results with the test results. The deformation and failure process of numerical model is analyzed by stress-strain curves, micro fractures, displacement fields, stress fields and energy fields. The model shows an X-shape shear failure zone, of which the angle is very close to that of the test; the dip angle of most shear fractures is close to the angle of the internal friction; and there is a large amount of slipping frictional heat generated on the failure surface. During the loading process, the stress chain and stress concentration appear in the middle of the model, which lead to displacement zoning in the model. The failure of the model is associated with the growth of the micro tensile- and shear fractures. This study provides an effective tool for the macro-micro investigation of rock failure processes.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7910309 | PMC |
| http://dx.doi.org/10.1038/s41598-021-84224-7 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Workday Habits and Fatigue of American Jockeys.
J Occup Environ Med
December 2024
Sports Medicine Research Institute, College of Health Sciences, University of Kentucky.
Objective: 1) Characterize the workday habits of American jockeys, and 2) Evaluate the relationship between workday habits and fatigue through changes in postural stability (balance) across their workday.
Methods: Thirty-seven jockeys participated in pre- and post-race day testing. Jockeys completed questionnaires on workday habits and a two-minute balance test with tri-axial accelerometers on the unstable surface and sacrum.
A deep understanding of the mechanical properties of weakly cemented sandstones in coal-bearing strata is crucial for ensuring the safety of coal mining operations. This study addresses this problem by investigating the deformation characteristics of such rocks through triaxial compression tests, and a novel piecewise constitutive model was developed, integrating the Double-strain Hoek model (TPHM) and statistical damage theory. The outcomes highlight several key findings: (1) The experiments revealed a distinct compaction stage in weakly cemented sandstone, which becomes shorter with an increase in confining pressure, highlighting a significant mechanical property of these rocks.
View Article and Find Full Text PDFAnalysis on characteristics and mechanism for rock fracture in deep rock with cracks under dynamic-static coupling effect.
Sci Rep
December 2024
School of Civil Engineering and Architecture, Anhui University of Science and Technology, Huainan, 232001, Anhui, China.
The mechanical behavior and fracture mechanisms of deep fractured rocks under explosive dynamic loads are critical for understanding rock instability in engineering applications such as blasting operations. This study aims to investigate how the presence of pre-existing cracks and different stress states affect the mechanical properties and fracture patterns of rock-like specimens under dynamic loading conditions. We utilized a Split Hopkinson Pressure Bar (SHPB) with an active confining pressure loading device to conduct impact compression tests on rock-like specimens containing pre-existing cracks.
View Article and Find Full Text PDFTo address the challenges of performing in-situ tests on riverbed overburden gravel, this study employs three scaling methods-equal mass substitution, similar gradation, and the mixed method-to investigate the original gradation of the gravel. Large-scale triaxial consolidated drained shear tests were conducted to evaluate the effects of the maximum particle size reduction ratio (M) and confining pressure on the stress-strain behavior, fractal dimension, particle breakage, and the parameters of the Duncan-Chang model (an elastic model describing nonlinear stress-strain relationships). The study explores how scaling, based on fractal dimension and particle breakage rate, impacts the strength and deformation characteristics of gravel materials.
View Article and Find Full Text PDFExtended Reality Gaming for Exercise and Mindfulness Throughout Pediatric Cancer Rehabilitation: Protocol for a Randomized Controlled Trial.
JMIR Res Protoc
December 2024
Division of Pediatric Hematology-Oncology, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, United States.
Background: Pediatric patients with cancer have limited options to self-manage their health while they are undergoing treatments in the hospital and after they are discharged to their homes. Extended reality (ER) using head-mounted displays has emerged as an immersive method of improving pain and mental health and promoting health-enhancing physical activity among a variety of clinical groups, but there is currently no established protocol for improving both physical and mental health in pediatric cancer rehabilitation.
Objective: This phase I, pilot, feasibility randomized controlled trial aims to investigate the potential effects of a 14-week ER program on physical activity participation and indicators of health among pediatric patients with cancer who undergo bone marrow transplantation.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!