Article
Engineering, Mechanical
Chenlin Liu, Weibin Wang, Tao Suo, Zhongbin Tang, Yazhou Guo, Yulong Li
Summary: This paper introduces a Combined Tension-Torsion Split Hopkinson Bar system that can load specimens synchronously under high strain rates. The system utilizes electromagnetic energy conversion technique and a new Electromagnetic-release Split Hopkinson Torsion Bar system to achieve precise control and generation of stress pulses.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2022)
Article
Construction & Building Technology
Kyoung-Min Kim, Sangho Lee, Yongjae Yu, Jae-Yeol Cho
Summary: Dynamic increase factors (DIF) of concrete compressive strength have been proposed, but without considering the effect of coarse aggregate size. This study conducted experiments and numerical analysis to investigate the effect of maximum coarse aggregate size (Gmax) on DIF. The results showed that Gmax affected the dispersion of apparent DIF and values of pure rate DIF. Based on these findings, a guideline for fabricating specimens considering Gmax for concrete SHPB tests was suggested.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Kavita Ganorkar, M. D. Goel, Tanusree Chakraborty
Summary: Basalt fiber-reinforced concrete (BFRC) was dynamically characterized using a split Hopkinson pressure bar (SHPB), showing an increase in concrete strength with increasing strain rates. The dynamic increase factor (DIF) was found to range from 0.91 to 3.58 at different strain rates.
JOURNAL OF MATERIALS IN CIVIL ENGINEERING
(2021)
Article
Materials Science, Multidisciplinary
Pascal Ruthnick, Noah Ledford, Mathieu Imbert, Michael May
Summary: The mechanical response of multi-material single-lap joints in the high-rate loading regime was measured using a split Hopkinson tension bar (SHTB). The research identified a rate dependency of the mechanical behavior of these joints and demonstrated that high-quality high-rate tests can be achieved by employing an SHTB.
Article
Engineering, Civil
Sunita Mishra, Anuradha Khetwal, Tanusree Chakraborty, Dipanjan Basu
Summary: Split Hopkinson pressure bar tests were conducted on Himalayan phyllite rock to investigate its high-strain-rate behavior. The study found that the phyllite response is strongly influenced by the dimensions of the specimens and the loading characteristics of the SHPB device. The calibrated strain rate-dependent Johnson-Holmquist constitutive model parameters were used to analyze the response of a tunnel subjected to a blast load in phyllite rock, revealing significant differences compared to the mean stress and vertical displacement.
ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING
(2022)
Article
Energy & Fuels
Geli Zhao, Xing Li, Ying Xu, Kaiwen Xia
Summary: This study developed a novel experimental system to determine the dynamic compressive response of deep rocks, and validated the system using green sandstone. The experimental results showed that the dynamic compressive strength of the rocks is influenced by loading rate, confining pressure, and pore pressure. The most common dynamic failure modes were single shear failure and X-type conjugate shear failure. The friction angle remained constant while the cohesion depended on the loading rate. Water had a bidirectional effect on dynamic strength, facilitating crack propagation but also impeding pore structure damage.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2022)
Article
Construction & Building Technology
Nao Lv, Haibo Wang, Kai Rong, Zhanyang Chen, Qi Zong
Summary: By comparing the HBB system and the SHPB system in stress wave propagation, this study found that the HBB system can effectively reduce lateral dispersion and maintain waveform, while the large diameter SHPB system has the opposite effect. The results suggest that the HBB system is capable of dynamic mechanical property testing of concrete-like materials and provides more detailed information on local mechanical properties of concrete.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Engineering, Mechanical
Lena Leicht, Tomas Fila, Petr Maca, Manfred Curbach
Summary: This paper presents an innovative technique for measuring the bond stress-slip relationships during dynamic pull-out using a tensile split Hopkinson bar and a near-to-full-scale beam-end specimen. The complex wave propagation behavior during impact is characterized and two methods for separating the longitudinal stress waves are employed. The method is considered suitable for evaluating the dynamic bond stress-slip relationship.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2023)
Article
Polymer Science
Xintao Zhu, Xiaojing Zhang, Wenjin Yao, Wenbin Li
Summary: Using a split-Hopkinson pressure bar test instrument with temperature control, this study tested the dynamic mechanical properties of silicone rubber at different temperatures and strain rates. The results showed that silicone rubber is sensitive to both strain rate and temperature, with the yield strength increasing with higher strain rates and showing temperature sensitivity at higher rates.
Article
Engineering, Mechanical
Yifei Meng, Yuting Yang, Weibin Wang, Qingbo Dou, Tao Suo
Summary: An improved high-temperature dynamic torsion experimental method was developed in this study, utilizing an electromagnetic torsional Hopkinson bar equipped with a special system and proposing a double-flange thin-walled tubular specimen, achieving online heating and synchronous assembly successfully. This provides a new approach for studying the shear mechanical properties of materials under high strain rates and high temperatures.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2022)
Article
Engineering, Mechanical
Yifei Meng, Yuting Yang, Weibin Wang, Qingbo Dou, Tao Suo
Summary: This study developed an improved high-temperature dynamic torsion experimental method for determining the shear mechanical properties of materials under the coupling effect of high strain rates and high temperatures. By optimizing the specimen design and strain measurement correction method, the accuracy and reliability of the tests were improved. Experimental results demonstrated the suitability of this method for strain rate testing at different temperatures.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2022)
Article
Chemistry, Physical
Georg Baumann, Dominik Niederkofler, Christian Ellersdorfer, Florian Feist
Summary: The study demonstrates that the designed release mechanism leads to sufficiently short and reproducible pulse rising times for both tension and compression waves, allowing for dynamic mechanical characterization of high strength steel materials.
Article
Geosciences, Multidisciplinary
Zhoujie Gu, Rongxi Shen, Zhentang Liu, Enlai Zhao, Hailiang Chen, Zichen Yuan, Xiaomeng Chu, Jiawei Tian
Summary: Dynamic failure experiments were conducted on coal samples under dynamic load in a triaxial Split-Hopkinson pressure bar test system to study the dynamic characteristics of coal in a multi-axial pre-stress state. The experiments showed that the 3D pre-stress state significantly affects the dynamic failure of coal. The dynamic initial stress of coal increases linearly with strain, then grows at a reduced rate until the peak strength, and the mechanical curve rebounds notably. The dynamic strength factors of coal vary significantly with the increase of confining pressure.
NATURAL RESOURCES RESEARCH
(2023)
Article
Engineering, Mechanical
Bagus Budiwantoro, Muhammad A. Kariem, Burhan Febrinawarta
Summary: This study compares different shear angles and recommends using a shear angle of approximately 5 degrees to achieve the purest shear loading. The flow stress variation among the tests is relatively acceptable, within +/-16.4%.
INTERNATIONAL JOURNAL OF IMPACT ENGINEERING
(2021)
Article
Computer Science, Software Engineering
Tzvi Gershanik, Itay Levin, Daniel Rittel
Summary: 2BarG is a Python-based program that analyzes Split Hopkinson Pressure Bar experiments. It features automatic signal identification and a user-friendly interface, allowing for fast, simple, and efficient data processing.
Article
Mathematics
Longjun Dong, Lingyun Zhang, Huini Liu, Kun Du, Xiling Liu
Summary: The b value of acoustic emission is an important parameter for predicting rock fractures. This study analyzed the changes in b value during rock failure and investigated the characteristics of acoustic emission events. The results showed that b value calculated using the average amplitude had higher accuracy, and an interval of event counts of 200 was suggested for b value calculations. The study also found that the b value decreased before fracture and decreased with increasing confining pressure.
Article
Engineering, Geological
Longjun Dong, Longbin Yang, Yongchao Chen
Summary: Microseismic/acoustic emission (MS/AE) location technology is a powerful means to study the spatial evolution characteristics of rock fracture and early warning of geological hazards. This study used the velocity-free MS/AE source location method to investigate the variation in MS/AE location accuracy and the spatial evolution characteristics of granite fracture under complex stress conditions. The results showed that the variation of wave velocity caused by granite fracture is a key factor for the variation of location accuracy. The study also found consistency and difference in the evolution process and results of granite microcracks under uniaxial and biaxial stress conditions.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Engineering, Geological
Lei Weng, Zhijun Wu, Zhaofei Chu, Haifeng Lu, Xiangyu Xu, Quansheng Liu
Summary: The frost damage behaviors of rock mass are influenced by its water content. This study investigates the effects of saturation degree on the evolution of unfrozen water content and the critical degree of saturation of rock mass. Experimental results show that the sandstone with lower saturation exhibits slower freezing speed and higher residual unfrozen water content. The critical degree of saturation for the studied sandstone is determined to be 50%. These findings provide valuable guidance for the prevention of freeze-thaw damage in rock masses in cold regions.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Computer Science, Interdisciplinary Applications
Zhijun Wu, Wenjun Cui, Lei Weng, Quansheng Liu
Summary: This study develops a coupled thermal-hydraulic-mechanical (THM) formulation based on the 2D combined finite-discrete element method (FDEM) to investigate the rock deformation and fracturing behavior. The formulation consists of three subsolvers for hydraulic, thermal, and mechanical properties, and is verified through benchmark problems. The results demonstrate the potential of the numerical tool in modeling THM process-driven deformation and fracturing of rock mass.
COMPUTERS AND GEOTECHNICS
(2022)
Article
Engineering, Geological
Zhiyang Wang, Zhijun Wu, Zhaofei Chu, Lei Weng, Yang Liu, Quansheng Liu
Summary: This paper investigates the effect of grouting on the micro-cracking mechanism in sandstone specimens. The results show that grouting induces more microcracks, especially shear microcracks, before failure occurs. The influence of grouting on microcrack initiation varies with the oblique angle of the flaw. For certain angles, grouting enhances the shear microcrack and changes the failure mode to shear mode.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2022)
Article
Engineering, Geological
Zhijun Wu, Wenjun Cui, Lei Weng, Quansheng Liu
Summary: One controversial issue associated with enhanced geothermal systems is induced seismicity. This study investigates the triggering mechanisms of potential fault activation during geothermal heat extraction and finds that thermal effects play a crucial role in controlling fault slip behavior and illuminating the triggering mechanism of unexpected seismic activities.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Engineering, Geological
Lei Weng, Zhijun Wu, Zhiyang Wang, Zhaofei Chu, Xiangyu Xu, Quansheng Liu
Summary: This study proposed a projective reconstruction method (PRM) to obtain the wave velocity model for heterogeneous rock and an improved AE source localization algorithm using the arrival time-based governing equations. The feasibility and validation of the PRM-based wave velocity model and the proposed AE source localization algorithm were verified by pencil lead break tests. The results indicate that the PRM-based AE source localization for the post-grouted samples is much more accurate than the other two models. Finally, the fracturing mechanisms of the post-grouted samples with random inclusions were illuminated based on the results of the AE source localization and moment tensor inversion.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Chemistry, Analytical
Longjun Dong, Huanyu Zhu, Fang Yan, Shuijin Bi
Summary: In this study, a rock instability risk field model using microseismic monitoring data is proposed to create effective risk management. The rock instability risk is presented visually in 3D visualization. The in-situ microseismic monitoring data is collected and analyzed to calculate peak ground velocity (PGV), peak ground acceleration (PGA), energy flux, energy, and seismic moment. The weights of PGV, PGA, and energy flux are determined using the analytic hierarchy process (AHP) to calculate risk severity. The Copula function is used to solve the joint probability distribution function of energy and seismic moment. The spatial distribution characteristics of risk are obtained by data fitting, and a three-dimensional (3D) risk field model is established. The established risk field is verified by comparing monitoring data without disturbance and blasting data with disturbance. The proposed risk field method can reasonably and accurately evaluate the regional risk of rock instability, providing a theoretical foundation for the risk prediction and management of rock instability in deep mining.
Article
Environmental Sciences
Longjun Dong, Jiachuang Wang
Summary: Intelligent Safety Ergonomics (ISE) is a new direction for safety ergonomics in the era of big data, providing a deeper understanding of human-machine-environment systems and new research methods. This research not only helps safety researchers and practitioners to correctly understand the concept of ISE, but it also injects energy and vitality into the development of safety ergonomics and cleaner production.
INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH
(2023)
Article
Mechanics
Shiming Wang, Jiaqi Wang, Xianrui Xiong, Zhongjun Ren, Lei Weng, Manoj Khandelwal, Jian Zhou
Summary: Thin Spray-On Liner (TSL) is widely used in underground engineering support like mining due to its ease of operation and effective support. A series of uniaxial compression experiments were conducted on TSL-coated specimens under static and dynamic loads to study the support effect. The results showed that the TSL improves the strength and peak strain of sandstone, with a more significant improvement observed with increased coating thickness. TSL provides good bonding ability and tensile properties to support the rock. Simulation results confirmed the experimental findings, demonstrating that TSL delays failure time and reduces cracks.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2023)
Article
Engineering, Electrical & Electronic
Longjun Dong, Shuijin Bi, Yihan Zhang, Qingchun Hu, Huanyu Zhu
Summary: A new time picking method called the wavelet-STA/LTA-AIC (WSA) picker, which combines the advantages of wavelet transform, STA/LTA method, and Akaike information criterion, is proposed in this study. The performance of the WSA picker in picking arrival times is assessed by locating both artificial sources (pencil-lead breaking on marble panel) and natural sources (tensile cracking on granite). The WSA picker shows less location error compared to the AIC picker in all experiment results.
IEEE SENSORS JOURNAL
(2023)
Article
Engineering, Geological
Mengyi Li, Zhijun Wu, Lei Weng, You Wu, Zhiyang Wang, Quansheng Liu
Summary: In this study, the tensile strengths of mineral grain interfaces (MGIs) in granite after different thermo-hydro-mechanical (THM) treatments were directly measured. The results revealed that the tensile strength of MGIs is influenced by the pore pressure and the type of interface between quartz and feldspar. Based on these findings, degradation models of MGIs' tensile strength related to THM treatments were proposed.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2023)
Article
Metallurgy & Metallurgical Engineering
Long-jun Dong, Xian-hang Yan, Jian Wang, Zheng Tang
Summary: Combining microseismic multiparameter analysis, high-magnitude microseismic event distribution, and microseismic tomography, it is possible to effectively identify hazard precursor related to rockburst in underground mining. A self-developed microseismic monitoring system was implemented in a Shaanxi underground mine in China, and a correlation model was established between velocity anomalies and mining activity regions based on tomography results. Risk areas were determined by analyzing multiple parameters, including rock fracture parameter, MS activity, tomography results, high-magnitude microseismic event distribution, and in-site survey. The results showed that microseismic information can serve as an early warning identification of hazards and has wide future applications.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2023)
Article
Computer Science, Interdisciplinary Applications
Zhaofei Chu, Zhijun Wu, Quansheng Liu, Lei Weng, Xiangyu Xu, Kui Wu, Zhenyu Sun
Summary: This paper presents a time-dependent solution for circular tunnels excavated in soft rock under high in situ stress. The solution takes into account both the process of longitudinal excavation and the sequential installation of elastic linings. By dividing the solution into two stages and considering the rheological properties of the rock, explicit expressions for tunnel convergences and support loads are derived. The proposed solution is validated through comparison with numerical results and previous solutions, and parametric studies are conducted to analyze the effects of different stages and solutions.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Construction & Building Technology
Longji Wu, Zhijun Wu, Lei Weng, Yang Liu, Quansheng Liu
Summary: This study successfully prepared a new polyacrylate latex modified cement grout that meets the requirements of water plugging and reinforcement, and exhibits excellent working performance.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
