The increasing demand for mineral resources has significantly deepened the excavation depths of open-pit mines.Large-scale deformation disasters caused by landslides on open pit mine slopes occur frequently,posing sev...The increasing demand for mineral resources has significantly deepened the excavation depths of open-pit mines.Large-scale deformation disasters caused by landslides on open pit mine slopes occur frequently,posing severe threats to human safety and mine operations.Therefore,research on monitoring and early warning technologies for openpit mine landslides is of utmost importance.The emergence of the Newtonian force monitoring and early warning system has introduced an effective new approach for landslide monitoring in open-pit mines and has been successfully applied in the Nanfen openpit mine,where it monitored landslides and issued early warnings up to 16 hours in advance.This study focuses on the bedding rock slope on the footwall of the Nanfen open pit mine,analyzing the geological conditions of the mining area.Through laboratory experiments,the mechanical parameters and mineral composition characteristics of the regional rock mass(greenschist)are obtained.A geological mechanical model of the landslide was then constructed,and the NPR anchor cable numerical analysis model was developed using FLAC3D numerical simulation software to analyze the variation patterns of Newtonian force during landslides.Based on this analysis,the influence of different NPR anchor cable parameters(including anchor cable inclination angle,spacing,and pre-tension force)on the Newtonian force was investigated.Comparative results indicate that the optimal design parameters for the NPR anchor cables are a 25°inclination angle,40 m anchoring spacing,and a 400 kN pre-tension force.Additionally,it was found that the sensitivity of these three key parameters to the Newtonian force load,from highest to lowest,is as follows:pre-tension force,spacing,and inclination angle.This optimal configuration provides practical guidance for the design of NPR anchor cables in Newtonian force monitoring applications,offering theoretical and technical support for future landslide monitoring and early warning.展开更多
In the surgery of lumbar disc herniation(LDH),the nerve root retractor is used to pull the nerve root to prevent damage.The traditional medical nerve root retractor cannot quantify the force on the nerve root.In order...In the surgery of lumbar disc herniation(LDH),the nerve root retractor is used to pull the nerve root to prevent damage.The traditional medical nerve root retractor cannot quantify the force on the nerve root.In order to improve the nerve root retractor,this paper proposes an intraoperative lumbar neurological force monitoring system.The core module of this system is the improved nerve root retractor equipped with the high density flexible pressure sensor array.The high density microneedle array and multiple pressure detection units are used in the pressure sensor to realise sensitive pressure monitoring in a narrow surgical operation area.The sensing area is 4 mm×17 mm,including 6 detection units.The sensitivity of sensor is 67.30%/N in the range of 0-5 N.This system is used for in vitro animal experiments,which can continuously detect pressure.展开更多
In the realm of slope monitoring and reinforcement,traditional prestressing anchor cables are extensively used.However,these conventional methods often face limitations when applied to loess slopes,such as potential i...In the realm of slope monitoring and reinforcement,traditional prestressing anchor cables are extensively used.However,these conventional methods often face limitations when applied to loess slopes,such as potential issues with stress concentration and insufficient adaptability to the unique mechanical properties of loess,which may lead to challenges in ensuring long-term stability and effective reinforcement.Negative Poisson's ratio(NPR)anchor cables with constant resistance have emerged as a promising alternative,which can better match the engineering demands of loess slopes by providing more uniform stress distribution and adaptive deformation characteristics.The NPR cable's ability to maintain a constant resistance during deformation offers a distinct advantage over traditional methods as it can more effectively accommodate the complex and variable conditions of loess slopes.To investigate the anchoring performance of NPR cables in loess slope,the stress characteristics of NPR cable in loess medium were simulated and analysed by ABAQUS finite element software.First,static and general quasi-static analysis methods were used to simulate the NPR cable under static tensile conditions.The consistency of the simulated constant resistance deformation characteristics with experimental results found in the literature was verified.Second,the interaction model between the NPR cable coupled with the loess medium was established.Its constant resistance was calculated to be about 24.08%larger than that of NPR anchor cable while its plastic deformation was reduced by about 37.14%.The compressive stress on the contact surface between NPR cable and loess was concentrated near the free end of the sleeve,which indicated that the loess was prone to severe damage at the free end.The research results reveal the typical shear failure mechanism of NPR cable in loess medium,which provides an important theoretical basis for prevention of landslides and monitoring of loess slopes.展开更多
With the scale extending of mining, the landslide disaster in the earth’s surface will become more and more serious, and these landslide disasters are being threatened to the sustainable safe mining of the undergroun...With the scale extending of mining, the landslide disaster in the earth’s surface will become more and more serious, and these landslide disasters are being threatened to the sustainable safe mining of the underground mine and the open-pit mine. Based on the theory that sliding force is greater than the shear resistance (resisting force) at the potential slip surface is the necessary and sufficient condition to occur the landslide as the sliding criterion, the principle and method for sliding force remote monitoring is presented, and the functional relationship between the human mechanical quantity and the natural sliding force is derived, hereby, the natural sliding force can be calculated according to the human mechanical quantity. Based on above principle and method, a new system of landslide remote monitoring is designed and 53 systems are installed on the landslide body in the Luoshan mining area, which make up the landslide remote monitoring network. According to the results of field test around 8 months, monitoring curves between sliding force and time are obtained, which can describe and forecast the develop trend of landslide. According to above analysis, the results show that this system has some following advantages: (1) real-time monitoring; (2) remote intelligent transmission; (3) landslides early warning.展开更多
A cable net structure is selected to support its reflecting triangular aluminum panels of FAST(five-hundred-meter aperture spherical radio telescope).To ensure the security and stability of the supporting structure,ca...A cable net structure is selected to support its reflecting triangular aluminum panels of FAST(five-hundred-meter aperture spherical radio telescope).To ensure the security and stability of the supporting structure,cable force of typical cables must be monitored on line.Considering the stringent requirements in installation,accuracy,long-term stability and EMI(Electromagnetic interference),most of the commonly used cable force measurement methods or sensors are not suitable for the cable force monitoring of the supporting cable-net of FAST.A method is presents to accomplish the cable force monitoring,which uses a vibrating wire strain gauge to monitor the strain of linear strain area at the anchor head.Experiments have been carried out to verify the feasibility.The method has a series of advantages,such as high reliability,high accuracy,good dynamic performance and durability,easiness of maintenance,technical maturity in industry and EMI shielding.Theoretical analysis shows that there is a linear relationship between the cable body force and anchor head surface strain,and experimental results proves a good linear relationship with excellent repeatability between the cable body force and anchor head surface strain measured by the vibrating wire strain gauge,with a linear fit better than 0.98.Mean square error in practical measuring is 2.5t.The relative error is better than 4%within the scope of the cable force in FAST operation which meets practical demand in FAST engineering.展开更多
The rapid development of flexible triboelectric nanogenerators(TENGs)has become an alternative to batteries for wearable devices.Stretchable,multifunctional,and low-cost are the primary development directions for thes...The rapid development of flexible triboelectric nanogenerators(TENGs)has become an alternative to batteries for wearable devices.Stretchable,multifunctional,and low-cost are the primary development directions for these wearable devices based on TENG.Herein,a stretchable triboelectric generator with coplanar integration was designed for energy harvesting and force sensing.The industrial conductive silicone and silicone were used to fabricate the TENG with a thickness of less than 0.9 mm.When the elongation was less than 150%,TENG exhibited excellent linear characteristics in the resistance-tensile strain correspondence,and the coefficient of determination was 0.99.This stretchable TENG with a sufficient contact area of 9 cm^(2) could generate a short-circuit current of 2μA when it was in contact with the skin.Lastly,an intelligent tension monitoring wearable device that can effectively measure the tensile force was developed.Such a stretchable,coplanar integration-based,and low-cost wearable device has excellent applicability in wearable electronics.展开更多
In order to ensure the testing range and long-term reliability of the fiber Bragg grating （FBG） used for the smart cable, a smart cable embedded with FBG strain sensors based on the desensitized encapsulation struct...In order to ensure the testing range and long-term reliability of the fiber Bragg grating （FBG） used for the smart cable, a smart cable embedded with FBG strain sensors based on the desensitized encapsulation structure was designed. For a smart cable specimen, the fatigue loading experiments with the cycle from 100 thousands to 2 million and 0.95 times nominal breaking cable force （Pb） were carried out, which tested the long-serving effects of the smart cable. The test results of the static tension loading and unloading during the stepwise fatigue cycle process showed that the encapsulated FBG strain sensors had the good linearity and repeatability. Also all sensors survived after 2 million times fatigue cycle. 0.95Pb static tension test showed that the encapsulated FBG strain sensors embedded inside the cable reached 4.5% testing accuracy in the 0.86Pb working range. After 0.95Pb static tension test, the dissection test was carried out by breaking the force tension. The results showed that the appearances of the encapsulated sensors were good, and the design structures were not changed and damaged.展开更多
基金supported by collaborative innovation center for prevention and control of mountain geological hazards of Zhejiang province(Project number:PCMGH-2022-06)。
文摘The increasing demand for mineral resources has significantly deepened the excavation depths of open-pit mines.Large-scale deformation disasters caused by landslides on open pit mine slopes occur frequently,posing severe threats to human safety and mine operations.Therefore,research on monitoring and early warning technologies for openpit mine landslides is of utmost importance.The emergence of the Newtonian force monitoring and early warning system has introduced an effective new approach for landslide monitoring in open-pit mines and has been successfully applied in the Nanfen openpit mine,where it monitored landslides and issued early warnings up to 16 hours in advance.This study focuses on the bedding rock slope on the footwall of the Nanfen open pit mine,analyzing the geological conditions of the mining area.Through laboratory experiments,the mechanical parameters and mineral composition characteristics of the regional rock mass(greenschist)are obtained.A geological mechanical model of the landslide was then constructed,and the NPR anchor cable numerical analysis model was developed using FLAC3D numerical simulation software to analyze the variation patterns of Newtonian force during landslides.Based on this analysis,the influence of different NPR anchor cable parameters(including anchor cable inclination angle,spacing,and pre-tension force)on the Newtonian force was investigated.Comparative results indicate that the optimal design parameters for the NPR anchor cables are a 25°inclination angle,40 m anchoring spacing,and a 400 kN pre-tension force.Additionally,it was found that the sensitivity of these three key parameters to the Newtonian force load,from highest to lowest,is as follows:pre-tension force,spacing,and inclination angle.This optimal configuration provides practical guidance for the design of NPR anchor cables in Newtonian force monitoring applications,offering theoretical and technical support for future landslide monitoring and early warning.
基金the National Key Technologies R&D Program(No.2016YFC0105604)the National Natural Science Foundation of China(No.61474107).
文摘In the surgery of lumbar disc herniation(LDH),the nerve root retractor is used to pull the nerve root to prevent damage.The traditional medical nerve root retractor cannot quantify the force on the nerve root.In order to improve the nerve root retractor,this paper proposes an intraoperative lumbar neurological force monitoring system.The core module of this system is the improved nerve root retractor equipped with the high density flexible pressure sensor array.The high density microneedle array and multiple pressure detection units are used in the pressure sensor to realise sensitive pressure monitoring in a narrow surgical operation area.The sensing area is 4 mm×17 mm,including 6 detection units.The sensitivity of sensor is 67.30%/N in the range of 0-5 N.This system is used for in vitro animal experiments,which can continuously detect pressure.
基金the State Key Laboratory of Deep Geotechnical Mechanics and Underground Engineering(SKLGDUEK2124)of China University of Mining and Technology(Beijing)for its support for this research。
文摘In the realm of slope monitoring and reinforcement,traditional prestressing anchor cables are extensively used.However,these conventional methods often face limitations when applied to loess slopes,such as potential issues with stress concentration and insufficient adaptability to the unique mechanical properties of loess,which may lead to challenges in ensuring long-term stability and effective reinforcement.Negative Poisson's ratio(NPR)anchor cables with constant resistance have emerged as a promising alternative,which can better match the engineering demands of loess slopes by providing more uniform stress distribution and adaptive deformation characteristics.The NPR cable's ability to maintain a constant resistance during deformation offers a distinct advantage over traditional methods as it can more effectively accommodate the complex and variable conditions of loess slopes.To investigate the anchoring performance of NPR cables in loess slope,the stress characteristics of NPR cable in loess medium were simulated and analysed by ABAQUS finite element software.First,static and general quasi-static analysis methods were used to simulate the NPR cable under static tensile conditions.The consistency of the simulated constant resistance deformation characteristics with experimental results found in the literature was verified.Second,the interaction model between the NPR cable coupled with the loess medium was established.Its constant resistance was calculated to be about 24.08%larger than that of NPR anchor cable while its plastic deformation was reduced by about 37.14%.The compressive stress on the contact surface between NPR cable and loess was concentrated near the free end of the sleeve,which indicated that the loess was prone to severe damage at the free end.The research results reveal the typical shear failure mechanism of NPR cable in loess medium,which provides an important theoretical basis for prevention of landslides and monitoring of loess slopes.
基金Project 2006CB202200 supported by the National Basic Research Program of China
文摘With the scale extending of mining, the landslide disaster in the earth’s surface will become more and more serious, and these landslide disasters are being threatened to the sustainable safe mining of the underground mine and the open-pit mine. Based on the theory that sliding force is greater than the shear resistance (resisting force) at the potential slip surface is the necessary and sufficient condition to occur the landslide as the sliding criterion, the principle and method for sliding force remote monitoring is presented, and the functional relationship between the human mechanical quantity and the natural sliding force is derived, hereby, the natural sliding force can be calculated according to the human mechanical quantity. Based on above principle and method, a new system of landslide remote monitoring is designed and 53 systems are installed on the landslide body in the Luoshan mining area, which make up the landslide remote monitoring network. According to the results of field test around 8 months, monitoring curves between sliding force and time are obtained, which can describe and forecast the develop trend of landslide. According to above analysis, the results show that this system has some following advantages: (1) real-time monitoring; (2) remote intelligent transmission; (3) landslides early warning.
基金Supported by the National Natural Science Foundation of China(No.11173035,11273036)
文摘A cable net structure is selected to support its reflecting triangular aluminum panels of FAST(five-hundred-meter aperture spherical radio telescope).To ensure the security and stability of the supporting structure,cable force of typical cables must be monitored on line.Considering the stringent requirements in installation,accuracy,long-term stability and EMI(Electromagnetic interference),most of the commonly used cable force measurement methods or sensors are not suitable for the cable force monitoring of the supporting cable-net of FAST.A method is presents to accomplish the cable force monitoring,which uses a vibrating wire strain gauge to monitor the strain of linear strain area at the anchor head.Experiments have been carried out to verify the feasibility.The method has a series of advantages,such as high reliability,high accuracy,good dynamic performance and durability,easiness of maintenance,technical maturity in industry and EMI shielding.Theoretical analysis shows that there is a linear relationship between the cable body force and anchor head surface strain,and experimental results proves a good linear relationship with excellent repeatability between the cable body force and anchor head surface strain measured by the vibrating wire strain gauge,with a linear fit better than 0.98.Mean square error in practical measuring is 2.5t.The relative error is better than 4%within the scope of the cable force in FAST operation which meets practical demand in FAST engineering.
基金supported by the National Key Research and Development Program of China(Grant No.2019YFB2004800)National Natural Science Foundation for Distinguished Young Scholars of China(Grant No.61525107)National Natural Science Foundation for China as National Major Scientific Instruments Development Project(Grant No.61727806)。
文摘The rapid development of flexible triboelectric nanogenerators(TENGs)has become an alternative to batteries for wearable devices.Stretchable,multifunctional,and low-cost are the primary development directions for these wearable devices based on TENG.Herein,a stretchable triboelectric generator with coplanar integration was designed for energy harvesting and force sensing.The industrial conductive silicone and silicone were used to fabricate the TENG with a thickness of less than 0.9 mm.When the elongation was less than 150%,TENG exhibited excellent linear characteristics in the resistance-tensile strain correspondence,and the coefficient of determination was 0.99.This stretchable TENG with a sufficient contact area of 9 cm^(2) could generate a short-circuit current of 2μA when it was in contact with the skin.Lastly,an intelligent tension monitoring wearable device that can effectively measure the tensile force was developed.Such a stretchable,coplanar integration-based,and low-cost wearable device has excellent applicability in wearable electronics.
基金The research work reported in this paper was jointly supported by the National Engineering Laboratory for Fiber Optic Sensing Technology, Wuhan University of Technology, China and FASTEN Group Company. Thanks to the support of Wuhan City Building Research Funds （201310）, the Fundamental Research Funds for the Central Universities （WUT： 2014-IV-090）, and the National Natural Science Foundation of China （Major Program： 61290310）. Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author（s） and source are credited.
文摘In order to ensure the testing range and long-term reliability of the fiber Bragg grating （FBG） used for the smart cable, a smart cable embedded with FBG strain sensors based on the desensitized encapsulation structure was designed. For a smart cable specimen, the fatigue loading experiments with the cycle from 100 thousands to 2 million and 0.95 times nominal breaking cable force （Pb） were carried out, which tested the long-serving effects of the smart cable. The test results of the static tension loading and unloading during the stepwise fatigue cycle process showed that the encapsulated FBG strain sensors had the good linearity and repeatability. Also all sensors survived after 2 million times fatigue cycle. 0.95Pb static tension test showed that the encapsulated FBG strain sensors embedded inside the cable reached 4.5% testing accuracy in the 0.86Pb working range. After 0.95Pb static tension test, the dissection test was carried out by breaking the force tension. The results showed that the appearances of the encapsulated sensors were good, and the design structures were not changed and damaged.
