This paper introduces a new-developed mine fire-resistant optical fiber cable (OFC)KL5004,its structural characteristics, main feature, the theory about fire resistance and its application in high output and efficienc...This paper introduces a new-developed mine fire-resistant optical fiber cable (OFC)KL5004,its structural characteristics, main feature, the theory about fire resistance and its application in high output and efficiency mine.展开更多
The actively heated fiber-optic(AHFO)technology has emerged as a frontier and hotspot in soil water content measurement,offering advantages such as easy installation,large-scale distributed measurement capability,and ...The actively heated fiber-optic(AHFO)technology has emerged as a frontier and hotspot in soil water content measurement,offering advantages such as easy installation,large-scale distributed measurement capability,and resistance to electromagnetic interference.However,current AHFO water content sensors fail to simultaneously achieve high precision,applicability for deep soil,and automated real-time monitoring,thereby limiting their development and application.Therefore,this study introduces a novel actively heated fiber Bragg grating(AH-FBG)cable.Laboratory tests were conducted to assess the heating uniformity of the AH-FBG cable and to establish the temperature characteristic value(T_(t))-soil water content(θ)calibration formula for water content measurement.Subsequently,AH-FBG cables were deployed for in situ soil water content monitoring in a test pit on the Loess Plateau.Through two-year monitoring data verified the accuracy of the AH-FBG cable and elucidated the spatiotemporal distribution of in situ loess water content.Laboratory results demonstrated superior heating uniformity of AHFBG cable,with a T_(t) standard deviation of approximately 0.3℃.In the field,the AH-FBG cable exhibited excellent performance in soil water content measurement,achieving a high accuracy of 0.023 cm^(3)/cm^(3).Further analysis revealed that the θ fluctuation predominantly occurred within a 10 m depth from the soil surface,with an overall upward trend over the two-year monitoring period;the response of shallow θ to precipitation was significant but exhibited increasing hysteresis with depth;frequent precipitation significantly enhanced water infiltration depth.This study provides technical guidance for highprecision,quasi-distributed,automated and real-time water content measurement of deep soil.展开更多
The use of carbon-fiber heating cables(CFHC)to achieve effective melting of snow and ice deposited on roads is a method used worldwide.In this study,tensile and compressive tests have been conducted to analyze the mech...The use of carbon-fiber heating cables(CFHC)to achieve effective melting of snow and ice deposited on roads is a method used worldwide.In this study,tensile and compressive tests have been conducted to analyze the mechan-ical properties of the CFHC and assess whether the maximum tensile and compressive strengths can meet the pavement design specifications.In order to study the aging produced by multiple cycles of heating and cooling,in particular,the CFHC was repeatedly heated in a cold chamber with an ambient temperature ranging between-20℃ and+40℃.Moreover,to evaluate how the strength of the pavement is affected by its presence,the CFHC was embedded at different depths and concrete blocks with different curing ages were subjected to relevant com-pression and splitting tensile tests.Numerical simulations based on the ANSYS software have also been performed and compared with the outcomes of the static loading tests.The results show that the CFHC embedded in the concrete does not affect the compressive splitting tensile strengths of the pavement.Overall,the CFHC meets the conditions required for continued use in road ice melting applications.展开更多
With the development of high speed railway traffic, the structure health monitoring for high-speed rail is necessary due to the safety issue. Optical fiber sensing technology is one of the options to solve it. Stress ...With the development of high speed railway traffic, the structure health monitoring for high-speed rail is necessary due to the safety issue. Optical fiber sensing technology is one of the options to solve it. Stress vector information is the important index to make more reasonable judgments about railway safety. However, information sensed by lots of commercial optical sensors is scalar. According to the stress filed distribution of rail, this paper proposes a new type of stress vector sensor based on optical fiber sensing cable(OFSC) with a symmetrical seven optical fibers structure and analyzes the relations between angle resolution and distance between adjacent of optical fibers through finite-element software(ANSYS) simulation. Through reasonable distance configuration, the angle resolution of the OFSC can be improved, and thus stress vector information, including the stress magnitude and the angle of stress, can be more accurately obtained. The simulation results are helpful to configure OFSC for angle resolution improvement in actual practice, and increase the safety factor in high speed railway structure health monitoring.展开更多
The feasibility of longer spans relies on the successful implementation of new high-strength light weight materials such as carbon fiber reinforced polymer(CFRP). First, a dimensionless equilibrium equation and the co...The feasibility of longer spans relies on the successful implementation of new high-strength light weight materials such as carbon fiber reinforced polymer(CFRP). First, a dimensionless equilibrium equation and the corresponding compatibility equation are established to develop the cable force equation and cable displacement governing equation for suspension cables, respectively. Subsequently, the inextensible cable case is introduced. The formula of the Irvine parameter is considered and its physical interpretation as well as its relationship with the chord gravity stiffness is presented. The influences on the increment of cable force and displacement by λ2 and load ratio p′ are analyzed, respectively. Based on these assumptions and the analytical formulations, a 2000 m span suspension cable is utilized as an example to verify the proposed formulation and the responses of the relative increment of cable force and cable displacement under symmetrical and asymmetrical loads are studied and presented. In each case, the deflections resulting from elastic elongation or solely due to geometrical displacement are analyzed for the lower elastic modulus CFRP. Finally, in comparison with steel cables, the influences on the cable force equation and the governing displacement equation by span and rise span ratio are analyzed. Moreover, the influences on the static performance of suspension bridge by span and sag ratios are also analyzed. The substantive characteristics of the static performance of super span CFRP suspension bridges are clarified and the superiority and the characteristics of CFRP cable structure are demonstrated analytically.展开更多
Rising sea levels and climate change are reshaping coastal landscapes,exacerbating erosion,and increasing flood frequency,posing serious threats to the ecological balance,economic growth,and the livelihoods of coastal...Rising sea levels and climate change are reshaping coastal landscapes,exacerbating erosion,and increasing flood frequency,posing serious threats to the ecological balance,economic growth,and the livelihoods of coastal city residents[1].This necessitates advanced monitoring to mitigate climate impacts and strengthen coastal resilience.While geophysical methods for first-order coastal properties monitoring have gained traction in academia[2,3],traditional monitoring techniques are limited by sparse and unevenly distributed observation stations,failing to meet the needs for detailed regional monitoring.Moreover,the complex social and cultural environments of coastal cities challenge sustained and intensive monitoring efforts.展开更多
To gain understanding of the applicability of carbon fiber reinforced polymer (CFRP) cable in cable-supported bridges, based on the Runyang Bridge and Jinsha Bridge, a suspension bridge using CFRP cables and a cable-s...To gain understanding of the applicability of carbon fiber reinforced polymer (CFRP) cable in cable-supported bridges, based on the Runyang Bridge and Jinsha Bridge, a suspension bridge using CFRP cables and a cable-stayed bridge using CFRP stay cables are designed, in which the cable’s cross-sectional area is determined by the principle of equivalent axial stiffness. Numerical investigations on the aerodynamic stability of the two bridges are conducted by 3D nonlinear aerodynamic stability analysis. The results showed that as CFRP cables are used in cable-supported bridges, for suspension bridge, its aerodynamic stability is superior to that of the case using steel cables due to the great increase of the torsional frequency; for cable-stayed bridge, its aerodynamic stability is basically the same as that of the case using steel stay cables. Therefore as far as the wind stability is considered, the use of CFRP cables in cable-supported bridges is feasible, and the cable’s cross-sectional area should be deter-mined by the principle of equivalent axial stiffness.展开更多
A dynamic model for an inclined carbon ?ber reinforced polymer(CFRP)cable is established, and the linear and nonlinear dynamic behaviors are investigated in detail. The partial differential equations for both the in-p...A dynamic model for an inclined carbon ?ber reinforced polymer(CFRP)cable is established, and the linear and nonlinear dynamic behaviors are investigated in detail. The partial differential equations for both the in-plane and out-of-plane dynamics of the inclined CFRP cable are obtained by Hamilton's principle. The linear eigenvalues are explored theoretically. Then, the ordinary differential equations for analyzing the dynamic behaviors are obtained by the Galerkin integral and dimensionless treatments.The steady-state solutions of the nonlinear equations are obtained by the multiple scale method(MSM) and the Newton-Raphson method. The frequency-and force-response curves are used to investigate the dynamic behaviors of the inclined CFRP cable under simultaneous internal(between the lowest in-plane and out-of-plane modes) and external resonances, i.e., the primary resonances induced by the excitations of the in-plane mode,the out-of-plane mode, and both the in-plane mode and the out-of-plane mode, respectively. The effects of the key parameters, e.g., Young's modulus, the excitation amplitude,and the frequency on the dynamic behaviors, are discussed in detail. Some interesting phenomena and results are observed and concluded.展开更多
All-dielectric self-supporting(ADSS) cables are installed along with transmission line for the purpose of communication.During installation the outer layer of the cable is hydrophobic and is not prone to dry band arci...All-dielectric self-supporting(ADSS) cables are installed along with transmission line for the purpose of communication.During installation the outer layer of the cable is hydrophobic and is not prone to dry band arcing. These cables become less hydrophobic over time and become vulnerable to dry band arcing.This loss in hydrophobicity is because of the contamination formed on the outer layer due to pollution.This is one of the reasons which cause cable failure.Considerable amount of losses will be incurred on the occurrence of a cable failure as the cables are also leased to other companies.An improved equivalent circuit is used to calculate the voltage and current distribution of the double circuit line.A three-phase single circuit line and a three-phase double circuit line are used to calculate their corresponding voltage distribution and current distribution.The results could be used to predict dry band arcing on similar models.The method used considers sag,span and pollution on ADSS cable.展开更多
Novel small Raman gain measurement method for installed fiber optic cables using a modulated pump light is proposed. We have demonstrated accurate Raman gain measurement in small Raman gain less than 1dB and we also m...Novel small Raman gain measurement method for installed fiber optic cables using a modulated pump light is proposed. We have demonstrated accurate Raman gain measurement in small Raman gain less than 1dB and we also measured Raman gain for the installed fiber optic cable by using average pumping power of about only 25mW.展开更多
Acknowledgments Thanks for assistance and support, which is provided by State Grid Corporation of China and State Grid Communication Information ＆ Telecommunication Company, for the project in the process of researc...Acknowledgments Thanks for assistance and support, which is provided by State Grid Corporation of China and State Grid Communication Information ＆ Telecommunication Company, for the project in the process of research and development. Fibrlink Communications Co., Ltd will keep exerting itself to innovating, which aims for making more contribution of the smart grid on energy reduction and environment protection.展开更多
It is necessary to study dynamic operation efficiency of transmission networks in order to realize high intensification of communication networks. The operation efficiency discussed here should exist not only in logic...It is necessary to study dynamic operation efficiency of transmission networks in order to realize high intensification of communication networks. The operation efficiency discussed here should exist not only in logic-circuit layer, but also in both path layer and medium layer. A theoretical method of the measurement of layers and comprehensive evaluations is presented based on the concept of transmission efficiency.展开更多
文摘This paper introduces a new-developed mine fire-resistant optical fiber cable (OFC)KL5004,its structural characteristics, main feature, the theory about fire resistance and its application in high output and efficiency mine.
基金supported by the National Natural Science Foundation of China(Grant Nos.42307189 and 42030701)the China Postdoctoral Science Foundation(Grant No.2023M740974).
文摘The actively heated fiber-optic(AHFO)technology has emerged as a frontier and hotspot in soil water content measurement,offering advantages such as easy installation,large-scale distributed measurement capability,and resistance to electromagnetic interference.However,current AHFO water content sensors fail to simultaneously achieve high precision,applicability for deep soil,and automated real-time monitoring,thereby limiting their development and application.Therefore,this study introduces a novel actively heated fiber Bragg grating(AH-FBG)cable.Laboratory tests were conducted to assess the heating uniformity of the AH-FBG cable and to establish the temperature characteristic value(T_(t))-soil water content(θ)calibration formula for water content measurement.Subsequently,AH-FBG cables were deployed for in situ soil water content monitoring in a test pit on the Loess Plateau.Through two-year monitoring data verified the accuracy of the AH-FBG cable and elucidated the spatiotemporal distribution of in situ loess water content.Laboratory results demonstrated superior heating uniformity of AHFBG cable,with a T_(t) standard deviation of approximately 0.3℃.In the field,the AH-FBG cable exhibited excellent performance in soil water content measurement,achieving a high accuracy of 0.023 cm^(3)/cm^(3).Further analysis revealed that the θ fluctuation predominantly occurred within a 10 m depth from the soil surface,with an overall upward trend over the two-year monitoring period;the response of shallow θ to precipitation was significant but exhibited increasing hysteresis with depth;frequent precipitation significantly enhanced water infiltration depth.This study provides technical guidance for highprecision,quasi-distributed,automated and real-time water content measurement of deep soil.
基金The authors have received financial support from the National Natural Science Foundation of China(No.52078194)the Key Research and Development Program of Hubei Province(No.2021BGD015)the Knowledge Innovation Project of Wuhan(No.2022010801010259).
文摘The use of carbon-fiber heating cables(CFHC)to achieve effective melting of snow and ice deposited on roads is a method used worldwide.In this study,tensile and compressive tests have been conducted to analyze the mechan-ical properties of the CFHC and assess whether the maximum tensile and compressive strengths can meet the pavement design specifications.In order to study the aging produced by multiple cycles of heating and cooling,in particular,the CFHC was repeatedly heated in a cold chamber with an ambient temperature ranging between-20℃ and+40℃.Moreover,to evaluate how the strength of the pavement is affected by its presence,the CFHC was embedded at different depths and concrete blocks with different curing ages were subjected to relevant com-pression and splitting tensile tests.Numerical simulations based on the ANSYS software have also been performed and compared with the outcomes of the static loading tests.The results show that the CFHC embedded in the concrete does not affect the compressive splitting tensile strengths of the pavement.Overall,the CFHC meets the conditions required for continued use in road ice melting applications.
文摘With the development of high speed railway traffic, the structure health monitoring for high-speed rail is necessary due to the safety issue. Optical fiber sensing technology is one of the options to solve it. Stress vector information is the important index to make more reasonable judgments about railway safety. However, information sensed by lots of commercial optical sensors is scalar. According to the stress filed distribution of rail, this paper proposes a new type of stress vector sensor based on optical fiber sensing cable(OFSC) with a symmetrical seven optical fibers structure and analyzes the relations between angle resolution and distance between adjacent of optical fibers through finite-element software(ANSYS) simulation. Through reasonable distance configuration, the angle resolution of the OFSC can be improved, and thus stress vector information, including the stress magnitude and the angle of stress, can be more accurately obtained. The simulation results are helpful to configure OFSC for angle resolution improvement in actual practice, and increase the safety factor in high speed railway structure health monitoring.
基金Project(2010-K2-8)supported by Science and Technology Program of the Ministry of Housing and Urban Rural Development,ChinaProject supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘The feasibility of longer spans relies on the successful implementation of new high-strength light weight materials such as carbon fiber reinforced polymer(CFRP). First, a dimensionless equilibrium equation and the corresponding compatibility equation are established to develop the cable force equation and cable displacement governing equation for suspension cables, respectively. Subsequently, the inextensible cable case is introduced. The formula of the Irvine parameter is considered and its physical interpretation as well as its relationship with the chord gravity stiffness is presented. The influences on the increment of cable force and displacement by λ2 and load ratio p′ are analyzed, respectively. Based on these assumptions and the analytical formulations, a 2000 m span suspension cable is utilized as an example to verify the proposed formulation and the responses of the relative increment of cable force and cable displacement under symmetrical and asymmetrical loads are studied and presented. In each case, the deflections resulting from elastic elongation or solely due to geometrical displacement are analyzed for the lower elastic modulus CFRP. Finally, in comparison with steel cables, the influences on the cable force equation and the governing displacement equation by span and rise span ratio are analyzed. Moreover, the influences on the static performance of suspension bridge by span and sag ratios are also analyzed. The substantive characteristics of the static performance of super span CFRP suspension bridges are clarified and the superiority and the characteristics of CFRP cable structure are demonstrated analytically.
基金supported by scientific grants from Zhejiang University(2023QZJH07)。
文摘Rising sea levels and climate change are reshaping coastal landscapes,exacerbating erosion,and increasing flood frequency,posing serious threats to the ecological balance,economic growth,and the livelihoods of coastal city residents[1].This necessitates advanced monitoring to mitigate climate impacts and strengthen coastal resilience.While geophysical methods for first-order coastal properties monitoring have gained traction in academia[2,3],traditional monitoring techniques are limited by sparse and unevenly distributed observation stations,failing to meet the needs for detailed regional monitoring.Moreover,the complex social and cultural environments of coastal cities challenge sustained and intensive monitoring efforts.
基金Project (No. 502118) supported by the Natural Science Foundation of Zhejiang Province, China
文摘To gain understanding of the applicability of carbon fiber reinforced polymer (CFRP) cable in cable-supported bridges, based on the Runyang Bridge and Jinsha Bridge, a suspension bridge using CFRP cables and a cable-stayed bridge using CFRP stay cables are designed, in which the cable’s cross-sectional area is determined by the principle of equivalent axial stiffness. Numerical investigations on the aerodynamic stability of the two bridges are conducted by 3D nonlinear aerodynamic stability analysis. The results showed that as CFRP cables are used in cable-supported bridges, for suspension bridge, its aerodynamic stability is superior to that of the case using steel cables due to the great increase of the torsional frequency; for cable-stayed bridge, its aerodynamic stability is basically the same as that of the case using steel stay cables. Therefore as far as the wind stability is considered, the use of CFRP cables in cable-supported bridges is feasible, and the cable’s cross-sectional area should be deter-mined by the principle of equivalent axial stiffness.
基金Project supported by the National Natural Science Foundation of China(Nos.11572117 and 11502076)
文摘A dynamic model for an inclined carbon ?ber reinforced polymer(CFRP)cable is established, and the linear and nonlinear dynamic behaviors are investigated in detail. The partial differential equations for both the in-plane and out-of-plane dynamics of the inclined CFRP cable are obtained by Hamilton's principle. The linear eigenvalues are explored theoretically. Then, the ordinary differential equations for analyzing the dynamic behaviors are obtained by the Galerkin integral and dimensionless treatments.The steady-state solutions of the nonlinear equations are obtained by the multiple scale method(MSM) and the Newton-Raphson method. The frequency-and force-response curves are used to investigate the dynamic behaviors of the inclined CFRP cable under simultaneous internal(between the lowest in-plane and out-of-plane modes) and external resonances, i.e., the primary resonances induced by the excitations of the in-plane mode,the out-of-plane mode, and both the in-plane mode and the out-of-plane mode, respectively. The effects of the key parameters, e.g., Young's modulus, the excitation amplitude,and the frequency on the dynamic behaviors, are discussed in detail. Some interesting phenomena and results are observed and concluded.
文摘All-dielectric self-supporting(ADSS) cables are installed along with transmission line for the purpose of communication.During installation the outer layer of the cable is hydrophobic and is not prone to dry band arcing. These cables become less hydrophobic over time and become vulnerable to dry band arcing.This loss in hydrophobicity is because of the contamination formed on the outer layer due to pollution.This is one of the reasons which cause cable failure.Considerable amount of losses will be incurred on the occurrence of a cable failure as the cables are also leased to other companies.An improved equivalent circuit is used to calculate the voltage and current distribution of the double circuit line.A three-phase single circuit line and a three-phase double circuit line are used to calculate their corresponding voltage distribution and current distribution.The results could be used to predict dry band arcing on similar models.The method used considers sag,span and pollution on ADSS cable.
文摘Novel small Raman gain measurement method for installed fiber optic cables using a modulated pump light is proposed. We have demonstrated accurate Raman gain measurement in small Raman gain less than 1dB and we also measured Raman gain for the installed fiber optic cable by using average pumping power of about only 25mW.
文摘Acknowledgments Thanks for assistance and support, which is provided by State Grid Corporation of China and State Grid Communication Information ＆ Telecommunication Company, for the project in the process of research and development. Fibrlink Communications Co., Ltd will keep exerting itself to innovating, which aims for making more contribution of the smart grid on energy reduction and environment protection.
文摘It is necessary to study dynamic operation efficiency of transmission networks in order to realize high intensification of communication networks. The operation efficiency discussed here should exist not only in logic-circuit layer, but also in both path layer and medium layer. A theoretical method of the measurement of layers and comprehensive evaluations is presented based on the concept of transmission efficiency.
