The electric field intensity (EFI) is important characteristic quantity for evaluating the internal insulation state of cable joints. Based on finite element method, this paper proposes two EFI research methods, field...The electric field intensity (EFI) is important characteristic quantity for evaluating the internal insulation state of cable joints. Based on finite element method, this paper proposes two EFI research methods, field-circuit coupling method and equivalent circuit method. The average EFI of the inner surface of the outer semi-conducting shield can be calculated from the current in the measuring circuit. The relative error between these two methods is about 15%, which roughly proves the consistency of the two methods. Further practical application research enables online monitoring of cable joints.展开更多
In an integrated structure low resistance CICC joint, current is conducted by outer cable strands coming into touch with the conductive Cu sole. So it is an important condition for satisfying joint performance that ea...In an integrated structure low resistance CICC joint, current is conducted by outer cable strands coming into touch with the conductive Cu sole. So it is an important condition for satisfying joint performance that each strand of the cable inside the joint is able to come to the outermost by transposition. This paper presents analysis, calculation and figures for the strand transposition. According to the twist procedures of the superconducting cable, the author computed the actual pitch of each stage cable, consecutively computed the projection of each stage cable on the axis of the cable (z axis) and the corresponding twist angle as the z coordinate changes, which is then drawn by AutoCAD. From the results shown in the figures, the minimal cable length, which enables each strand to transpose almost equally to the outermost of the cable in such a length, call be determined as the optimal joint length.展开更多
The analysis of the impulse voltage on the internal electric field of the cable joint plays a key role in studying the breakdown of the joint. Based on the finite element method, a three-dimensional electromagnetic fi...The analysis of the impulse voltage on the internal electric field of the cable joint plays a key role in studying the breakdown of the joint. Based on the finite element method, a three-dimensional electromagnetic field simulation model of the cable joint is established in this paper. Simulation results show that the voltage at the head of the cable joint reaches about twice the impulse voltage. The increase of the conductivity of semi-conductive material also leads to the increase of electric field intensity. Then, several points and curves at different positions are selected for further analysis in this paper. Among them, the electric field distortion at the edge of the high voltage shield is the most serious and the electric field in the air gap is the least.展开更多
Virtual simulation is an economical and efficient method in mechanical system design. Numerical modeling of a spar platform, tethered by a mooring cable with a spherical joint is developed for the dynamic simulation o...Virtual simulation is an economical and efficient method in mechanical system design. Numerical modeling of a spar platform, tethered by a mooring cable with a spherical joint is developed for the dynamic simulation of the floating structure in ocean. The geometry modeling of the spar is created using finite element methods. The submerged part of the spar bears the buoyancy, hydrodynamic drag force, and effect of the added mass and Froude-Krylov force. Strip theory is used to sum up the forces acting on the elements. The geometry modeling of the cable is established based on the lumped-mass-and-spring modeling through which the cable is divided into 10 elements. A new element-fixed local frame is used, which is created by the element orientation vector and relative velocity of the fluid, to express the loads acting on the cable. The bottom of the cable is fixed on the seabed by spring forces, while the top of the cable is connected to the bottom of the spar platform by a modified spherical joint. This system suffers the propagating wave and current in the X-direction and the linear wave theory is applied for setting of the propagating wave. Based on the numerical modeling, the displacement-load relationships are analyzed, and the simulation results of the numerical modeling are compared with those by the commercial simulation code, Proteus DS. The comparison indicates that the numerical modeling of the spar platform tethered by a mooring cable is well developed, which provides an instruction for the optimization of a floating structure tethered by a mooring cable system.展开更多
To research the reinforcement effect of a rock slope with group anchorage cablesand the stress characteristics of pre-stressed anchorage cables in the fractured surface,the rock slope calculated model of a wedge block...To research the reinforcement effect of a rock slope with group anchorage cablesand the stress characteristics of pre-stressed anchorage cables in the fractured surface,the rock slope calculated model of a wedge block within the double-slide face wasestablished by using the finite difference software according to the actual slope projectcombined with indoor model test.The pre-stress loss rule of the anchorage cable andthe distribution of axial force and the force-transferring mechanism of the anchorage cablewere analyzed during simulation.Also, based on the displacement contour and thesafety factor of the calculated results, the quantitative analysis for the reinforcement effectof the rock slope with group pre-stressed anchorage cable was discovered.The resultscomputed by the software conform with the data in the experiment, which canprove the effectiveness and correctness of parameter selection and model building.展开更多
目的探讨尺骨鹰嘴骨折治疗中Cable-pin系统和克氏针张力带(tension band wiring,TBW)两种内固定方法的临床效果。方法尺骨鹰嘴骨折病人36例,根据所使用内固定种类的不同分为Cable-pin系统治疗的Cable-pin组(19例)和克氏针张力带治疗的TB...目的探讨尺骨鹰嘴骨折治疗中Cable-pin系统和克氏针张力带(tension band wiring,TBW)两种内固定方法的临床效果。方法尺骨鹰嘴骨折病人36例,根据所使用内固定种类的不同分为Cable-pin系统治疗的Cable-pin组(19例)和克氏针张力带治疗的TBW组(17例),对每组病人术中情况、远期效果及并发症发生率等情况进行比较。结果所有病人均获随访,随访时间12~25个月,平均(13.00±4.68)个月。Cable-pin组在骨折愈合时间、术后优良率及并发症发生率分别为(12.2±2.3)周、78.9%和10.5%,TBW组分别为(16.0±2.2)周,58.8%和,35.3%,两组比较差异有统计学意义(P<0.05);Cable-pin组在手术出血量、术中耗时分别为(66.4±11.0)ml和1.5±0.6)小时,TBW组分别为(71.6±9.8)ml和(1.6±0.5)小时,两组比较比较,差异无统计学意义(P>0.05)。结论治疗尺骨鹰嘴骨折时,Cable-pin系统利于骨折愈合,固定可靠及并发率低。展开更多
The conductors of both the toroidal field (TF) and poloidal field (PF) coils of EAST are NiTi cable-in-conduit conductors (CICCs). The sizes of this type of CICC are 20.3 mm×20.3 mm and 18.5 mm×18.5 mm...The conductors of both the toroidal field (TF) and poloidal field (PF) coils of EAST are NiTi cable-in-conduit conductors (CICCs). The sizes of this type of CICC are 20.3 mm×20.3 mm and 18.5 mm×18.5 mm respectively. A relevant R&D program has been carried out for three years at the Research and Manufacture Center (RMC) of the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP) to acquire the manufacturing techniques and master the behavior of the testing joints. Based on the experience gained from the manufacture and test of a sub-cable joint, three kinds of joints were made. The final design was determined after carefully evaluating their simple mechanism, good cooling line, lower AC loss and resistance, compact size, and convenience for manufacture and on-site assembly. Two steps were developed to carry out the final joint. The first step was forming the terminals' super conductors. The second step was clamping the two terminals together to ensure their good contact with the copper conductor sole. The two terminals could be connected in different directions to get two kinds of conductor connections. A hydraulic instrument was developed to impact the terminals. It could impact the terminals in high accuracy in terms of their size and shape. The cross section of the terminal was tried in circular and an elliptic shape. Five full-size joints were made according to the design and then tested. When they were tested in bathing cold condition, their resistance was from 2 nΩ to 4 nΩ The latest joint was tested in real working conditions where the resistance varied from 2 nΩ to 12 nΩ, depending on the testing current ranging from 2 kA to 10 kA.展开更多
文摘The electric field intensity (EFI) is important characteristic quantity for evaluating the internal insulation state of cable joints. Based on finite element method, this paper proposes two EFI research methods, field-circuit coupling method and equivalent circuit method. The average EFI of the inner surface of the outer semi-conducting shield can be calculated from the current in the measuring circuit. The relative error between these two methods is about 15%, which roughly proves the consistency of the two methods. Further practical application research enables online monitoring of cable joints.
文摘In an integrated structure low resistance CICC joint, current is conducted by outer cable strands coming into touch with the conductive Cu sole. So it is an important condition for satisfying joint performance that each strand of the cable inside the joint is able to come to the outermost by transposition. This paper presents analysis, calculation and figures for the strand transposition. According to the twist procedures of the superconducting cable, the author computed the actual pitch of each stage cable, consecutively computed the projection of each stage cable on the axis of the cable (z axis) and the corresponding twist angle as the z coordinate changes, which is then drawn by AutoCAD. From the results shown in the figures, the minimal cable length, which enables each strand to transpose almost equally to the outermost of the cable in such a length, call be determined as the optimal joint length.
文摘The analysis of the impulse voltage on the internal electric field of the cable joint plays a key role in studying the breakdown of the joint. Based on the finite element method, a three-dimensional electromagnetic field simulation model of the cable joint is established in this paper. Simulation results show that the voltage at the head of the cable joint reaches about twice the impulse voltage. The increase of the conductivity of semi-conductive material also leads to the increase of electric field intensity. Then, several points and curves at different positions are selected for further analysis in this paper. Among them, the electric field distortion at the edge of the high voltage shield is the most serious and the electric field in the air gap is the least.
基金Supported by Human Resources Development Program of Korea Institute of Energy Technology Evaluation and Planning(KETEP)Ministry of Trade,Industry and Energy of Korea(Grant No.20134030200290)
文摘Virtual simulation is an economical and efficient method in mechanical system design. Numerical modeling of a spar platform, tethered by a mooring cable with a spherical joint is developed for the dynamic simulation of the floating structure in ocean. The geometry modeling of the spar is created using finite element methods. The submerged part of the spar bears the buoyancy, hydrodynamic drag force, and effect of the added mass and Froude-Krylov force. Strip theory is used to sum up the forces acting on the elements. The geometry modeling of the cable is established based on the lumped-mass-and-spring modeling through which the cable is divided into 10 elements. A new element-fixed local frame is used, which is created by the element orientation vector and relative velocity of the fluid, to express the loads acting on the cable. The bottom of the cable is fixed on the seabed by spring forces, while the top of the cable is connected to the bottom of the spar platform by a modified spherical joint. This system suffers the propagating wave and current in the X-direction and the linear wave theory is applied for setting of the propagating wave. Based on the numerical modeling, the displacement-load relationships are analyzed, and the simulation results of the numerical modeling are compared with those by the commercial simulation code, Proteus DS. The comparison indicates that the numerical modeling of the spar platform tethered by a mooring cable is well developed, which provides an instruction for the optimization of a floating structure tethered by a mooring cable system.
基金Supported by the National Natural Science Foundation of China(50874085)
文摘To research the reinforcement effect of a rock slope with group anchorage cablesand the stress characteristics of pre-stressed anchorage cables in the fractured surface,the rock slope calculated model of a wedge block within the double-slide face wasestablished by using the finite difference software according to the actual slope projectcombined with indoor model test.The pre-stress loss rule of the anchorage cable andthe distribution of axial force and the force-transferring mechanism of the anchorage cablewere analyzed during simulation.Also, based on the displacement contour and thesafety factor of the calculated results, the quantitative analysis for the reinforcement effectof the rock slope with group pre-stressed anchorage cable was discovered.The resultscomputed by the software conform with the data in the experiment, which canprove the effectiveness and correctness of parameter selection and model building.
文摘目的探讨尺骨鹰嘴骨折治疗中Cable-pin系统和克氏针张力带(tension band wiring,TBW)两种内固定方法的临床效果。方法尺骨鹰嘴骨折病人36例,根据所使用内固定种类的不同分为Cable-pin系统治疗的Cable-pin组(19例)和克氏针张力带治疗的TBW组(17例),对每组病人术中情况、远期效果及并发症发生率等情况进行比较。结果所有病人均获随访,随访时间12~25个月,平均(13.00±4.68)个月。Cable-pin组在骨折愈合时间、术后优良率及并发症发生率分别为(12.2±2.3)周、78.9%和10.5%,TBW组分别为(16.0±2.2)周,58.8%和,35.3%,两组比较差异有统计学意义(P<0.05);Cable-pin组在手术出血量、术中耗时分别为(66.4±11.0)ml和1.5±0.6)小时,TBW组分别为(71.6±9.8)ml和(1.6±0.5)小时,两组比较比较,差异无统计学意义(P>0.05)。结论治疗尺骨鹰嘴骨折时,Cable-pin系统利于骨折愈合,固定可靠及并发率低。
基金supported by the National Meg-science Engineering Project of the Chinese Government
文摘The conductors of both the toroidal field (TF) and poloidal field (PF) coils of EAST are NiTi cable-in-conduit conductors (CICCs). The sizes of this type of CICC are 20.3 mm×20.3 mm and 18.5 mm×18.5 mm respectively. A relevant R&D program has been carried out for three years at the Research and Manufacture Center (RMC) of the Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP) to acquire the manufacturing techniques and master the behavior of the testing joints. Based on the experience gained from the manufacture and test of a sub-cable joint, three kinds of joints were made. The final design was determined after carefully evaluating their simple mechanism, good cooling line, lower AC loss and resistance, compact size, and convenience for manufacture and on-site assembly. Two steps were developed to carry out the final joint. The first step was forming the terminals' super conductors. The second step was clamping the two terminals together to ensure their good contact with the copper conductor sole. The two terminals could be connected in different directions to get two kinds of conductor connections. A hydraulic instrument was developed to impact the terminals. It could impact the terminals in high accuracy in terms of their size and shape. The cross section of the terminal was tried in circular and an elliptic shape. Five full-size joints were made according to the design and then tested. When they were tested in bathing cold condition, their resistance was from 2 nΩ to 4 nΩ The latest joint was tested in real working conditions where the resistance varied from 2 nΩ to 12 nΩ, depending on the testing current ranging from 2 kA to 10 kA.