| The Large Cross-section Conductor consists of a number of hard aluminum wires and galvanized steel wires.The core is made of multiple galvanized steel wires.The outer concentric spiral is wound with four layers of hard aluminum wires.The nominal cross section of the aluminum conductor is not less than 800mm~2,As a new type of high-performance wire,it not only plays an important role in the UHV transmission line project that has been built in China,but also has broad application prospects in the future development of the power grid.However,as the cross-sectional area of the wire increases,the construction process and difficulty also increase.the matching joint pipe has a large change in the force and deformation of the connecting pipe and the traditional cross-section wire.In recent years,although engineers and technicians have mastered the best method for crimping large-section wires in construction technology,there are few studies on theoretical analysis,especially on the load-slip curve of the connecting pipe-conductor system.Therefore,the finite element analysis and experimental study on the mechanical properties of large-section wire joints after joint connection are carried out.The main research work and achievements are as follows:(1)In order to explore the influencing factors of the stress distribution of the connecting pipe-aluminum stranded wire(steel strand)system,the ABAQUS finite element analysis software is used to simulate the crimping of the connecting pipe-conductor system under real working conditions,and the data is sorted to obtain the connection.The elasto-plasticity and Mises stress distribution of the tube-conductor system are analyzed and analyzed.The inner diameter,outer diameter and length of the nozzle are constant,and the angle of the tip is taken as the variable to explore the different size of the tip.The influence of stress distribution on the pipe joints(steel strands)of the connecting pipe;the coincidence length of the crimping steel die is used as a variable to explore the stress on the overlap length of the different crimping steel die and the pipe joint(steel wire)The impact of distribution.(2)In order to explore the load-slip curve of the connecting pipe-conductor system under different margins,the NET standard is used as the crimping condition,and the ABAQUS finite element analysis software is used to simulate the steel strand-steel connection.The load-displacement curve of the tube,aluminum wire-aluminum joint pipe under the condition of0.86D,0.86D+0.1,0.86D+0.2.In order to investigate the load-displacement curves of the connecting pipe-conductor system under the condition that the connecting pipe-conductor system has different lengths of the margins and the loss of the crimping length,the steel strand-steel connecting pipe and the aluminum wire-aluminum joint are respectively studied.The load-displacement curve is obtained when the tube has a margin of 0.86D,0.86D+0.1,0.86D+0.2 and respectively loses the crimp length of 1%-6%.(3)The axial tensile mechanical properties of the three sets of connecting pipe-conductor system were tested,and the correctness of the finite element model was verified.By modifying the size of the large-section wire connecting pipe and performing a large number of numerical simulation calculations,the pair was completed.Reasonable optimization of the length of the tapping of the large-section wire connecting pipe,the effective crimping length,and the inner diameter. |
