Analysis Of Mechanical Properties Of Aluminum Conductor Composite Core Structure In Tension And Bending

In recent years,along with the rapid industrial development,national life level rising steadily,the demand for electricity is also growing rapidly,so how to improve the transmission capacity of transmission lines is an urgent problem in the field of power transmission in China.Capacity increase wires can be used without replacing the original pylon supporting facilities,by simply replacing the original old wires to improve the transmission capacity of overhead wires.Because of its significant economic cost advantage,it has a broad development prospect in the upgrading of overhead wire lines of power grid.Aluminum conductor composite core as a new type of capacity increase wires,it has the advantages of high structural strength,light weight,small sag and convenient construction on the premise of increasing the wires carrying current,it is the key component of the new overhead transmission line in the power industry.Structurally,it generally has the characteristics of special-shaped section,non-bonding and spiral winding.At present,the mechanical property analysis of this wire is not enough in China,especially its overall mechanical performance analysis,there is no perfect theoretical model and the experiment tested the finite element model,which limits the engineering application of aluminum conductor composite core in some extent.Therefore,launching the mechanical properties of aluminum conductor composite core,and analyzes the influence of key parameters on the mechanical properties of the whole structure which has important basic theory and engineering application research value.For the above challenges of mechanical property analysis,this paper takes aluminum conductor composite core as the research object,carry out analysis and research on the mechanical properties of its structure under tension,bending and combined loads.The specific contents include the analysis of its axial elongation and tensile stiffness under tensile load,the bending stiffness of the wire structure under bending load,the bending deformation,stress distribution and energy dissipation of wire under the combined tension-bending load,and the thermal-mechanical coupling condition(temperature rise and axial tension)on the mechanical behaviors,etc.Firstly,the theoretical models of axial displacement,tensile stiffness and bending stiffness of aluminum conductor composite core with special-shaped section were derived.Then,a parameterized finite element simulation model was established to analyze the mechanical behaviors under the tension,bending,tension-bending,and thermal – mechanical coupling conditions,verified the rationality of this theoretical model established.Finally,a complete set of laboratory prototype testing equipment for tensile and bending mechanical properties of aluminum conductor composite core was built.Developed test fastening joints and joint steel pipe clamping devices,it effectively solves the problem that the central component of the wire and the temporary experimental joint cannot synchronously deform,completed the aluminum conductor composite core tension and bending mechanics performance test,and compare with the numerical results to verify its prediction accuracy.Through comparative analysis,we found that the theoretical model and finite element numerical analysis model established in this paper have high prediction accuracy for the mechanical behavior of the aluminum conductor composite core under tension,bending and their combined work.It provides a reliable theoretical basis and numerical tools for its engineering application in the power grid system reconstruction in China.To provide the corresponding theoretical basis for its popularization and use in China’s power grid system transformation line,which is conducive to accelerating the livelihood task of upgrading infrastructure construction in China.