Research On Process And Mechanical Properties Of Magnetic Pulse Crimping Of GT185 Terminals And Aluminum Wires

The connection between cable harness and circuit components is generally completed through the crimping process.The reliability of the connection of the crimping joint is related to the safety performance of the whole circuit.According to the research,more than 60% of the power fa ults occur at the cable joints.Cable joint reliability pressure to ensure that during the service,the wire will have loose,because of the influence of the external force for cable joint,tiny loose can also lead to a significant boost,contact resistance when the contact resistance increases,the working temperature of joint will ascend,high temperature can accelerate the oxidation of the metal joint,this creates a tapping a vicious cycle of contact resistance increasing.In this paper,magnetic pulse crimping technology is applied to the crimping of cable joints,and a series of researches such as equipment development,numerical simulation,process test and mechanical property test are carried out on the large-diameter cable crimping joints.The specific research contents are as follows:First of all,in this paper,using the commercial software ls-dyna,established the coupled numerical model of electromagnetic field and structure field,boundary and finite element method is used to examine the cable jo int magnetic pulse pressure welding process,analyzes the terminals on the induced current,the distribution of electromagnetic field and electromagnetic force and magnetic pulse pressure welding process and the deformation process of terminals,wire and c able and through the numerical model of discharge energy,wire diameter and multipoint pressure welding on the joint forming process and the influence of the joint size morphology.On this basis,the numerical model of quasi-static crimping process is established,and the deformation process of cable harness and terminal during crimping process is analyzed.Secondly,the influences of technological parameters and structural parameters on the structural size and performance of the cable crimping joint were investigated by selecting different discharge energy,diameter of cable harness,position of the crimping contact and number of crimping times in the magnetic pulse crimping process experiment.It is found that with the increase of discharge energy,the increase of wire harness diameter and the smaller distance between the pressure contact position and the terminal end,the higher the degree of wire harness compaction,the better the tensile strength of the joint,and.In addition,with the increase of the number of times of compression,the peak load of the compression joints was significantly increased in the mechanical performance test,and with the increase of compression spacing,the peak load was higher.When the compression spacing was 28 mm,the impact of the increase of compression spacing on mechanical performance began to decrease significantly.Finally,the differences between the quasi-static and magnetic pulse compression joints are investigated by comparing their structural size,microstructure,mechanical properties and tensile failure modes.The cable bundles in different positions of magnetic pulse compression joints have uniform degree of compaction,and the surface of terminal compression area is smooth.The degree of cable bundle crimping at different positions of quasi-static crimping joints was different,and there were large voids between the wires,and obvious folds appeared on the surface of terminal crimping.By comparing the micro-morphologies of the terminals in the joint crimping area,it can be found that the outer wall edge area of the terminals has grain refining phenomenon,and the grain at the part of the terminal of the quasi-static crimping joint has the phenomenon of shifting to one position,and the degree of grain refining at different positions is also different.In addition,the quasi static pressure joint its peak tensile load are significantly lower than the magnetic pulse pressure joint,and the tensile failure state is different,the stretching process,the magnetic pulse compression joint its different wiring harness in the same strain level,and subjected to the stress size and more close,stretch,after the completion of magnetic pulse compression joint and quasi static pressure joint elongation phenomenon can occur in a wire and cable,but quasi static pressure joint wire elongation length gap is bigger.