Main Factors Affecting The Overall Tensile Performance Of Overhead Conductors

- Mar 21, 2018-

With the continuous upgrading of the power system, a variety of new products came into being, such as steel core aluminum stranded wire, aluminum steel core aluminum stranded wire, aluminum steel core aluminum alloy stranded wire, aluminum alloy stranded wire, aluminum alloy core aluminum stranded wire, aluminum clad steel core heat-resistant aluminum alloy stranded wire.

However, the overall tensile properties have been a major problem in the design of the overhead stranded wire products. The rated tensile force of the conductor is calculated from the strength of all the aluminum single and reinforced parts. But the actual tensile force will be a certain deviation from the actual calculated value, the main reason is that the strength of each single line is not fully utilized. So in the design of products not only to meet its minimum strength requirements, but also to consider how each single line of strength are dug out. Not only the material is a full use, the overall performance of the wire will also be greatly improved.

Can start from the following aspects.

First, from the intensity, adjust the uniformity of each single line. Each single line according to the size of its strength, the load on the stress is also different. Just as the tensile sensor has the best stretching range, exceeding its range will not only damage the device, but also cause data deviation. Aluminum single line is the same, the different strength of the aluminum single line on the load of stress is also different. When these strong deviation of the larger single stranded together, the stress is evenly distributed to each single line, the strength of a small single line will not be due to the bearing level of premature rupture, and the strength of a single line can not play its role.

Therefore, the intensity of extreme difference is the test of mechanical properties of the use of important parameters.

Second, from the elongation and the ratio of the pitch to adjust the elongation and the size of the pitch ratio. The elongation of steel wire has a great effect on the overall tensile properties. A large number of experiments have proved that the overall tensile force of aluminum-clad aluminum-cored wire is prone to failure. The main reason is that the elongation of aluminum-clad steel is too small. The utilization of mechanical properties of aluminum wire is too low. When the aluminum wire is twisted, the smaller the pitch, the better the ductility. The higher the elongation of the steel wire is required. and aluminum-clad steel line elongation at about 1.0, aluminum wire is about 1.0, plus the expansion of the hinge-pitch, steel line elongation is far from enough. Therefore, the wire design of al-clad steel wire can increase its pitch-diameter ratio, reduce the gap between aluminum-clad steel wire and aluminum wire elongation, and give more play to the mechanical properties of aluminum wire.

In short, the elongation of aluminum line + due to pitch elongation = steel line elongation.

Third, from the arrangement of the structure of a single line of higher elongation at the outermost. The test shows that the single break is mostly in the outermost layer. The outermost elongation is also a key factor affecting the overall tensile force.

When the single line strength is certain, the higher the elongation, can make the single line mechanical performance of high intensity to play the maximum function. At present, most of the performance of the wire is not fully played out, the margin is very large, this process is a long-term groping process, the need for a large number of experiments and data analysis, here is just a concept, emphasis on practice. In short, in the design of products, the ultimate goal is when the wire elongation to 1%, all the single line can play to the best effect, so that the overall performance of the wire will be greatly improved.