With the continuous upgrade of the power system, various new products have emerged, such as steel core aluminum stranded wire, aluminum clad steel core aluminum stranded wire, aluminum clad steel core aluminum alloy stranded wire, aluminum alloy stranded wire, aluminum alloy core aluminum stranded wire Wire, aluminum-clad steel core heat-resistant aluminum alloy stranded wire, etc. However, the overall tensile performance has always been a major issue that plagues the design of overhead stranded wire products.
The rated breaking force of the wire is calculated based on the strength of all aluminum single wires and reinforcements. However, the actual breaking force will deviate from the actual calculated value. The main reason is that the strength of each single wire is not fully utilized. Therefore, when designing a product, not only must it meet its strength requirements, but also how to dig out the strength of each single wire. Not only is the material fully utilized, the overall performance of the wire will also be greatly improved. You can start from the following aspects.
1. Starting from strength, adjust the uniformity of each single wire.
According to the strength of each single wire, the degree of bearing stress is also different. Just as the tension sensor has a stretching range, exceeding its range will not only damage the equipment, but also cause data deviation. The same is true for aluminum single wires, and aluminum single wires of different strengths have different stress bearing degrees. When these single wires with large strength deviations are twisted together, the stress is evenly distributed to each single wire. The single wire with low strength will break early due to insufficient load, and the single wire with high strength will not play its role. . Therefore, extremely poor strength is an important parameter for testing the utilization of mechanical properties.
2. Adjust the size of elongation and pitch diameter ratio based on elongation and pitch diameter ratio.
The elongation of the steel wire also has a great influence on the overall tensile properties. A large number of experiments have proved that the overall breaking force of aluminum-clad steel-cored aluminum stranded wire is prone to failure. The main reason is that the elongation of aluminum-clad steel is too small. The utilization rate of the mechanical properties of the aluminum wire is too low. When the aluminum wire is twisted, the smaller the pitch, the better the ductility. The higher the elongation requirements of the steel wire. The elongation of aluminum-clad steel wire is about 1.0, and the elongation of aluminum wire is also about 1.0. In addition, the elongation of the steel wire is far from enough. Therefore, the conductor design for aluminum-clad steel wire can appropriately increase its pitch diameter ratio, reduce the gap between the elongation of the aluminum-clad steel wire and the aluminum wire, and give more play to the mechanical properties of the aluminum wire. In short, aluminum wire elongation + pitch elongation = steel wire elongation.
3. Starting from the arrangement structure, the single wire with larger elongation is arranged on the outer layer.
Tests have proved that most single-line fractures are in the outer layer. The elongation of the outer layer is also a key factor affecting the overall breaking force. When the strength of the single wire is constant, the higher the elongation rate, the mechanical properties of the high strength single wire can be exerted to a large extent.
At present, the performance of most of the wires has not been fully utilized, and the margin is large. This process is a long-term process of exploration and requires a lot of experiments and data analysis. This is just a concept, and the focus is on practice. In short, when designing a product, the goal is that when the wire is stretched to 1%, all single wires can play an effect, so that the overall performance of the wire will be greatly improved.
