Aerial cable bending rigidity experiment method and device under stretching and bending combination

Abstract

The invention belongs to the field of aerial cable testing, and relates to an aerial cable bending rigidity experiment method and device under stretching and bending combination; a traditional three-point bending test cannot measure the response of an aerial cable under the action of a stretching and bending combination load, and the scheme provides the aerial cable bending rigidity experiment device and an experiment method. According to actual working conditions, a load equivalence method is adopted. The three-point bending test is improved; a set of experiment support composed of a base support, an extension frame and a vertical supporting frame is designed; radial tension is applied by using a universal testing machine; weights are suspended at two ends of a sample cable to apply axialtension to the sample cable; the tension output from the universal testing machine and displacement data of the middle point of the cable body are combined with data of the two laser sensors symmetrical to the middle point, and a hysteretic curve of bending moment and curvature of the aerial cable under repeated reciprocating stretching and bending combination is calculated and analyzed, so thatthe change of bending rigidity is studied.

Description

technical field [0001] The invention belongs to the field of overhead cable testing, and relates to an experimental method and device for bending stiffness of an overhead cable under combined pulling and bending. Background technique [0002] As an important equipment for power transmission, overhead cables play a role in power transmission. As the distance between the two towers becomes farther and farther away, the overhead cables are suspended in the air, and are more and more affected by the alternating tension and bending loads under the action of wind. The fatigue life is very important. [0003] Due to the special structure of overhead cables, the internal functional unit is formed by twisting multiple layers of wires at a certain helical angle. When the wire layer is subjected to a large bending moment, the wires between layers will slide, and under the action of tension, The inner wires will tighten again, so the bending stiffness of the overhead cable will change...

AI Technical Summary

Problems solved by technology

However, the existing three-point bending test equipment can only measure the stiffness change of a single bending, but cannot perform multiple bendings, and cannot apply tension to the sample cable

The relevant experimental equipment is developed for large-diameter flexible pipe cable bending equipment. When it is used in the bending test of overhead cables, the problem of insufficient accuracy will occur.

Images