Method and system for evaluating fatigue life of high-voltage composite cross arm

Abstract

The invention discloses a method and a system for evaluating the fatigue life of a high-voltage composite cross arm, and the method comprises the steps: calculating the dynamic mounting force of the cross arm generated by the conductor galloping of a high-voltage transmission line according to the conductor galloping theory; establishing a finite element model of the high-voltage composite cross arm, determining a key section with the maximum stress, applying a dynamic load to extract a stress time history of the key section in the cross arm structure, and taking the stress time history as a basis for fatigue evaluation; fitting a stress amplitude-fatigue life S-N curve by utilizing fatigue test data of the composite cross arm, estimating the service condition of the composite cross arm byutilizing historical data of conductor galloping, and estimating the expected fatigue life of the composite cross arm. According to the method, a more complete method for evaluating the service lifeof the high-voltage composite cross arm structure is formed, so that the service life evaluation of the high-voltage line cross arm is more accurate.

Description

technical field [0001] The invention relates to a method and system for evaluating the fatigue life of a high-voltage composite cross-arm, belonging to the field of electric power transmission. Background technique [0002] Compared with traditional cross arms, resin and glass fiber composite materials have the advantages of light weight, high strength, and good insulation performance, and their applications in transmission lines are developing rapidly. At present, composite cross-arms are mainly used in transmission lines with lower voltage levels of 220kV and below. The operating load of low-voltage lines is relatively simple, and the material strength method of static load is generally used for design and safety check. [0003] Composite cross-arms are rarely used in ultra-high voltage transmission lines of 500kV and above, and the cross-arm structure is also different from low-voltage lines. Compared with low-voltage lines, the safety, durability and long-term reliabili...

AI Technical Summary

Problems solved by technology

Further research shows that the alternating load caused by the galloping of the transmission conductor is far greater than other loads, and it is one of the most important factors affecting the fatigue of the cross-arm, but the existing evaluation methods do not take into account the impact of the galloping of the conductor on the cross-arm

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