Abstract: As the main load-bearing parts of composite core conductor, the composite cores have been under long-term galloping and torsion effects during their service life. Considering the low toughness of composite materials, the safety and reliability of these cores under the influences of galloping and torsion become a key problem concerned by power grid operators. In this study, the mechanical properties of composite cores were evaluated after different numbers of galloping, which provided an objective assessment of the safety and applicability of the composite cores. From the results, the carbon fiber wires show complete broken strands after 900,000 times of galloping under 25% RTS tensile load. In comparison, carbon fiber composite cores was able to retain a tensile strength of over 90% RTS after a continuous galloping for 1,000,000 times, without any damage. Their mechanical strength was still higher than 90% RTS after 1,000,000 times of galloping under the tensile load of 25% RTS. All results indicated that the carbon fiber composite core can meet the safety requirement for long-term uses in high voltage wires.

Key words: carbon fiber composite core, galloping property, torsion property, damage performance