Experimental analysis of lightning stroke on bridge cable

Because of the huge structure and special position, bridge is vulnerable to lightning stroke. As the most important bearing member of cable supported bridge, once the cable suffering the lightning stroke, the structural safety of the bridge will be affected. The bridge cable used actually was sampled and carried out lightning stroke simulation experiment in laboratory, the influence of lightning stoke on bridge cable was analyzed through five experimental models, the truth that lightning stroke can cause high-tensile steel wire melting loss was discovered. The tensile strength change of high-tensile steel wires before and after the lightning stroke was analyzed through tensile test, the result shows that tensile strength of high-tensile steel wires is reduced significantly. The breakdown strength of high density polyethylene sheath was calculated through impulse voltage breakdown test, the result shows that the high density polyethylene sheath can not endure the lightning stroke in nature. Experimental analysis indicates that the lightning protection of the bridge cable must be strengthened.