MEASUREMENT OF CORROSION ROUGHNESS OF GALVANIZED BRIDGE WIRES AND FATIGUE STRENGTH OF WIRES WITH ARTIFICIAL PITS

Measurements of corrosion pits of galvanized bridge wires were conducted. It is found that severer corrosion produces deeper pits in more condenced areas. Fatigue tests with three different artificial pit shapes were then performed. Wires with a round pit shape have higher fatigue strength, and the fatigue strength of the wires with a triangle pit shape is lower than that with a round shape. The wires with nothched triangles have the lowest fatigue strength because of high stress concentration. The fatigue tests results with artificial pits corresponded to those of actual corroded wires, which shows that the main factor of reduction of fatigue strength is the surface roughness caused by corrosion.