Fatigue Strength of Trolley Bridge Stringers Made of ASTM A7 Steel

Nineteen S15×42 (in U.S. units) stringers from a trolley bridge made of ASTM A7 carbon steel were tested in constant-amplitude fatigue. The bridge was built in 1900 and was abandoned in 1958. In 1985, the stringers were removed from the bridge and were tested in the laboratory. The test results showed that uniform corrosion and pitting reduced the fatigue strength of the stringers from Category A to Category D. The fatigue strength was reduced more by pitting than by uniform corrosion.