Abstract
In this study, results of X-ray radiographic examinations in situ of butt welds in 155 steel railway bridges in Poland are presented. In 34 bridges, cracks in 437 joints were found. Distribution and size of stresses in a section of weld weakened with those weld unconformities were determined as well as brittle fractures and fatigue cracks were discussed. Fatigue classes of elements without welds and butt welds, according to which concentration of stresses at selection of steel for brittle cracking and analysing of structures exposed to fatigue according to PN-EN 1993-1-10 and PN-EN 1993-1-9 should be made, were presented. In order to estimate the fatigue life of steel structures with imperfections, the author described his own fatigue investigation of steel of diversified ageing and four groups of butt welds. Fatigue strength curves obtained from particular tests were compared with standard curves.
Notes
1. Currently applicable bridge-related standards, PN-77/S-10050 and PN-82/S-10052, recommend conducting assessments of joint defectiveness based on radiograms according to PN-87/M-69772, not according to the current euro standards, PN-EN ISO 5817:2009 and PN-EN 12517:2001.