Fatigue life calculation method of welded steel bridge structure

Abstract

The invention discloses a fatigue life calculation method of a welded steel bridge structure. The method comprises steps as follows: a steel fatigue resistance total-space S-N curve model with average stress modification taken into consideration is established; the real stress time history of steel bridge welding details is calculated in consideration of the coupling effect between welding residual stress and vehicle load stress; the real stress time history is processed with a rain flow counting method, and the stress amplitude, average stress and stress cycle number under the condition of single open traffic are calculated on the basis of a processing result; by use of the established total-space S-N curve model with average stress modification taken into consideration, the total stress cycle number corresponding to the stress amplitude and the average stress is calculated; on the basis of the calculated stress cycle number under the condition of single open traffic and the total stress cycle number, the fatigue life of steel bridge welding details is calculated. The influence of the average stress effect on the fatigue life of the welded steel bridge is accurately considered, the defect that existing steel bridge fatigue design standards for fatigue life are too high is overcome, and the method is worth wide application and popularization.

Description

technical field [0001] The invention relates to a calculation method, in particular to a fatigue life calculation method of a welded steel bridge structure. Background technique [0002] Most modern long-span bridges use steel bridges. For example, since China’s Humen Bridge first used steel box girder bridges in 1997, long-span steel box girder bridges have been widely used in China’s river-crossing and sea-crossing bridges. These bridges are China's transportation hubs and bear huge traffic pressure. However, the problem of fatigue cracking of steel bridges has plagued these bridges since their operation. In the two economically developed regions of China, the Pearl River Delta and the Yangtze River Delta, there are two typical bridges. The Humen Bridge opened to traffic in 1997, and fatigue cracks occurred five years later; the Jiangyin Bridge opened to traffic in 1999, and fatigue cracks were also discovered nine years later. The premature fatigue cracking of steel br...

AI Technical Summary

Problems solved by technology

The problem of premature fatigue cracking of steel bridges leads to huge economic losses and safety hazards

However, the fatigue life of the welding details of these steel bridges calculated by using European, American or Chinese steel bridge fatigue design codes at home and abroad is much longer than the bridge design life of 100 years, which shows that the existing steel bridge fatigue design codes overestimate the welding Fatigue life of details

Images