ANALYSES OF FATIGUE TEST DATA OF OFFSHORE TUBULAR JOINTS

A paper-surveying on fatigue tests of tubular and foundamental joints for offshore structure design was carried out and tested data were collected. The collected data were arranged as two sets of data base : the data base on tubular joint tests and the data base on foundamental joint tests including cruciform joints, butt-welded plates and so on. Based on these data bases, the regression analyses were conducted in order to evaluate effects of factors on the fatigue strength of these joints. Plate thickness, material, load ratio, random loading, corrosive environments, grinding, TIG-dressing etc. are included in these factors.Correlations between the effect of each of these factors on the fatigue strength of foundamental and tubular joints were discussed and it was, generally speaking, found that the correlations are good. Finally, the current fatigue design curves were compared with the collected data and the extent of safety of the curves were confirmed.