TWI Industrial Member Report Summary 251/1984
By J G Wylde, G S Booth and T lwasaki
This report describes the results of fatigue tests which have been carried out on welded tubular K and KT joints of 168mm chord diameter by 6mm wall thickness manufactured from steel to BS 4360 Grade 50C. The tests have been carried out under out-of-plane bending on joints with overlapping and non-overlapping braces. Evaluation of the strain concentration factors (SNCFs) for each group of specimens indicated that brace overlap and increase in brace wall thickness each produced increases in SNCF. The fatigue results in air compared well with existing data for specimens of other geometries. Free corrosion in sea water produced a relatively large reduction in endurance and limited results for cathodically protected specimens indicated that the in air behaviour was not restored.