Full-size testing to determine stress concentration factors of dragline tubular joints

This paper describes the determination of stress concentration factors (SCFs) of dragline tubular joints through laboratory testing of four full-size dragline tubular joints. Strip gauges are installed both outside and inside the footprint of the joints to measure stress distribution at the weld toe and weld root. Measurements for SCF are carried out for two load cases, i.e. tension or compression forces in the main chord alone and tension or compression forces in the vertical bracings alone with reaction forces in the inclined braces. The relationship of the SCF between the corresponding weld toes and weld roots are presented in the paper. The weld profile and weld root gaps that have been measured using the silicon imprint technique and feeler gauges, provide valuable information for future FE simulation and weld root failure study using the effective notch stress approach.