The Peak Stress Method applied to fatigue assessments of steel tubular welded joints subject to mode-I loading

The paper presents the practical aspects involved in structural design of tubular joints mainly employed in roller coasters manufacturing. Different design standards, commonly adopted in fatigue assessments, are considered and compared. Then some constant amplitude fatigue test results concerning typical tubular welded joints are presented. Finally the experimental results and additional test data taken from the literature are compared with the theoretical estimations based on the Peak Stress Method, which has been recently conceived and proposed as a simplified, application-oriented version of the well known Notch-Stress Intensity Factor approach. The results indicate that the Peak Stress Method is suitable to estimate the fatigue life up to crack initiation of tubular welded joints subject to mode-I loading.