Behaviour of Steel Beam-to-Column Joints Under Cyclic Reversal Loading: An Experimental Study

An experimental study was carried out to investigate the low-cycle fatigue behaviour of beam-to-column joints. Several full-scale specimens were tested, in a multi-specimen testing program, using constant amplitude displacement histories, to develop a cumulative damage model. This model is based on S-N line approach and, although proposed here for low-cycle fatigue, was derived and is valid also for high cycle fatigue. Possible definitions of parameter S , as well as, failure criteria for the definition of N , are compared. The influence of the definition of parameter S on the value of the slope of the S-N line is discussed. A statistical method for the assessment of the S-N lines, based on a given probability of failure with reference to suitable levels of safety and reliability of the structural joints, is also presented.