A new hybrid testing procedure for the low cycle fatigue behavior of structural elements and connections

The current test recommendations adopted for the assessment of low cycle fatigue of steel building elements and detail are briefly described, and some disadvantage and incompleteness of these procedures are discussed, particularly in what regards the ultimate bearing capacity and the difficulty to represent the cumulative displacement behavior of elements and details in one direction. In order to overcome these problems, a new testing procedure is proposed, whose aim is to take explicitly into account the actual exercise load and its influence on the cyclic behaviour, particularly for the cumulative displacements, and on the effective collapse condition. The proposed cyclic test is a hybrid procedure where the sequence of reversed cycles have an initial force-controlled part, up to the applied vertical load, and a final displacement-controlled part.