Low-Cycle Fatigue Testing of Shear Links and Calibration of a Damage Law

This paper experimentally studies the low-cycle fatigue (LCF) behavior of shear links in eccentrically braced frames (EBFs) with the aim of calibrating a convenient damage law for estimating the exhausted as well as remaining life of these members under any loading history. A total of 14 specimens are tested using a nearly full-scale EBF setup under constant-amplitude cycles as well as proportional and arbitrary loading histories. A generalized damage law is subsequently calibrated using results of the present study as well as a comprehensive data compilation of previous experiments for predicting the occurrence of link fracture under earthquake-induced loading histories. The approach forms a basis for the development of acceptance criteria based on cumulative measures which can be incorporated into the current performance-based design and evaluation procedures. For further validation, the procedure is applied to the case of EBF links fractured during the Christchurch earthquakes. Finally, the current standards for EBF shear links are discussed based on the findings of the LCF tests.