Earthquake-induced damage updating for remaining-life assessment of steel frame substructure systems

This paper presents a framework combining theoretical, numerical, and experimental approaches for evaluating the remaining-life of high-rise steel buildings based on earthquake-induced fatigue damage propagation in local beam-to-column connections. A mesh-independent finite element model is developed and implemented using the concept of lumped damage mechanics to estimate the fatigue-induced life loss associated with the extent of crack propagation until complete rupture failure occurred in beam-to-column connection substructure of high-rises. In this framework, a damage state variable is intro-duced at each end of beam elements and can be linked to the extension of the fatigue frac-ture in real frame building joints. Then, the damage evolution law is developed by extending the conventional Manson?Coffin law and a new crack-driving parameter to quantify the extent of damage states and predict the remaining life of the associated com-ponents in high-rises buildings. The proposed model is validated by a damage index mea-sured from the local wireless sensors in substructure tests of ductile steel beam-to-column connections subjected to ultra-low cycle fatigue loadings. The residual resistance can be quantified by updating the damage curve with the identified damaged conditions. ? 2021 Elsevier Ltd. All rights reserved.