Fatigue assessment of a steel frame subjected to a number of earthquake excitations

摘要

It is well known that fatigue is a reason for structural failure in steel structures. Connections in steel bridges and in steel building frames can be ruptured due to fatigue. This paper focuses on the fatigue assessment of steel frame subjected to earthquake loads. Adapting, the theory of high and low cycle fatigue, a procedure for estimating a fatigue damage limit state for earthquake design is proposed. The method can be applied for damage assessment of the existing structure to past earthquakes excitations. Results of linear and nonlinear analysis are combined with fatigue-damage design curves to predict failure or the remaining useful life after a scenario of earthquakes. A three story moment resisting steel frame is examined. The frame is solved under seismic actions with linear and non-linear time history analysis. Fatigue methods are applied to various loading scenarios, fatigue life and damage index are estimated.