抄録
Considering steel buildings under seismic loads, fatigue tests of notched round bars of a high strength steel are carried out to investigate characteristics of ultra-low-cycle-fatigue crack growth that may occur under large scale yielding in which plastic deformations are dominant. The relationship between the crack growth characteristics, the cyclic R curve and the static R curve is discussed. The final fracture occurs by plastic collapse. A method of crack growth analysis and life prediction is proposed to evaluate the structural integrity of buildings in addition to the normal plastic limit design.
