Abstract
The results of fatigue tests on high strength bolted tee connections are described herein. The type of test specimens is the most simple type of tee connections and two cut-tees are bolted together by two high strength bolts. Influential parameters on the fatigue strength are the thickness of the tee-section flange, the ratio b_0/a (a : the distance from the bolt line to the edge of flange, b_0 : the distance from the bolt line to the web line) and the initial clamping force of the high strength bolts. The specimens are six types and total numbers of specimens are sixty seven. The results are followings. The fatigue strength of tee connections is influenced by the prying force and the bending force resulting from deformation of tee-section flangesas same as the static strength. The static strength is not influenced by the initial clamping force but the fatigue strength is influenced of that very much. The decrease in the initial clamping force results in the decrease in the fatigue strength. Considering that the fatigue failure were caused in the high strength bolts in tee-connections, the fatigue strength is estimated by the bolt tension versus applied load relationship which have a stable condition after one loading cycle. And this relationship will be estimated from the static analysis. Consequently, if the fatigue failure is caused in the high strength bolt, the fatigue strength of tee-connections will be roughly estimated, and if the bending force in the high strength bolt is concidered, the fatigue strength will be estimated more accuratelly.
