The steel bellows damper is an elasto-plastic hysteretic damper installed between girder end and abutment to reduce damage of the superstructure and substructure. In the past fatigue tests, a low-strength material is applied to reduce stress concentration at the root positions of the bellows but it seems to be difficult to obtain their sufficient installation effects due to their yielding. Then, in this study, additional loading tests are carried out by focusing on the use of a high-strength material to the parts and a zinc aluminum alloy thermal spray to the bellows to enhance fatigue resistance and rust prevention. A mechanical model and fatigue strength evaluation method for bellows-type dampers were also studied.
