2019 Volume 75 Issue 3 Pages 184-195
This study presents fatigue life prediction of steel-concrete joint system based on the experiments of wind turbine model subjected to uniaxial or bi-axial vibration. The wind turbine model was tied to the biaxial shake table, then was vibrated at most 200,000 cycle to induce fatigue damage of concrete in joint system. The model subjected to bi-axial vibration showed rapid increase of horizontal displacement at tower when the number of vibration was about 2/3 or half of the one subjected to uniaxial vibration. Several particular cracks were observed at the cross section of pedestal and footing after the test. The ultimate capacity of the model was estimated by fatigue strength of concrete estimated by JSCE standard. The number of vibration during the variation of input amplitude was converted to the equivalent number by Miner’s low. The S-N diagram for uniaxial vibration obtained in this study showed good agreement of S-N diagram for ordinary concrete.