ABSTRACT
Usually, an inspection for fatigue cracks in steel structures is often executed with visual inspection, penetrant testing and magnetic particle testing as necessary. However, the visual inspection depends on inspectors’ knowledge and skills, so overlook of cracks can occur. Non-destructivex inspection such as penetrant testing and magnetic particle inspection cannot detect fatigue cracks inside steel plates. Therefore, the authors proposed cracks detection method focusing on the ratio of stress amplitudes between two directions near the weld as an auxiliary mean of an inspection of steel structures. In this study, we verified whether cracks can be detected quantitatively by comparing and examining the results of vibration fatigue test and FEM analysis for the welding lines of trough rib in orthotropic decks. As a result, fluctuations in the ratio of stress amplitudes are confirmed due to the occurrence and progress of cracks. This method isn’t dependent on inspectors’ knowledge and skills, may be able to detect damage inside the structure, so it can be an auxiliary mean of the existing inspection method.
