Development of a new steel plate possessing self-suppression effect for fatigue-crack propagation and properties of welded joints

With welded steel structures, fatigue-cracks usually occur at the welded joints. Therefore the structures are designed to reduce stress at the points where fatigue damage is expected. It is, however, impossible to totally prevent fatigue-cracks from occurring. Moreover, in a complex structure, there is a possibility that a simple method such as visual inspection does not enable the detection of the occurrence of a fatigue-crack at the welded joint at an early stage, and hence it can have grown into a long crack by the time it is discovered.