Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
777334 | International Journal of Fatigue | 2007 | 9 Pages |
Fatigue properties of tailored welded blanks with the same material and different thickness were investigated. Fatigue tests of specimens with angles of 0°, 70° and 90° to the laser weld line were performed in order to clarify the influence of loading direction and thickness ratio. The levels of stress range affected the crack initiation areas of the 0° and 90° specimens, and simple heterogeneous mechanical models roughly expressed the macroscopic fracture behavior. The fatigue strength of the 0° specimens was almost the same as that of the base metal. In the 90° specimens, fatigue strength showed a clear decrease under relatively low stress range. Insufficient grinding of the 70° specimen edge caused crack initiation at the weld toe and low fatigue strength. An increase of thickness ratio induced a decrease of fatigue strength of the 90° specimen, although that of the 0° specimens was independent of thickness ratio. Fatigue crack propagation analyses under cyclic stress distribution revealed a close correlation with the test results. These experimental and analytical results were less sensitive to thickness ratio than estimations by elastic stress concentration factors.