Evaluation of Fatigue Strength of Load-Carrying Cruciform Welded Joint under Combination of Axial Loading and Out-of-Plane Bending

The influence of out-of-plane bending stress on the fatigue performance of load carrying cruciform welded joint where fatigue crack originates from weld root was experimentally and analytically examined. For the experimental work, fatigue tests with three types of specimens were conducted under combination of axial membrane loading and out-of-plane bending loading. Since the influence of out-of-plane bending stress applied in this fatigue tests are small about 20 similar to 25% of inerribrane stress, the influence of out-of-plane bending stress is not observed, that means the fatigue performance under combination loading with such small out-of-plane bending stress can be assessed with only membrane stress range. For larger out-of-plane bending stress, the influence of out-of-plane bending stress was analytically examined by effective notch stress concept.