The present study aims to investigate the extent to which the fatigue behaviour of laser beam‐welded AA6056‐T6 butt joints with an already existing crack can be improved through the application of laser shock peening. Ultrasonic testing was utilized for in situ (nondestructive) measurement of fatigue crack growth during the fatigue test. This procedure allowed the preparation of welded specimens with surface fatigue cracks with a depth of approximately 1.2 mm. The precracked specimens showed a 20% reduction in the fatigue limit compared with specimens without cracks in the as‐welded condition. Through the application of laser shock peening on the surfaces of the precracked specimens, it was possible to recover the fatigue life to the level of the specimens tested in the as‐welded condition. The results of this study show that laser shock peening is a very promising technique to recover the fatigue life of welded joints with surface cracks, which can be detected by nondestructive testing.

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关于激光冲击喷丸在缓和激光焊接AA6056表面疲劳裂纹方面的应用

本研究旨在探讨通过应用激光冲击喷丸可以改善已存在裂纹的激光焊接AA6056-T6对接接头的疲劳性能。在疲劳测试过程中，超声波测试被用于疲劳裂纹扩展的原位（非破坏性）测量。该程序允许制备具有约1.2mm深度的表面疲劳裂纹的焊接试样。与在焊接状态下无裂纹的试样相比，预​​裂纹的试样的疲劳极限降低了20％。通过在预裂试样的表面上进行激光冲击喷丸处理，可以将疲劳寿命恢复到在焊接条件下测试的试样的水平。