High Frequency Mechanical Impact (HFMI) treatment offers a great opportunity to enhance the lightweight potential of welded structures using high strength steel materials. Focusing on the IIW Recommendations for the HFMI Treatment, a fatigue assessment based on the nominal, structural as well as notch stress approach is considered. Due to its sound applicability and proper assessment of the fatigue strength, the critical distance approach acts as a valuable concept in fatigue design, which has not been broadly studied in terms of HFMI-treated weld joints. Therefore, this paper deals with the application of the critical distance approach for welded mild and high-strength steel joints in both as-welded and HFMI-treated condition. Critical distance values were determined as a = 0.1 mm for as-welded specimens and a = 0.2 mm for HFMI treated specimens but for the sake of reliability, a = 0.15 mm have been proposed for HFMI treated welded joints.

高频机械冲击 (HPMI) 处理为提高使用高强度钢材料的焊接结构的轻量化潜力提供了绝佳机会。关注针对 HFMI 治疗的 IIW 建议，考虑了基于名义、结构和缺口应力方法的疲劳评估。由于其良好的适用性和对疲劳强度的正确评估，临界距离方法在疲劳设计中是一个有价值的概念，尚未在 HFMI 处理的焊接接头方面进行广泛研究。因此，本文讨论了临界距离方法在焊接态和 HFMI 处理条件下焊接软钢和高强度钢接头的应用。焊接试样的临界距离值被确定为 a = 0.1 mm 和 a = 0。