Fatigue improvement of welded steel joints by high frequency mechanical impact treatment

The International Institute of Welding (IIW) technical working units provide unique forums for knowledge exchange to experts and professionals from industry, research institutes and world-leading universities. Developing science-based and industrially-relevant best practice guidelines is a key objective of these units. In the past decade, high frequency mechanical impact (HFMI) has significantly developed as a reliable, effective and user-friendly method for post-weld fatigue strength improvement technique for welded steel structures. The development of a new guideline for the design of structures improved using high frequency mechanical impact is presented. The extra fatigue strength benefit for high frequency mechanical impact treated high strength steels is also presented. Important issues like high frequency mechanical impact equipment, proper treatment procedures, operator safety, training, quality control measures and documentation are briefly discussed. Aspects of this guideline and the unique international nature of the IIW which has made it possible are described.