Dipl.-Ing. Peter Gerster

 

Abstract
The paper presents the application of UIT (Ultrasonic Impact Treatment) in the construction of the high span bridge, over the A37 highway, at Lichtenfels, in the Oberfranken county from Germany. The UIT (Ultrasonic Impact Treatment) technology was presented in the June issue of the review „Der Praktiker”, in 2008 (this paper was published also, in the SUDURA review, no. 3/2009).
The tie-bar joints of the welded pipes, in the bridges construction in Germany, represents a novelty, because they are made without the cast additional parts, which are very expensive.
These tie-bar joints were been subjected to tests concerning the lifting capacity and the service reliability, also the resistance in service. The obtained results of these tests are presented in this paper.
The fatigue tests results showed that at the same loading, the sample lifetime is increased approximately by 5 times, if the sample was subjected to UIT. Taking into consideration the good results obtained, it was decided that all the 32 tie-bar joints of the welded pipes, corresponding to 16 elongation diagonals of the bridge, subjected to highest loading, to be treated by UIT.
Finally, there are presented the future trends of the UIT application.