Experimental Investigation on the Crack Closure Phenomenon Using Barkhausen Noise Method

This paper presents an experimental investigation on a middle tension (MT) specimen made of a low carbon structural steel subjected to cyclic loading. The work was aimed to assess the effectiveness of Barkhausen Noise method in detecting the crack closure phenomenon. The Influence of probe orientation and position ahead the crack tip was examined, in order to optimize the magnetic measurements. A filtering procedure was also used to treat the Barkhausen Noise signal. A procedure was proposed to determine the crack-opening load from it. On the same specimen, some strain gauge measurements were carried out to determine the crack-opening load by the local compliance method. The results showed a good agreement of the results obtained with the two experimental techniques.