Issue 28

A. Brotzu et alii, Frattura ed Integrità Strutturale, 28 (2014) 19-31 ; DOI: 10.3221/IGF-ESIS.28.03 27 Figure 15 : Load vs displacements plot of the extraction test carriedout with gel lubricant. Figure 16 : Load vs displacements plot of the extraction test carriedout without gel lubricant. Figure 17 : Unwinding failuremechanismon instrument no. 9. Figure 18 :Micro cracks on instrument no. 9 surface. Figure 19 : Deep cracks of instrument no. 9. Figure 20 : micro crack of instrument no. 7.