Issue 29

L. Contrafatto et alii, Frattura ed Integrità Strutturale, 29 (2014) 196-208; DOI: 10.3221/IGF-ESIS.29.17 206 Figure 17 shows the evolution of the failure mechanism in term of maximum principal stress for test A-10-5, while in Fig. 18(a) the crisis mechanism of sample B-10-3-2 at the pull-out strength is compared with the experimental one. Fig. 18(b) represent the corresponding plastic flag. The percentage error in the pull-out strength estimation was always in the order of 5%. Figure 16 : Test B-14-10. Steel rod failure. Figure 17 : Test A-10-5 . Evolution of the radial stress (a) (b) Figure 18 : Test B-10-3 . Radial principal strain (a) and plastic flag at the peak load (b) . C ONCLUSIONS he numerical prediction of the failure mechanism of anchor systems chemically bonded in natural stone requires sophisticated computational tools for capturing all the evolution of the crisis process, as for instance those used in the present paper or many other, equally rich, often implemented in advanced commercial F.E. codes. The entire phenomenon is actually complex due to the presence of three different material characterised by quite different mechanical properties. Professional software, generally used by technicians in the field of construction and by the