Issue 41

F. Berto, Frattura ed Integrità Strutturale, 41 (2017) 464-474; DOI: 10.3221/IGF-ESIS.41.58 471 The stress concentration factor K t (  f ) of the fictitiously rounded notch is defined as follows:   max ( *, ) K t f n s      (21) The relative deviation can be defined as follows:     t f t t f Δ K K K     (22) Figure 3 : Geometry and dimensions of the double-V-notched quadratic plate specimen considered in the FE analyses; remote loading by prescribed nominal stress  n ; dimensions w = 100 mm and 2 a = 14.14 mm; real pointed versus fictitiously rounded (root hole) V- notch 2  (°)  (°) K 1 (MPa mm 1-  1 ) K 2 (MPa mm 1-  2 )  1  2  0 (°)  M s 45 15 472 128 0.550 0.660 –13.49 0.272 0.169 2.56 30 376 222 0.550 0.660 –25.73 0.592 0.340 3.16 45 244 257 0.550 0.660 –36.52 1.053 0.516 4.24 60 112 223 0.550 0.660 –46.70 1.993 0.704 6.08 Table 1 : Notch stress intensity factors K 1 and K 2 and crack propagation angle   0 for different mode ratios M resulting in support factors s. C OMPARISON WITH FE RESULTS he maximum stress  max (  *, s ) has been determined in this section directly by means of finite element analyses modeling the plate shown in Fig. 3 with  f = s  * , while  values are those evaluated analytically. The finite element analyses (FEA) were carried out by using Ansys (release 13.0). In total 2000 models have been analysed, each model T  f 2 a w w    n 