Issue 48

M. K. Hussain et alii, Frattura ed Integrità Strutturale, 48 (2019) 599-610; DOI: 10.3221/IGF-ESIS.48.58 606 Similar to the pure mode I problem 1 A can be obtained from  FE v at opt r using Eqn. (14). 1 B can be obtained from  FE u at two radii (   op opt N r r L and     op op op N r r r L ) using Eqn. (17).  op r can be considered as 0.002 for calculating the mode II NSIFs [29]. The normalized mixed mode (I/II) NSIFs obtained using the PSDT are listed in Tab. (3). Once again, the results obtained from the present method show a good agreement with the published results for various  and  . The results in Tab. (3) show that using PSDT by the mere substitution of FE NOD and NSD at the optimal points accurate values of mixed mode (I/II) NSIFs can be obtained.         I F II F Present Chen [12] Present Chen [12] 15 0 2.7108 – 0.3970 – 30 2.7507 2.7670 0.5468 0.5410 60 2.8790 2.8870 0.7764 0.7660 90 3.2257 3.2300 1.1220 1.1160 30 0 2.0399 – 0.7122 – 30 2.5315 2.5460 1.0190 1.0100 60 2.6447 2.6530 1.4619 1.4280 90 2.9587 2.9640 2.0576 2.0950 45 0 2.1792 – 1.0078 – 30 2.2039 2.2170 1.3615 1.3520 60 2.2937 2.3040 1.9383 1.9110 Table 3: Normalized NSIFs I F and II F for the ASENT specimen (  0.5 a w ). Example 3: Mixed Mode Example of a Sharp V-notched Brazilian Disc (SV-BD) A sharp V-notched Brazilian Disc (SV-BD) as shown in Fig. (5) is considered as the fourth example for analyzing mixed mode (I/II) problem. The radius of the SV-BD is taken as  60 R and a compressive loading  1.0 F is applied as shown in Fig. (5). The notch length to radius ratio  0.5 a R , notch inclination angles   0º, 10º, 20° and 30° and notch angles   30°, 60°, and 90° are considered for determining the mixed mode NSIFs for the SV-BD. A Poisson’s ratio   0.25 and Young’s modulus  1 E are considered. The boundary conditions used for the FE analysis are shown in Fig. (5a). Fig. (5b) shows the typical mesh used for the SV-BD (NE=1833 and NN=5643). Fig. (5c) shows the enlarged portion near the notch tip. Figure 5: (a) Sharp V-notched Brazilian Disc (SV-BD), (b) typical FE mesh used for the SV-BD specimen (NE= 1833 , NN= 5643 ) and (c) mesh arrangement near the notch tip portion.