PSI - Issue 2_A

Toshiyuki Meshii et al. / Procedia Structural Integrity 2 (2016) 704–711 Toshiyuki Meshii and Kenichi Ishihara / Structural Integrity Procedia 00 (2016) 000–000

707

4

20

100

0 10 20 30 40 50 60 70 80 90 100

20 Impact toughness C J/cm 2 40 60 80

Brittle fracture %

0

-100 -75 -50 -25 0 25 50 75 100 125 150 175 200

Tested Temperature ℃

Fig. 2 Charpy impact test results

Fig. 3 True stress–true strain curve for EP-FEA

3. EP-FEA

The FEA model of the 0.5T SE(B) and 1T CT specimen used in the EP-FEA are shown in Fig. 4. Considering symmetry conditions, one quarter of 0.5T SE(B) specimen and 1T CT specimen containing a straight crack were analyzed, with appropriate constraints imposed on the symmetry planes, as illustrated in Fig. 4(a) and Fig. 4(b). An initial blunted notch of radius  was inserted at the crack tip. For all cases, 20-noded isoparametric three dimensional (3-D) solid elements with reduced (2 × 2 × 2) Gauss integration were employed. The material behaviour in the FEA was assumed to be governed by the J 2 incremental theory of plasticity, the isotropic hardening rule, and the Prandtl-Reuss flow rule. The piecewise linear total true stress-strain curve of the S55C steel shown in Fig. 3 was used in the EP-FEA. In the EP-FEA, the applied load P was measured as the total reaction force on the supported nodes, and each fracture load P c was determined from that of each experiment result. The J c simulated by the EP-FEA, denoted by J cFEA , was evaluated using a load-vs.-crack-mouth opening displacement diagram ( P - V g diagram), in accordance with ASTM E1820 (2006). Abaqus (2014) was used as the FEA solver.

(a) 0.5T SE(B)

(b) 1T CT

Fig. 4 EP-FEA model for (a) 0.5T SE(B) and (b) 1T CT