PSI - Issue 13

Yuki Nishizono et al. / Procedia Structural Integrity 13 (2018) 1817–1827 —‹ ‹•Š‹œ‘‘ Ȁ –”—…–—”ƒŽ –‡‰”‹–› ”‘…‡†‹ƒ ͲͲ ሺʹͲͳͺሻ ͲͲͲ – ͲͲͲ

͸

1822

Table 5. Results of the preliminary experiments. No. T 0 [kN]

Stroke [mm]

[ °C ] -55 -50

[mm]

1 2 3 4 5 6 7 8 9

45.8 41.5 36.5 44.0 38.9 39.0 46.1 47.2 49.7 50.9 48.5 48.6 41.3 46.5

4.14 2.75 2.19 12.7 2.35 2.79 2.76 11.5 4.02 4.82 3.05 3.04 1.90 11.6

12.5 11.5

-45 -40 -65 -70 -60 -60 -65 -70 -80 -90

9.5

(6+)15

14.5 15.5

14

(4+)17

16 17

10 11 12 13 14

17.5 18.5

-100

20

-60

(4+)16.5

Specimen No.3

Specimen No.5

Fig. 5. Fracture surface after heat-tint.

Fig. 6. Relationship between test temperature and arrested crack length. 3.3. Arrest toughness evaluation by Figure 7 shows the generals of dynamic 3D elasto-plastic FEM model simulating the preliminary experiments. Brittle crack propagation is simulated by the nodal force release method and the nodal force along crack front decreases linearly to 0 in each step of time (Kobayashi et al., 1977) , which is called “RAMP” method (Abaqus Theory Guide). The element length along crack propagation plane is set to be 0.1 mm . The three-point bend jigs are modelled as analytical rigid whose curvature is equal to the jigs used in the preliminary experiments. The bend load is controlled by applying a forced