PSI - Issue 13

Ho-Wan Ryu et al. / Procedia Structural Integrity 13 (2018) 1932–1939 Author name / Structural Integrity Procedia 00 (2018) 000 – 000

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C(T) simulations. Parametric study results on Q and  3 parameter were described in Fig. 6(b) and (c). Increasing Q value increases the peak loads in tensile region and decreases those in compression side. Besides, increasing  3 value decrease the peak loads in both tensile and compression regions. From these results, final parameters to precisely predict a deformation behavior in cyclic C(T) simulation was summarized in Table 4 for two materials and two load ratios. Simulation results from determined parameters are shown in Fig. 7.

(a) (c) Fig. 6. Comparison of FE simulation results using combined hardening model with experimental cyclic fracture toughness test data of SA312 TP316L SS and R =-1.0. (b)

(a) (b) Fig. 7. Comparison of FE simulation results using combined hardening model with experimental cyclic fracture toughness test data of (a) SA312 TP316L SS ( R =-0.5) and (b) CF8A CASS ( R =-1.0).

Table 4. Finally determined combined hardening parameters of SA312 TP316 SS and CF8A CASS.  o C 1  1 C 2  2 C 3  3 Q b SA312 TP316 (R=-0.5) 116 114783 2000 29935 262 1049 2 178 5.76 SA312 TP316 (R=-1.0) 116 114783 2000 29935 262 1049 10 148 5.76 CF8A (R=-1.0) 105 217389 2000 29298 228 1582 10 111 7.15

5. Conclusions

This paper presents the determination procedure of parameters in combined hardening model based on limited material test data. The effect of parameters were explained and proper parameters were determined to accurately simulate a deformation behavior of cyclic fracture toughness test with incremental loading sequence. The parameters of isotropic hardening model were derived from the difference between monotonic and cyclic stress versus strain curves, whereas the parameters of nonlinear kinematic hardening model were derived from hysteresis loop data from