PSI - Issue 23

Atri Nath et al. / Procedia Structural Integrity 23 (2019) 263–268 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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present methodology, while that for Bari and Hassan (2000) is 15% and that for Ramezansefat and Shahbeyk (2015) is 23%.

Bari & Hassan, 2000

 a =229.5 MPa

Ramezansefat & Shahbeyk, 2015

 a =221.5 MPa

Present work

 a =209.3 MPa

 m = 44.8 MPa

 a =195.1 MPa

 -control

0

5

10

15

20

25

F error %

CS1026 steel

(a)

(b)

(c)

Fig. 1: Application of the suggested methodology to CS1026 steel for a) strain-controlled (Nath et al., 2019) b) ratcheting (Nath et al., 2019) c) accuracy estimation using F error

Paul et al. (2010) considered a modified kinematic hardening model (neglecting isotropic hardening) to simulate the behavior of SA333 steel under various cyclic loading conditions. The experimental results and the numerical simulations for SA333 steel reported by Paul et al. (2010) have been compared against the predictions for the different cyclic loading states using the CIKH model parameters (Table 2) in Fig. 2b-c. The results in Fig. 2 indicate that the suggested methodology is potential enough to replicate the experimental cyclic-plastic response of SA333 steel better than that predicted by Paul et al. (2010); the maximum value of F error for the present methodology (Fig. 2d) is 1.5% compared to 2.2% computed for that using the approach by Paul et al. (2010). The predicted monotonic behavior (Fig. 2a) obtained by the suggested approach is also in close agreement with the typical experimental behavior for SA333 C-Mn steel as reported by Sivaprasad et al. (2010).

Paul et al., 2010

Present work

 -control  a =270 MPa  a =290 MPa  a =310 MPa

 m = 80 MPa

0.0 0.5 1.0 1.5 2.0 F error %

SA333 C-Mn steel

(a)

(b)

(c)

(d)

Fig. 2: Application of the suggested methodology to SA333 C-Mn steel for a) monotonic b) strain-controlled (Nath et al., 2019) c) ratcheting (Nath et al., 2019) d) accuracy estimation using F error

Kan et al. (2011) reported that TA16 titanium alloy is a cyclically stable material; the stress amplitude was found to remain almost constant under symmetric strain-controlled cyclic loading for this material. The simulated monotonic and cyclic-plastic response obtained using the suggested methodology are compared with the reported experimental observations (Kan et al., 2011) for TA16 alloy in Fig. 3a-c. The predictions by Kourousis (2013) for the strain controlled hysteresis loop and the ratcheting strain are also included in Fig. 3b and Fig. 3c respectively for the sake of comparison. The reported predictions by Kourousis (2013) for the response of the TA16 alloy surprisingly considered yield stress of 300 MPa, while the yield stress obtained from the reported monotonic behavior is 420 MPa for the material. The current study considers the yield stress as that obtained from the reported (Kan et al., 2011) monotonic stress-strain curve (i.e. 420 MPa). The simulations provided by the suggested methodology provide a better fit to the reported experimental behavior under both symmetric strain-controlled cycles and asymmetric stress-controlled cycles as indicated from the comparison of the magnitudes of F error as summarized in Fig. 3d.