PSI - Issue 68

Rintaro Tsuda et al. / Procedia Structural Integrity 68 (2025) 674–680 R. Tsuda et al. / Structural Integrity Procedia 00 (2025) 000–000

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that the ratio α has a linear relationship with the volume fraction of the inclusion phase while the inclusion volume fraction range is from 0.05 to 0.40, regardless of the material constitutive equation of the inclusion phase. Therefore, it is assumed that α can be expressed in the form of Eq. (4) using the volume fraction f of the inclusion phase. (4) Under this assumption, the convergence calculation shown in Fig. 6 was solved using the python code. h = 0.02 and g = 0.33 were appropriate at 173K h = -0.19 and g = 1.1 were appropriate at 20K. The coefficients of the constitutive equation in the form of Eq. (1) are ! = 946[MPa], ! = 0.0675, ! =0.38 for the γ phase, which is the matrix phase, and " = 5431[MPa], " = 0.0035, " =0.49 for the α' phases at 173K. And ! = 2032[MPa], ! = 0.0021, ! =0.29 for the γ phase, which is the matrix phase, and " = 4167[MPa], " = 0.0436, " =0.8 for the α' and ε composite phases at 20K. 6. Simulation of tensile test In order to confirm that the developed FEM module works well, model calculations of tensile tests conducted at 20 K and 173K were performed to check the agreement with the experimental data. In addition to using the elasto-plastic FEM module developed in this study, the material constants for isotropic materials are Young's modulus of 206 GPa and Poisson's ratio of 0.3. The elements used were two-dimensional axisymmetric solid elements. Tensile tests with upward displacement at the top of the specimen were simulated. Fig. 3 shows the true stress-true strain relationship of the composite phases. It can be seen that the experimental results are in good agreement with the simulation results. The relation between the true strain of the composite phase and the stress of the single phase, which can be obtained directly from the experiment, is shown in Fig. 3. Here, too, there is a good agreement with the experimental results.