PSI - Issue 13

Shuai Wang et al. / Procedia Structural Integrity 13 (2018) 1940–1946 Author name / StructuralIntegrity Procedia 00 (2018) 000 – 000

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respectively set on the sample. During the simulation, the left fixed hole is fully constrained, and the stretching process of the sample is completed by moving the loading hole to the right. A displacement of 5 mm is applied to the sample to ensure that the stress of the material exceeds the yield stress. The geometric model as shown in Fig.4.

F

Fixing holes

Loading holes

Fig.4 Geometric modeling

3.3. Mesh Model A 3D mesh model was designed to simulate the specimen as shown in Fig.5. The geometrical parameters are shown in Fig.1. A uniform tensile stress is applied to the loading hole of the specimen. To obtain a more detail and accurate data, the mesh on gauge length region of specimen is significantly refined, and the total mesh number of global model is 2988.

Fig.5 The finite model of plate tensile specimen

4. Results and discussion 4.1. Experimental results The relationship between engineering stress and strain for plate tensile specimens of 316L austenitic stainless steel at different cold work rates can be obtained using a uniaxial tensile tester, as shown in Fig.6.

600

500

400

Stress  nom /MPa

300

200

10% Cold deformation 20% Cold deformation 30% Cold deformation 40% Cold deformation

100

0

0.00

0.05

0.10

0.15

0.20

Strain  nom

Fig.6 The curve of engineering stress-strain curve with different cold deformation The data obtained in uniaxial tensile tests are usually expressed as engineering stress σ nom and strain ɛ nom . To accurately describe the change in cross-sectional area during deformation, the true stress and strain are required [16] . The conversion formula is true = (1+ ) nom nom    (2) true = ln (1+ ) nom   (3) The relationship between ture stress and strain as shown in Fig.7.