Ratcheting behavior of pressurized 316L austenitic stainless steel pipe tee under cyclic bending using DIC method

In this study, the ratcheting behavior of a 316 L Austenitic Stainless Steel pipe tee under cyclic bending and constant internal pressure was investigated experimentally and numerically using the digital image correlation (DIC) method. First, the material of the tee was verified with chemical analyses. During the experimental tests, bending load was applied using an INSTRON 8503 machine, a compressed air capsule was used to apply the constant internal pressure and Strain was measured using the digital image correlation (DIC) method. In the experimental tests, tee samples were tested at controlled force and room temperature (25 °C). It was observed that increasing the average force, amplitude force, and internal pressure resulted in an increased accumulation of ratcheting strain. Finally, the ratcheting behavior of the tee samples was simulated using ANSYS software and the finite element method based on a nonlinear kinematic/isotropic hardening model. The FE simulation results were compared with experimental data, and it was found that the numerical data are in good agreement with experimental data.