Ratcheting of Stainless Steel 304 Under Multiaxial Nonproportional Loading

Abstract

Multiaxial ratcheting is often simulated by use of nonlinear kinematic hardening models, while in reality materials show cyclic hardening/softening and additional hardening under nonproportional loading. The effect of isotropic hardening on ratcheting needs to be addressed in simulation. In this study, ratcheting tests are conducted on stainless steel 304 under uniaxial, torsional, and combined axial-torsional loading. The ratcheting strain is predicted based on the constitutive theory that incorporates a modified Ohno–Wang kinematic hardening rule and Tanaka’s isotropic hardening model. The results show that the main features of the stress-strain response can be simulated with the constitutive model. Ratcheting strain under axial mean stress depends highly on the loading path and load level, and the degree of cyclic changes in shear stress under torsional strain control is not as influential. The torsional ratcheting strain under mean shear stress with (or without) fully reversed axial strain cycling is found close to the axial ratcheting strain under equivalent mean stress with (or without) torsional strain cycling. In all, the experimental and predicted ratcheting strains for nonproportional paths are found in decent correlation. However, overprediction still prevails for some loading paths, and ratcheting rates deviate considerably from experimental values.

Ratcheting of 304 Stainless Steel Alloys subjected to Stress‐Controlled and mixed Stress‐ and Strain‐Controlled Conditions evaluated by Kinematic Hardening Rules

“…The C-J-K model, employing this value for other loading paths B2-B5, improved the overestimation predicted earlier by the O-W model. The predicted ratcheting curves for loading paths B1 and B4 were found in good agreements with experimental data reported by Kim et al 51 The C-J-K model with the same multiaxial factor χ i showed a noticeable deviation of predicted ratcheting curves for paths B2, B3 and B5. The ratcheting of B6 sample predicted by the C-J-K showed some underestimation in consistent with what reported by Abdel-Karim.…”

“…Table 1 presents ratcheting tests and loading conditions for tubular SS304 samples taken from. [49][50][51] In Fig. 3, loading path A1 corresponds to shear stress cycle applied in the presence of a constant axial stress.…”

“…Many researchers have investigated ratcheting response of various materials tested under stress-controlled conditions. [2][3][4][5][6][7][8][9][10][11][12] Several cyclic plasticity models have been developed to characterize ratcheting response of materials under various loading conditions. The coupled kinematic hardening rules consisted of the linear strain hardening, and dynamic recovery terms have been mainly constructed on the basis of Armstrong-Frederick (A-F).…”

Capturing yield surface evolution with a multilinear anisotropic kinematic hardening model

“…However, for at least some hardening materials, upon plastic straining in one direction the measured yield surface not only translates due to kinematic hardening, but also changes its shape. This change of shape has been observed by many authors in different metals, see Theocaris and Hazell (1965), Kuwabara et al (2000), Ishikawa (1997), Ishikawa and Sasaki (1989), Khan et al (2009Khan et al ( ), 2010a, 2010b); Hu et al (2015); 2014), Wu and Yeh (1991), Wu (2003), Sung et al (2011), Kim et al (2009), Rousset (1985), Rousset and Marquis (1985), Benallal and Marquis (1987), among others. As observed in these experiments, the actual shape of the measured yield surface depends on several factors as the material itself, the amount of prestress, and the permanent plastic strain (probing strain) after which the onset of plasticity (i.e.…”

A comparative study in descriptions of coupled kinematic hardening rules and ratcheting assessment over asymmetric stress cycles

“…The effect of loading complexities on ratcheting response of materials was studied in literature. 22,[32][33][34][35][36][37][38][39][40][41][42][43] Hassan et al 38,44,45 argued the competence of hardening rules to address ratcheting response of materials undergoing complex loading spectra. The influence of loading steps and magnitude on ratcheting of a number of steel alloys was studied by Paul et al 46,47 and Kang et al 34,[48][49][50][51] Goodman 52 discussed how influential the effect of increase in mean stress at a constant stress amplitude on ratcheting magnitude in SS316 samples is.…”