Elastoplastic model of metals with smooth elastic–plastic transition

Abstract

The subloading surface model is based on the simple and natural postulate that the plastic strain rate develops as the stress approaches the yield surface. It therefore always describes the continuous variation of the tangent modulus. It requires no incorporation of an algorithm for the judgment of yielding, i.e., a judgment of whether or not the stress reaches the yield surface. Furthermore, the calculation is controlled to fulfill the consistency condition. Consequently, the stress is attracted automatically to the normal-yield surface in the plastic loading process even if it goes out from that surface. The model has been adopted widely to the description of deformation behavior of geomaterials and friction behavior. In this article, it is applied to the formulation of the constitutive equation of metals by modifying the past formulation of this model. This modification enables to avoid the indetermination of the subloading surface, to make the reloading curve recover promptly to the preceding loading curve, and to describe the cyclic stagnation of isotropic hardening. The applicability of the present model to the description of actual metal deformation behavior is verified through comparison with various cyclic loading test data.

Evaluation of the horizontal load-carrying capacity of a thin steel bridge pier by means of the Damage Subloading Surface model

“…The choice of an unconventional plasticity model is due to the ability of the S-S model to catch a realistic accumulation of plastic deformation during cyclic loading, as shown in [11,12], or in fatigue life investigations [13,14,17]. Briefly, a new surface, i.e.…”

Ductile damage evolution law for proportional and non-proportional loading conditions

“…The choice of an unconventional plasticity model [17] is mainly due to the ability of the SS theory to give a realistic description of the plastic strain accumulation and of the material ratcheting for cyclic mobility problems and for fatigue life investigations. In fact, this approach has been used successfully in different numerical analyses focused on predicting low-and high-cycle fatigue life [18,19], assessing welded structures [20,21], and generally for analyzing the deformation behavior of metallic [22,23] and granular [24][25][26] The main feature of the SS consists in the abolition of the neat distinction between the elastic and plastic domains, stating that irreversible deformations can be generated whenever the loading criterion is satisfied. In order to achieve this goal a second surface, named subloading surface, is generated by means of a similarity transformation from the conventional yield surface, here renamed normal yield-surface (see Fig.…”

“…The parameters T 1 , T 2 and T3 were calibrated during the pier analysis. The material constants c, χ, u, Re regulate the amount of inelastic strain in the sub-yield state and, in general, are calibrated by means of a cyclic loading analysis to fit the material ratcheting [21,23,27].…”

Material models of cyclic plasticity with extended isotropic hardening: a review

“…9, at 75% drawbed penetration; comparison of experimental profile with those predicted using the isotropic hardening model (IH), combined isotropic-nonlinear kinematic hardening model (NKH+IH), and Yoshida-Uemori model (Y-U) in finite element analysis (a) without and (b) with Young's modulus degradation . been used to simulate workhardening stagnation in the framework of the subloading surface model (Hashiguchi et al, 2012;Hashiguchi, 2014). The nonhardening strain region has also been used to replace the nonhardening stress region in the Y-U model so as to improve the model (Jia and Kuwamura, 2014;Jia, 2014).…”