A constitutive model for various structural steels considering shared hysteretic behaviors

A unified constitutive model for structural steels is proposed to reproduce commonly observed hysteretic behaviors that are not represented effectively by current models. This model utilizes a concise description of the Bauschinger effect and a virtual boundary surface to formulate a mathematically improved evolution rule for the hardening behavior in the re-yielding and the subsequent stagnation stage. The model includes an explicit discrete update formulation to describe strain range dependence, in a manner that does not require iterative solution. Based on the existing experimental results, this model considers three cyclic mechanisms resulting in the variation of size of the stress boundary surface in different loading histories. For a better description of cyclic behaviors, two new plastic internal variables are proposed to determine the growth of saturated stress in fixed strain range and its temporary decrease under intermediately reverse deformation. For facilitating calibration, evolution rules for this model are established as set of independent equations that may be calibrated separately. Based on the calibrated parameters, the simulation results of proposed model show remarkable agreement with monotonic as well as cyclic testing data of three different steel grades with various measured strength, particularly in the case of irregular loading histories. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

A unified constitutive model for structural steels is proposed to reproduce commonly observed hysteretic behaviors that are not effectively represented by current models. The model utilizes a concise description of the Bauschinger effect and a virtual boundary surface to formulate a mathematically improved evolution rule for hardening behavior, considering three cyclic mechanisms and two new plastic internal variables. Simulation results show remarkable agreement with testing data of different steel grades, particularly in the case of irregular loading histories.