Evaluation of Methods for Estimation of Cyclic Stress-Strain Parameters from Monotonic Properties of Steels

Abstract

Abstract:Most existing methods for estimation of cyclic yield stress and cyclic Ramberg-Osgood stress-strain parameters of steels from their monotonic properties were developed on relatively modest number of material datasets and without considerations of the particularities of different steel subgroups formed according to their chemical composition (unalloyed, low-alloy, and high-alloy steels) or delivery, i.e., testing condition. Furthermore, some methods were evaluated using the same datasets that were used for their development. In this paper, a comprehensive statistical analysis and evaluation of existing estimation methods were performed using an independent set of experimental material data compriseding 116 steels. Results of performed statistical analyses reveal that statistically significant differences exist among unalloyed, low-alloy, and high-alloy steels regarding their cyclic yield stress and cyclic Ramberg-Osgood stress-strain parameters. Therefore, estimation methods were evaluated separately for mentioned steel subgroups in order to more precisely determine their applicability for the estimation of cyclic behavior of steels belonging to individual subgroups. Evaluations revealed that considering all steels as a single group results in averaging and that subgroups should be treated independently. Based on results of performed statistical analysis, guidelines are provided for identification and selection of suitable methods to be applied for the estimation of cyclic stress-strain parameters of steels.

Estimation of Low-Cycle Fatigue Curves of High-Strength and Welded Steel 10CrNi3MoV

“…For comparison, UML and modified universal slope method gives very similar value -0.58, -0.56 respectively for other types of steel [1]. In [2] was shown that dividing materials to the groups (unalloyed, low-alloyed, high-alloyed) can at least bring correct estimation of the cyclic properties. Similar conclusion was drawn for ferritic steel in [16].…”

“…2b shows results for its undermatched weld. Low-cycle fatigue curves are computed following [2,4,8] as:…”

“…Low-cycle prediction is based on strain-based fatigue analysis and it is based usually on uniaxial tests [1]. However, these tests are time and cost expensive [1][2]. The situation is even more complicated in case of multiaxial [1] and non-proportional loading [3].…”

“…Hence, there was an effort to estimate fatigue properties from simple tensile data by developing methods like the four-point method, universal slope method, the uniform material law (UML) or four-point correction methodsummarization can be found for instance in [4]. Recently, there was an attempt to estimate multiaxial life prediction in absence of any fatigue properties [5] or in a fact statistical evaluation of cyclic-stress strain parameters from monotonic properties of steel [2] that have influence on estimation of fatigue properties as it will be shown further in the paper.…”

Study on Hysteresis Model of Welding Material in Unstiffened Welded Joints of Steel Tubular Truss Structure

“…Besides, the difference between the Chaboche model and the Ramberg-Osgood model in simulating and analyzing the cyclic loading characteristics of low alloy 42CrMo steel was compared and analyzed by Basan et al [37],which showed that the two models have similar results on the premise of stable material performance. In recent years, the Ramberg-Osgood model has been adopted in other research to describe the stress-strain constitutive relation of metallic materials [38][39][40][41][42].…”