A self-optimizing inverse analysis method for estimation of cyclic elasto-plasticity model parameters

Yun, Gun Jin; Shang, Shen

doi:10.1016/j.ijplas.2010.08.003

Cited by 42 publications

(11 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We will follow this approach. In [42], a 3d optimization procedure has been developed which uses forces and displacements on the same partial boundaries. That approach generalizes the uniaxial homogeneous setting.…”

Section: • Inverse Problem: Identification Of Materials Parametersmentioning

confidence: 99%

An implicit algorithm to verify creep and TRIP behavior of steel using uniaxial experiments

et al. 2012

View full text Add to dashboard Cite

Creep is a complex material feature occurring in mechanical structures under moderate stresses and relatively high temperatures. Transformation-induced plasticity (TRIP) is a macroscopic phenomenon of steel behavior. If phase transformations occur under deviatoric stress, a permanent inelastic strain is obtained even if the yield stress is not reached. Thus, creep and TRIP do not have a yield stress like plasticity and visco-plasticity. Sometimes, during heat treatment of steel, creep and TRIP appear together. In order to determine creep or TRIP behavior it is necessary to verify concrete material laws and to determine corresponding material parameters. For this reason, often uniaxial experiments with small probes are performed in special devices. It is the main purpose of this study, to develop a procedure for the verification of possible laws for creep and TRIP and for determining material parameters, using experimental data. Therefore, an implicit algorithm in two variants will be developed: strain-driven and stress-driven. These algorithms can also be applied to simulations of (spatially homogenous) uniaxial experiments. Based on these algorithms, an optimization scheme will be developed for finding material parameters which realize a best approximation. Finally, the developed procedure will be applied for the investigation of creep and TRIP during heating of the bearing steel 100Cr6 (SAE 52100). Let the evolution equation for ξ bė( 2.22) Differentiating (2.21) with respect to time t and inserting (2.22), one gets (2.17).

show abstract

Section: • Inverse Problem: Identification Of Materials Parametersmentioning

confidence: 99%

An implicit algorithm to verify creep and TRIP behavior of steel using uniaxial experiments

et al. 2012

View full text Add to dashboard Cite

show abstract

“…Therefore, a combination of the two strategies has also been applied in the past (e.g. Chaparro et al, 2008) to improve the parameter optimisation process, while further improved optimisation strategies have also been suggested and investigated by other researchers (Sinaie et al, 2014, Yun andShang, 2011).…”

Section: Introductionmentioning

confidence: 99%

Optimising the multiplicative AF model parameters for AA7075 cyclic plasticity and fatigue simulation

Agius

Kajtaz

Kourousis

et al. 2018

AEAT

View full text Add to dashboard Cite

Purpose -This study presents the improvements of the Multicomponent Armstrong-Frederick model with Multiplier performance through a numerical optimisation methodology available in a commercial software. Moreover, it explores the application of a multi-objective optimisation technique for the determination of the parameters of the constitutive models using uniaxial experimental data gathered from Aluminium Alloy 7075-T6 specimens. This approach aims to improve the overall accuracy of stress-strain response, not only for symmetric strain controlled loading but also for asymmetrically strain-and stress-controlled loading.Design/methodology/approach -Experimental data from stress and strain controlled symmetric and asymmetric cyclic loadings have been utilised for this purpose. The analysis of the influence of the parameters on simulation accuracy has led to an adjustment scheme that can be used for focused optimisation of the MAFM model performance. The method was successfully employed to provide a better understanding of the influence of each model parameter on the overall simulation accuracy. Findings -The optimisation identified an important issue associated with competing ratcheting and mean stress relaxation objectives; highlighting the issues with arriving at a parameter set that can simulate ratcheting and mean stress relaxation for load cases not reaching at complete relaxation.Post-print: "Optimising the multiplicative AF model parameters for AA7075 cyclic plasticity and fatigue simulation", Aircraft Engineering and Aerospace Technology, Vol. 90 Issue: 2, pp.251-260, https://doi.org/10.1108/AEAT-05-2017-0119 2 Practical implications -The study uses a strain-life fatigue application to demonstrate the importance of incorporating a technique such as the presented multi-objective optimisation method to arrive at robust parameters capable of accurately simulating a variety of transient cyclic phenomena.Originality/value -The proposed methodology improves the accuracy of cyclic plasticity phenomena and strain-life fatigue simulations for engineering applications. This study is considered a valuable contribution for the engineering community, as it can act as starting point for further exploration of the benefits that can be obtained through material parameter optimisation methodologies for models of the Multicomponent Armstrong-Frederick class.

show abstract

“…the load and displacement response measured at the boundaries), and that these fields depend on the constitutive response. Other researchers [18][19][20] have identified the ill-posed nature of this problem, recognizing that it renders the calibration susceptible to non-unique parameter fits. This means that many sets of calibrated parameters may closely (or exactly) match the load-displacement data from the tests.…”

Section: Introductionmentioning

confidence: 99%

Constitutive parameter calibration for structural steel: Non-uniqueness and loss of accuracy

Cooke¹,

Kanvinde

2015

Journal of Constructional Steel Research

View full text Add to dashboard Cite

a b s t r a c tFinite element (FE) simulations used to characterize extreme limit states in steel structures require the calibration of numerous parameters. Calibration of these models for large strains (greater than 0.3 or so) cannot be performed using stress-strain curves on standard tests, since the stress state in these tests becomes non-homogenous due to necking or buckling which occur at lower strains. As a result, calibration is often performed by matching load-displacement curves of calibration specimens to those obtained through complementary FE simulations. In these situations, multiple parameter sets produce strain fields that match the measured load-displacement response, resulting in non-unique parameter fits. A series of 2400 FE simulations with 4 specimen geometries, 300 material parameters sets, and 2 loading histories indicates that multiple trial parameter sets produce excellent load-displacement match with the true material response, implying that the method is highly susceptible to nonunique fitting. All simulations use the Armstrong and Frederick constitutive model with a von Mises yield surface. The impact of non-unique fitting is assessed through FE simulations based on parameter sets that show excellent load-displacement match with calibration specimens. It is determined that the non-uniqueness does not significantly affect the prediction of peak force. However, it severely impacts the accuracy in prediction of internal plastic strains, with errors as large as 50% with respect to the true material. This has serious implications for FE simulation used to characterize extreme, strain-based limit states such as fracture. Strategies for mitigation of this inaccuracy are presented, along with limitations of the study.

show abstract

A self-optimizing inverse analysis method for estimation of cyclic elasto-plasticity model parameters

Cited by 42 publications

References 52 publications

An implicit algorithm to verify creep and TRIP behavior of steel using uniaxial experiments

An implicit algorithm to verify creep and TRIP behavior of steel using uniaxial experiments

Optimising the multiplicative AF model parameters for AA7075 cyclic plasticity and fatigue simulation

Constitutive parameter calibration for structural steel: Non-uniqueness and loss of accuracy

Contact Info

Product

Resources

About