scholarly journals Micromechanical Modelling of the Cyclic Deformation Behavior of Martensitic SAE 4150—A Comparison of Different Kinematic Hardening Models

Metals ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 368 ◽  
Author(s):  
Benjamin Schäfer ◽  
Xiaochen Song ◽  
Petra Sonnweber-Ribic ◽  
Hamad ul Hassan ◽  
Alexander Hartmaier
Keyword(s):  
Kinematic Hardening ◽  
Three Dimensional ◽  
High Strength ◽  
Element Model ◽  
Calibration Procedure ◽  
Cyclic Stress ◽  
System Level ◽  
Strain Behavior ◽  
Hardening Models ◽  
Mean Stress Relaxation

A fundamental prerequisite for the micromechanical simulation of fatigue is the appropriate modelling of the effective cyclic properties of the considered material. Therefore, kinematic hardening formulations on the slip system level are of crucial importance due to their fundamental relevance in cyclic material modelling. The focus of this study is the comparison of three different kinematic hardening models (Armstrong Frederick, Chaboche, and Ohno–Wang). In this work, investigations are performed on the modelling and prediction of the cyclic stress-strain behavior of the martensitic high-strength steel SAE 4150 for two different total strain ratios (R ε = −1 and R ε = 0). In the first step, a three-dimensional martensitic microstructure model is developed by using multiscale Voronoi tessellations. Based on this martensitic representative volume element, micromechanical simulations are performed by a crystal plasticity finite element model. For the constitutive model calibration, a new multi-objective calibration procedure incorporating a sensitivity analysis as well as an evolutionary algorithm is presented. The numerical results of different kinematic hardening models are compared to experimental data with respect to the appropriate modelling of the Bauschinger effect and the mean stress relaxation behavior at R ε = 0. It is concluded that the Ohno–Wang model is superior to the Armstrong Frederick and Chaboche kinematic hardening model at R ε = −1 as well as at R ε = 0.

scholarly journals Internal Force on and Deformation of Steel Assembled Supporting Structure of Foundation Pit under Thermal Stress

2021 ◽  
Vol 11 (5) ◽  
pp. 2225
Author(s):  
Fu Wang ◽  
Guijun Shi ◽  
Wenbo Zhai ◽  
Bin Li ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Bending Moment ◽  
High Strength ◽  
Element Model ◽  
Internal Force ◽  
Foundation Pit ◽  
Dimensional Finite Element ◽  
Influence Of Temperature On ◽  
Scale Experiment ◽  
Three Dimensional Finite Element

The steel assembled support structure of a foundation pit can be assembled easily with high strength and recycling value. Steel’s performance is significantly affected by the surrounding temperature due to its temperature sensitivity. Here, a full-scale experiment was conducted to study the influence of temperature on the internal force and deformation of supporting structures, and a three-dimensional finite element model was established for comparative analysis. The test results showed that under the temperature effect, the deformation of the central retaining pile was composed of rigid rotation and flexural deformation, while the adjacent pile of central retaining pile only experienced flexural deformation. The stress on the retaining pile crown changed little, while more stress accumulated at the bottom. Compared with the crown beam and waist beam 2, the stress on waist beam 1 was significantly affected by the temperature and increased by about 0.70 MPa/°C. Meanwhile, the stress of the rigid panel was greatly affected by the temperature, increasing 78% and 82% when the temperature increased by 15 °C on rigid panel 1 and rigid panel 2, respectively. The comparative simulation results indicated that the bending moment and shear strength of pile 1 were markedly affected by the temperature, but pile 2 and pile 3 were basically stable. Lastly, as the temperature varied, waist beam 2 had the largest change in the deflection, followed by waist beam 1; the crown beam experienced the smallest change in the deflection.

Generation of Cyclic Stress-Strain Curves for Sheet Metals

2000 ◽  
Author(s):  
K. M. Zhao ◽  
J. K. Lee
Keyword(s):  
Constitutive Model ◽  
Kinematic Hardening ◽  
Optimization Procedure ◽  
High Strength ◽  
Cyclic Stress ◽  
Bending Moments ◽  
Sheet Metals ◽  
Stress Strain ◽  
Normal Anisotropy ◽  
Material Parameters

Abstract The main objective of this paper is to generate cyclic stress-strain curves for sheet metals so that the springback can be simulated accurately. Material parameters are identified by an inverse method within a selected constitutive model that represents the hardening behavior of materials subjected to a cyclic loading. Three-point bending tests are conducted on sheet steels (mild steel and high strength steel). Punch stroke, punch load, bending strain and bending angle are measured directly during the tests. Bending moments are then computed from these measured data. Bending moments are also calculated based on a constitutive model. Normal anisotropy and nonlinear isotropic/kinematic hardening are considered. Material parameters are identified by minimizing the normalized error between two bending moments. Micro genetic algorithm is used in the optimization procedure. Stress-strain curves are generated with the material parameters found in this way, which can be used with other plastic models.

scholarly journals EFFECT OF SLIDING AND HAMMERING CONTACT FOR CRACK GENERATION AND FRACTURE TOUGHNESSS IN SCRATCH TEST

2020 ◽  
Vol 57 (6A) ◽  
pp. 70
Author(s):  
Hoa Cong Vu
Keyword(s):  
Three Dimensional ◽  
Element Model ◽  
Scratch Test ◽  
Contact Forces ◽  
Adhesion Properties ◽  
Strain Behavior ◽  
Crack Generation ◽  
Dimensional Finite Element ◽  
Contact Situation ◽  
Three Dimensional Finite Element

Scratch test is one of widely used, fast, and effective methods to obtain the critical loads that are related to adhesion properties of coating. The contact situation in a scratch tester is the combination of the hammering and sliding contact. Due to the increasing load of the stylus over an elastic-plastic zone, the surface defect will occur and lead to the creation of some first visible angular cracks in the coating. As a result, this phenomenon will affect to the crack generation and failure mechanism. A three-dimensional finite element model (FEM) for describing the stress-strain behavior under stylus loading was built to get the explain the effect of contact forces for the fracture mechanism.

Effects of Reeling on Pipe Structural Performance—Part II: Analysis

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Yafei Liu ◽  
Stelios Kyriakides ◽  
Jyan-Ywan Dyau
Keyword(s):  
3D Model ◽  
Kinematic Hardening ◽  
Three Dimensional ◽  
Element Model ◽  
External Pressure ◽  
Structural Performance ◽  
Collapse Pressure ◽  
Reverse Loading ◽  
Tension Loading ◽  
Different Levels

Part II presents two modeling schemes for simulating the reeling/unreeling of a pipeline, with the aim of establishing the degrading effect of the process on the structural performance of the pipeline. A three-dimensional (3D) finite element model of the winding/unwinding of a long section of pipeline onto a rigid reel is presented first. The second model applies the curvature/tension loading history experienced at a point to a section of pipe in contact with a rigid surface of variable curvature. Both models use nonlinear kinematic hardening plasticity to model the loading/reverse loading of the material. The 3D model first demonstrates how the interaction of the problem nonlinearities influences the evolution of deformation and load parameters during reeling/unreeling. The two models are subsequently used to simulate the three-reeling/unreeling cycle experiments under different levels of back tension in Part I. The ovality-tension and axial elongation-tension results are reproduced by both models with accuracy for the first cycle, adequately for the second cycle, and are overpredicted for the third cycle. The two models are also used to simulate the reeling/unreeling followed by collapse of the tubes under external pressure experiments. Both models reproduce the measured ovality-tension results and the corresponding collapse pressures accurately. Since the two-dimensional (2D) model is computationally much more efficient, it is an attractive tool for estimating the effect of reeling on collapse pressure. Questions that require exact tracking of the winding/unwinding history and the interaction of the pipe with the reel are best answered using the 3D model.

scholarly journals A study on spring-back in U-draw bending of DP350 high-strength steel sheets based on combined isotropic and kinematic hardening laws

2018 ◽  
Vol 10 (9) ◽  
pp. 168781401879743 ◽  
Author(s):  
Van-Canh Tong ◽  
Duc-Toan Nguyen
Keyword(s):  
Process Parameters ◽  
High Strength Steel ◽  
Numerical Models ◽  
Kinematic Hardening ◽  
High Strength ◽  
Transient Behavior ◽  
Element Model ◽  
Benchmark Problems ◽  
Spring Back ◽  
Draw Bending

In this article, a numerical model for predicting spring-back in U-draw bending of DP350 high-strength steel sheet was presented. First, the hardening models were formulated based on combined isotropic–kinematic hardening laws, along with the traditional pure isotropic and kinematic hardening laws. A simplified method was proposed for determining the material parameters. Comparison of stress–strain curves of uniaxial tests at various pre-strains predicted by the numerical models and experiment showed that the combined isotropic–kinematic hardening model could accurately describe the Bauschinger effect and transient behavior subjected to cyclic loading conditions. Then, a finite element model was created to simulate the U-draw bending process using ABAQUS. Simulations were then conducted to predict the spring-back of DP350 high-strength steel in U-draw bending with geometry provided in the NUMISHEET’2011 benchmark problems. It was shown that the predictions of spring-back using the proposed model were in good agreement with the experimental results available in the literature. Finally, the effects of various tool and process parameters such as punch profile radius, die profile radius, blank holding force, and punch-to-die clearance on the spring-back were investigated. The simulation results suggested the significance of tool and process parameters on the final shape of the formed parts influenced by the spring-back.

Effects of Hardening Models on CUO Forming and Springback Simulation of High Strength Line Pipes

2015 ◽  
Vol 817 ◽  
pp. 8-13 ◽  
Author(s):  
Qiang Ren ◽  
Tian Xia Zou ◽  
Da Yong Li
Keyword(s):  
Bauschinger Effect ◽  
Oil And Gas ◽  
Kinematic Hardening ◽  
High Strength ◽  
Isotropic Hardening ◽  
Forming Process ◽  
Hardening Model ◽  
Hardening Models ◽  
Combined Hardening ◽  
Springback Prediction

The UOE process is an effective approach for manufacturing the line pipes used in oil and gas transportation. During the UOE process, a steel plate is crimped along its edges, pressed into a circular pipe with an open-seam by the successively U-O forming stages. Subsequently, the open-seam is closed and welded. Finally, the welded pipe is expanded to obtain a perfectly round shape. In particular, during the O-forming stage the plate is suffered from distinct strain reversal which leads to the Bauschinger effect, i.e., a reduced yield stress at the start of reverse loading following forward strain. In the finite element simulation of plate forming, the material hardening model plays an important role in the springback prediction. In this study, the mechanical properties of API X90 grade steel are obtained by a tension-compression test. Three popular hardening models (isotropic hardening, kinematic hardening and combined hardening) are employed to simulate the CUO forming process. A deep analysis on the deformation and springback behaviors of the plate in each forming stage is implemented. The formed configurations from C-forming to U-forming are almost identical with three hardening models due to the similar forward hardening behaviors. Since the isotropic hardening model cannot represent the Bauschinger effect, it evaluates the higher reverse stress and springback in the O-forming stage which leads to a failure prediction of a zero open-seam pipe. On the contrary, the kinematic hardening model overestimates the Bauschinger effect so that predicts the larger open-seam value. Specifically, the simulation results using the combined hardening model show good agreement in geometric configurations with the practical measurements.

Tension-Compression Tests for Springback Prediction of AHS Steel Using the Yoshida-Uemori Model

2017 ◽  
Vol 728 ◽  
pp. 78-84
Author(s):  
Weerapong Julsri ◽  
Surasak Suranuntchai ◽  
Vitoon Uthaisangsuk
Keyword(s):  
Elastic Recovery ◽  
Kinematic Hardening ◽  
High Strength ◽  
Cyclic Stress ◽  
Model Parameters ◽  
Structural Components ◽  
Compression Tests ◽  
Complex Shapes ◽  
Automotive Parts ◽  
Springback Prediction

In sheet metal formingprocess of automotive parts, springback effect is crucial, in particular, foradvanced high strength (AHS) steels. Most structural components of new vehiclesshow very complex shapes that require multi–step forming procedures.Therefore, finite element (FE)simulation has been often used to describe plasticdeformation behavior and springback occurrence of formed metal sheets.Recently, the kinematic hardening Yoshida–Uemorimodel has showed great capability for predicting elastic recovery of material. In this work, the AHSsteel grade JSC780Y wasinvestigated, in which tension–compressiontests were carried out. From resulted cyclic stress–strainresponses, material parameters were identified using different fitting methods.Determined model parameters were firstly verified by using simulations of 1–elementmodel. The most appropriate parameter set was thenobtained. Finally, a Hat-Shape forming test was performed and springback waspredicted and compared with experimental results.

A Constitutive Model for the Simulation of the Deformation Behavior of TWIP Steels

2015 ◽  
Vol 639 ◽  
pp. 411-418
Author(s):  
André Haufe ◽  
Andrea Erhart ◽  
Alexander Butz
Keyword(s):  
Finite Element ◽  
Constitutive Model ◽  
Volume Fraction ◽  
Kinematic Hardening ◽  
Flow Behavior ◽  
Three Dimensional ◽  
High Strength ◽  
Engineering System ◽  
Twip Steels ◽  
User Friendly

Due to their high strength (tensile strength > 1GPa) in combination with an extreme ductility (failure strain 30-50%) TWinning Induced Plasticity–steels (TWIP-steels) can be considered as promising materials for the production of lightweight automotive components. The industrial application of TWIP-steels requires a fundamental experimental validation of the mechanical behavior as basis for an user-friendly but at the same time accurate constitutive framework and its implementation into commercial Finite Element codes. Related investigations and implementations in order to allow for the simulation of TWIP-steel forming processes are currently conducted within the research project “TWIP4EU”, executed as a cooperation of Fraunhofer - Institut für Werkstoffmechanik IWM in Freiburg (Germany), Salzgitter Mannesmann Forschung GmbH (Germany), Swerea KIMAB (Sweden), Faurecia Autositze GmbH (Germany / France), DYNAmore GmbH (Germany) and ESI GmbH Engineering System (Germany / France).The monotonic one-dimensional hardening behavior of TWIP-steels as a function of the twin volume fraction and dislocation density has been described by Bouaziz et al. (2008), Bouaziz et al. (2011). This model has been proven to be adequate for the description of the flow behavior of TWIP-steels and serves as basis for the constitutive model, presented here. This Bouaziz-model has been extended to a three-dimensional elasto-plastic formulation, including the influence of different loading conditions, anisotropy and kinematic hardening. The present paper deals with the implementation for solids and shells in the commercial Finite Element Code LS-DYNA®and appropriate validation simulations will be presented.

FEM Modeling of Beams Cyclic Loading Based on Ziegler-Prager and Armstrong-Frederick Kinematic Hardening Models

2011 ◽  
Vol 110-116 ◽  
pp. 2838-2846
Author(s):  
Ehsan Hashemi ◽  
Mani Sharifi ◽  
Behrooz Farshi
Keyword(s):  
Finite Element ◽  
Kinematic Hardening ◽  
Variable Stiffness ◽  
Finite Element Formulation ◽  
Element Formulation ◽  
Fem Modeling ◽  
Response Curves ◽  
Strain Behavior ◽  
Hardening Models ◽  
Incremental Step

In this investigation the behavior of classical beams are simulated by a finite element formulation of the plasticity problem under two major kinematic hardening models. Complete formulation is presented for both load and deformation controlled cases. The proposed finite element formulation uses a variable stiffness matrix in each incremental step reflecting the yield surface movement. Examples are worked out for both the Ziegler-Prager and the Armstrong-Frederick theories, to show the stress-strain behavior under cyclic symmetric and asymmetric flexural loading. The results have been graphically illustrated in plots of the response curves and are compared to the published and experimental ones. It was observed that Ziegler-Prager theory for anisotropic cases with symmetric loading predicts a ratcheting response. While the results show agreement with published ones; it was also observed that the two theories do not show similar responses of reverse plasticity or ratcheting for Euler-Bernoulli beams in all the example cases.

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