Comparison Between Two Experimental Procedures for Cyclic Plastic Characterization of High Strength Steel Sheets

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
G. B. Broggiato ◽  
F. Campana ◽  
L. Cortese ◽  
E. Mancini
Keyword(s):  
Sheet Metal ◽  
High Strength Steel ◽  
Kinematic Hardening ◽  
High Strength Steels ◽  
High Strength ◽  
Bending Test ◽  
Compression Tests ◽  
Element Analysis ◽  
Constitutive Parameters ◽  
Springback Prediction

In finite element analysis of sheet metal forming the use of combined isotropic-kinematic hardening models is advisable to improve stamping simulation and springback prediction. This choice becomes compulsory to model recent materials such as high strength steels. Cyclic tests are strictly required to evaluate the parameters of these constitutive models. However, for sheet metal specimens, in case of simple axial tension-compression tests, buckling occurrence during compression represents a serious drawback. This is the reason why alternative set-ups have been devised. In this paper, two experimental arrangements (a cyclic laterally constrained tension-compression test and a three-point fully reversed bending test) are compared so as to point out the advantages and the disadvantages of their application in tuning the well-known Chaboche’s hardening model. In particular, for tension-compression tests, a new clamping device was specifically designed to inhibit compressive instability. Four high strength steel grades were tested: two dual phases (DP), one transformation induced plasticity (TRIP) and one high strength low alloy material (HSLA). Then, the Chaboche’s model was calibrated through inverse identification methods or by means of analytical expressions when possible. The proposed testing procedure proved to be successful in all investigated materials. The achieved constitutive parameters, obtained independently from the two experimental techniques, were found to be consistent. Their accuracy was also been assessed by applying the parameter set obtained from one test to simulate the other one, and vice versa. Clues on what method provides the better transferability are given.

scholarly journals Springback Prediction of Stretching Process using Finite Element Analysis for DP600 Steel Sheet

2017 ◽  
Vol 11 (1) ◽  
pp. 5-8
Author(s):  
Jan Slota ◽  
Ivan Gajdos ◽  
Emil Spišák ◽  
Marek Šiser
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
High Strength Steel ◽  
Steel Sheet ◽  
Kinematic Hardening ◽  
High Strength ◽  
Compression Tests ◽  
Element Analysis ◽  
Hardening Models ◽  
Springback Prediction

Abstract Springback phenomenon is well predicted for some mild steel materials, but not for steels with higher strength. One of the most used tools to stamping optimization is usage of finite element analysis. In order to accurate describe the real behaviour of the materials for stamping of vehicle panels, the application of proper hardening rule seems to be crucial. Due to higher accuracy of predicted results, high strength steel sheets are usually modelled by means of kinematic or mixed isotropic-kinematic hardening models. In this paper the springback prediction of advanced high strength steel DP600 by numerical simulation was investigated. Through cyclic tension-compression tests, the material characterization has been performed for DP600 steel sheet. Different hardening models (isotropic, kinematic and mixed isotropic-kinematic) used in the simulations were compared with expreriment. The Yoshida–Uemori model succesfully describe the kinematic behaviour of the material and provided more accurate results than others.

Validation of Kinematic Hardening Parameters from Different Stress States and Levels of Plastic Strain with the Use of the Cyclic Bending Test

2015 ◽  
Vol 639 ◽  
pp. 385-392 ◽  
Author(s):  
Martin Rosenschon ◽  
Sebastian Suttner ◽  
Marion Merklein
Keyword(s):  
Kinematic Hardening ◽  
High Strength Steels ◽  
High Strength ◽  
Bending Test ◽  
Compression Tests ◽  
Cyclic Shear ◽  
Cyclic Bending ◽  
Advanced High Strength Steels ◽  
Hardening Law ◽  
Stress States

The recent development of new lightweight sheet metal materials, like advanced high-strength steels or aluminium alloys, in combination with an increasing component complexity provides new challenges to the numerical material modelling in the FEM based process design. An auspicious approach to improve the quality of the numerical results – most notably in springback analysis – is the modelling of the so called Bauschinger effect achieved through implementation of kinematic hardening models. Within this paper the influence of the stress state and the level of pre-strain on the numerical simulation result of the advanced high strength steel DP-K45/78+Z will be analysed. For this purpose, a parameter identification of the kinematic hardening law according to Chaboche and Rousselier is performed at different pre-strains on the basis of experimental data from tension-compression tests as well as cyclic shear tests. Finally, the identified parameters are validated in a comparison between numerical and experimental results of a cyclic bending test.

Finite Element Analysis of Reinforcement Rocker Part Made from JAC780Y Steel Sheets

2021 ◽  
Vol 877 ◽  
pp. 83-89
Author(s):  
Aeksuwat Nakwattanaset ◽  
Surasak Suranuntchai
Keyword(s):  
Finite Element ◽  
Sheet Metal ◽  
High Strength Steel ◽  
High Strength ◽  
Material Model ◽  
Advanced High Strength Steel ◽  
Forming Process ◽  
Element Analysis ◽  
Steel Sheets ◽  
Springback Prediction

The manufacturing industries for automotive parts aim to develop technologies for reducing vehicle weight in order to decrease fuel consumption. However, passive safety function for drivers and passengers must not be impaired or should be even improved. Therefore, advanced high strength steel sheet plays more and more important role in designing automotive components. Nowadays, prediction of formability for sheet metal stamping has high capability more than the past. The major challenge is springback prediction. Moreover, it assists in the tooling design to correctly compensate for springback. Especially in automotive production, springback effects have been generally exhibited distinct after forming process of the high strength steel sheets. The springback effect occurred in the deformed state of metal parts must be taken into account by designing any sheet metal panels. Then, the purpose of the present research is to investigate the springback phenomenon of an automotive part named Reinforcement Rocker RL made from an advanced high strength steel grade JAC780Y, after stamping. In addition, the tools design has been carried out. Finite Element (FE) program known as DYNAFORM (based on LS-DYNA solver), has been applied to analyze and improve the springback effect on such forming part. An anisotropic material model according to type 36 (MAT_036 3-PARAMETER_BARAT) was applied. The results obtained from simulations were compared with required parts in each section. Then, the die surface from compensation in 2nd step forming was modified to use. Finally, the simulation part was verified with the real stamping part. It was found that the finite element simulation showed high capability for prediction and compensation of springback in high strength steel sheets forming.

Advanced High Strength Steel Sheet Forming and Springback Simulation

2010 ◽  
Vol 97-101 ◽  
pp. 200-203 ◽  
Author(s):  
Ke Chen ◽  
Jian Ping Lin ◽  
Mao Kang Lv ◽  
Li Ying Wang
Keyword(s):  
High Strength Steel ◽  
Yield Criterion ◽  
Kinematic Hardening ◽  
Sheet Material ◽  
High Strength ◽  
Material Model ◽  
Sheet Forming ◽  
Isotropic Hardening ◽  
Advanced High Strength Steel ◽  
Springback Prediction

With the increasing use of finite element analysis method in sheet forming simulations, springback predictions of advanced high strength steel (AHSS) sheet are still far from satisfactory precision. The main purpose of this paper was to provide a method for accurate springback prediction of AHSS sheet. Material model with Hill’48 anisotropic yield criterion and nonlinear isotropic/kinematic hardening rule were applied to take account the anisotropic yield behavior and the Bauschinger effect during forming processes. U-channel forming and springback simulation was performed using ABAQUS software. High strength DP600 sheet was investigated in this work. The simulation results obtained with the proposed material model agree well with the experimental results, which show a remarkable improvement of springback prediction compared with the commonly used isotropic hardening model.

A Study of Springback of Sheet Metal Formed Parts Using ANSYS

2011 ◽  
Vol 291-294 ◽  
pp. 381-384
Author(s):  
Xuan Zhi Wang ◽  
Syed H. Masood ◽  
Daron Ng ◽  
Omar Dawwas
Keyword(s):  
Sheet Metal ◽  
Metal Forming ◽  
High Strength Steels ◽  
High Strength ◽  
Analysis Software ◽  
Element Analysis ◽  
Advanced High Strength Steels ◽  
Material Recovery ◽  
Formed Product ◽  
Forming Tools

Springback is one of main reason for inaccuracy of sheet metal formed product. Therefore prediction of springback is very important for production of precise products. Springback is an elastic material recovery after unloading of the forming tools, and causes variations and inconsistencies of final part dimensions. This is affected by various parameters involved in the process of sheet metal forming. The main aim of this paper is to investigate the springback of finished part by analysing and controlling the effects of the control parameters on the springback of advanced high strength steels (AHSS). This is done by modelling a deep-drawing process and analysing the results as determined on ANSYS finite element analysis software.

Comparison of Three Methods for Material Hardening Parameter Identification under Cyclic Tension-Compression Loadings: Roll Levelling Case Study

2015 ◽  
Vol 651-653 ◽  
pp. 957-962 ◽  
Author(s):  
Elena Silvestre ◽  
Eneko Sáenz de Argandoña ◽  
Lander Galdos ◽  
Joseba Mendiguren
Keyword(s):  
Parameter Identification ◽  
Kinematic Hardening ◽  
High Strength Steels ◽  
High Strength ◽  
Material Model ◽  
Forming Process ◽  
Element Analysis ◽  
Transient Behaviour ◽  
Cyclic Tension ◽  
Hardening Parameter

The roll levelling is a forming process used to remove the residual stresses and imperfections of metal strips by means of plastic deformations. The process is especially important to avoid final geometrical errors when coils are cold formed or when thick plates are cut by laser. In the last years, and due to the appearance of high strength materials such as Ultra High Strength Steels, machine design engineers are demanding a reliable tool for the dimensioning of the levelling facilities. In response to this demand, Finite Element Analysis is becoming an important technique able to lead engineers towards facilities optimization through a deeper understanding of the process.In this scenario, the accuracy and quality of the simulation results are highly dependent on the accuracy of the implemented material model. During roll levelling process, the sheet metal is subjected to cyclic tensile-compressive deformations, therefore a proper constitutive. model which considers the phenomena that occurs during cyclic loadings, such as the Bauschinger effec, work hardeningt and the transient behaviour, is needed. The prediction of all these phenomena which affect the final shape of the product are linked to the hardening rule.In the present paper, the roll levelling simulation of a DP1000 steel is performed using a combined isotropic-kinematic hardening formulation introduced by Chaboche and Lemaitre since its simplicity and its ability to predict the Bauschinger effect. The model has been fitted to the experimental curves obtained from a cyclic tension-compression test, which has been performed by means of a special tool developed to avoid the buckling of the specimen during compressive loadings. The model has been fitted using three different material hardening parameter identification methodologies which have been compared.

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.

scholarly journals Investigation Effect of Spring Back on Bending Test of (DP590) Dual Phase Steel

2018 ◽  
Vol 2 (6) ◽  
pp. 55-62
Author(s):  
Muhamad Sani Buang ◽  
Keyword(s):  
Sheet Metal ◽  
Dual Phase Steel ◽  
High Strength Steels ◽  
High Strength ◽  
Bending Test ◽  
Dual Phase ◽  
Spring Back ◽  
Factors Affecting ◽  
Advanced High Strength Steels ◽  
Fitting In

: The use of advanced high strength steels as a metal in sheet metal forming in automotive industry currently has been increased where Advanced High Strength Steel (AHSS) especially Dual Phase (DP590) Steels have gained a great attention due to a combination of high strength and good formability. However, one of the major constraints in forming AHSS is the occurrence of high spring back caused by elastic relaxation after loading, which causes illness-fitting in part assembly and geometric deviation of the intended design. Spring back is the main problem of defect that occurs at sheet metal after the bending process which creates problems for the parts during the assembly. This paper presents an investigation the effect of spring back on bending test of Dual Phase Steel (DP590). Punch travel and thickness are among factors affecting the spring back behavior. Various parameter value; punch radius (5mm), die radius (5mm), die gap (70mm), thickness of specimen 1mm and 2mm, punch travel/stroke (25%, 50%, 75%, 100%) from 20 mm depth, punch speed (2mm/min) and Orientation of sheet cutting, which is in rolling (00°), diagonal (45°) and transverse (90°). From the analysis of V-bending test punch travel, thickness and orientation of sheet cutting are significant factor that affecting the spring back phenomena. The result form this experiment could be useful for design engineers and manufacturing engineers to make improvement of predict the spring back behavior and also to understanding the material properties of AHSS in order to eliminate spring back and achieve good final product.

FE Simulation of Sheet Metal Forming – State of the Art in Automotive Industry

2005 ◽  
Vol 6-8 ◽  
pp. 13-18 ◽  
Author(s):  
H.J. Haepp ◽  
M. Rohleder
Keyword(s):  
Sheet Metal ◽  
Automotive Industry ◽  
Development Process ◽  
High Strength Steels ◽  
Feasibility Studies ◽  
High Strength ◽  
Element Analysis ◽  
Early Design ◽  
Metal Parts ◽  
Sheet Metal Parts

Nowadays feasibility studies using finite element analysis are performed in very early design phases of sheet metal parts forming. Further, simulation technology is used to optimize the first forming stage. Because of the ever intensifying international competition and the increased use of high-strength steels and aluminum alloys, the absorption of springback deviations is a great challenge, especially in the automotive industry. The application of numerical computation to predict springback deviations and to create compensated die designs in early design phases of sheet metal parts forming becomes essential. At DaimlerChrysler the numerically based compensation of springback deviations during the die development process of complex car parts is achieved. However, developments to optimize and compensate dies automatically or to predict form deviations on assemblies are still necessary.

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