Graphical method based on modified maximum force criterion to indicate forming limit curves of 22MnB5 boron steel sheets at elevated temperatures

2021 ◽  
Author(s):  
The-Thanh Luyen ◽  
Quoc-Tuan Pham ◽  
Thi-Bich Mac ◽  
Tien-Long Banh ◽  
Duc-Toan Nguyen
Keyword(s):  
Elevated Temperatures ◽  
Graphical Method ◽  
Maximum Force ◽  
Forming Limit ◽  
Boron Steel ◽  
Steel Sheets ◽  
Force Criterion ◽  
Forming Limit Curves

Forming Limits of Several High-Strength Steel Sheets under Proportional/Non-Proportional Deformation Paths

2014 ◽  
Vol 939 ◽  
pp. 260-265 ◽  
Author(s):  
Ryutaro Hino ◽  
Satoki Yasuhara ◽  
Yutaka Fujii ◽  
Atsushi Hirahara ◽  
Fusahito Yoshida
Keyword(s):  
High Strength Steel ◽  
High Strength ◽  
Experimental Results ◽  
Forming Limit ◽  
Type Analysis ◽  
Forming Limits ◽  
Steel Sheets ◽  
Path Dependent ◽  
Forming Limit Curves ◽  
Good Agreement

Forming limits of several high-strength steel (HSS) sheets under non-proportional deformation paths were examined experimentally and predicted analytically. Forming limit curves (FLCs) for 590MPa, 780MPa and 980MPa grade HSS sheets were obtained by performing stretch forming tests under proportional deformation and two types of non-proportional deformation. The experimental results showed strong path-dependent characteristics of FLCs of HSS sheets. Forming limits of equi-biaxially prestrained HSS sheets became markedly lower compared to the original FLCs under proportional deformation, while forming limits of uniaxially prestrained HSS sheets became partially higher than the original FLCs. It was confirmed that Marciniak-Kuczyński type analysis gave reasonably good predictions of forming limits under non-proportional deformation paths. Especially forming limit predictions of equi-biaxially-prestrained sheets showed good agreement with the corresponding experimental results.

Predictive Performances of FLC Using Marciniak-Kuczynski Model and Modified Maximum Force Criterion

2015 ◽  
Vol 651-653 ◽  
pp. 96-101 ◽  
Author(s):  
Dorel Banabic ◽  
Lucian Lazarescu ◽  
Dan Sorin Comsa
Keyword(s):  
Theoretical Models ◽  
Alloy Sheet ◽  
Maximum Force ◽  
Forming Limit ◽  
Forming Limit Curve ◽  
Experimental Procedure ◽  
Force Criterion ◽  
Yield Functions ◽  
Theoretical Predictions ◽  
The Hill

This paper is focused on the performance evaluation of two theoretical models that can be used to predict the Forming Limit Curve (FLC) for an AA6016-T4 aluminium alloy sheet. The FLC is calculated based on the Marciniak-Kuczynski (M-K) model and the Modified Maximum Force Criterion (MMFC) using the Hill '48, Barlat '89 and BBC 2005 yield criteria, the latter identified in three variants, namely with 6, 7, and 8 material parameters. The performance assessment of the M-K and MMFC models combined with different yield functions is based on the comparison between the theoretical predictions and the experimental data provided by the Nakazima test (ISO 12004: 2008) as well as by an experimental procedure recently developed by the authors for the FLC determination.

Combined numerical and experimental study to predict the forming limit curve of boron steel sheets at elevated temperatures

2019 ◽  
Vol 234 (1-2) ◽  
pp. 189-203 ◽  
Author(s):  
Nguyen Duc-Toan ◽  
Kim Young-Suk
Keyword(s):  
Ductile Fracture ◽  
Growth Model ◽  
Void Growth ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Fracture Strain ◽  
Forming Limit ◽  
Boron Steel ◽  
Limit Curve ◽  
Forming Limit Curve

The aim of this study involved evaluating and predicting forming limit curves of boron steel 22MnB5 sheet at elevated temperatures. A finite-element method simulation was adopted based on ductile fracture criteria and simple experiments at elevated temperatures. First, tensile experimental data and ductile fracture criterions of Johnson–Cook and ductile void growth models were input to ABAQUS/Explicit software to predict and compare the same with fracture occurrence in experiments performed via Hecker’s punch stretching tests at room temperature. Subsequently, punch stretching test data at room temperature were added to correct the fracture strain locus in the space of the stress triaxiality and the equivalent strain following the ductile void growth model. After confirming the accuracy of the forming limit curve prediction at room temperature, fracture strain loci at high temperatures using ductile void growth model were determined based on the average ratio between the fracture equivalent plastic strains at room temperature as well as higher temperatures. Finally, Hecker’s punch stretching tests were numerically simulated to predict forming limit curve(s) of boron steel 22MnB5 sheet at high temperatures.

A Graphical Method to Estimate Forming Limit Curve of Sheet Metals

2019 ◽  
Vol 794 ◽  
pp. 55-62 ◽  
Author(s):  
Quoc Tuan Pham ◽  
Duc Toan Nguyen ◽  
Jin Jae Kim ◽  
Young Suk Kim
Keyword(s):  
Sheet Metal ◽  
Sheet Metal Forming ◽  
Metal Forming ◽  
Graphical Method ◽  
Forming Limit ◽  
Sheet Metals ◽  
Limit Curve ◽  
Forming Limit Curve ◽  
Force Criterion ◽  
Necking Criterion

Since its foundation, the concept of forming limit diagram has been widely accepted in sheet metal forming community as a powerful tool for studying formability. There are pyramid models that were developed to estimate the forming limit curve theoretically, for example, Swift's diffuse necking criterion, Hill's localized necking criterion, Marciniak and Kuczynski model, Modified Maximum Force Criterion, etc.. Implement of these models, however, is a laborious task. To simply the task, this study presents a graphical method to estimate forming limit curve of sheet metal. Some new insights into the Modified Maximum Force Criterion, the Hora method, are discussed. The insights pertain to the use of a graphic tool to estimate limit strains at three critical forming modes in sheet metal forming that are the uniaxial tension, plane strain, and equi-biaxial tension. Connecting three points by linear lines yields to a simple graph of forming limit curve. Method validation is supported by comparing the estimated forming limit curve with experimentally measured data for several automotive sheet metals.

scholarly journals Experimental investigation of forming limit curves and deformation features in warm forming of an aluminium alloy

2016 ◽  
Vol 232 (3) ◽  
pp. 465-474 ◽  
Author(s):  
Zhutao Shao ◽  
Qian Bai ◽  
Nan Li ◽  
Jianguo Lin ◽  
Zhusheng Shi ◽  
...  
Keyword(s):  
Aluminium Alloy ◽  
Elevated Temperatures ◽  
Warm Forming ◽  
Dome Height ◽  
Forming Limit ◽  
Thickness Variation ◽  
Forming Process ◽  
Deformation Features ◽  
Forming Temperature ◽  
Forming Limit Curves

The determination of forming limit curves and deformation features of AA5754 aluminium alloy are studied in this article. The robust and repeatable experiments were conducted at a warm forming temperature range of 200 °C–300 °C and at a forming speed range of 20–300 mm/s. The forming limit curves of AA5754 at elevated temperatures with different high forming speeds have been obtained. The effects of forming speed and temperature on limiting dome height, thickness variation and fracture location are discussed. The results show that higher temperatures and lower forming speeds are beneficial to increasing forming limits of AA5754; however, lower temperatures and higher forming speeds contribute to enhancing the thickness uniformity of formed specimens. The decreasing forming speed and increasing temperature result in the locations of fracture to move away from the apexes of formed specimens. It is found that the analysis of deformation features can provide a guidance to understand warm forming process of aluminium alloys.

A Study on Modified Maximum Force Criterion to Predict Forming Limit Curve of Stainless Steel Sheet

2011 ◽  
Vol 311-313 ◽  
pp. 916-921
Author(s):  
Duc Toan Nguyen ◽  
Tien Long Banh ◽  
Dong Won Jung
Keyword(s):  
Stainless Steel ◽  
Steel Sheet ◽  
Strain Ratio ◽  
Maximum Force ◽  
Forming Limit ◽  
Stainless Steel Sheet ◽  
Limit Curve ◽  
Forming Limit Curve ◽  
Hardening Law ◽  
Force Criterion

In order to predict forming limit curve for stainless steel sheet, the modified maximum force criterion (MMFC), introduced by Hora et al (1996 A prediction method for ductile sheet metal failure in FE-simulation Proc. Numisheet’96 Conf. pp 252–256), was adopted follow Swift’s hardening law. After comparing with experimental results, the improvement of MMFC model for FLD’s prediction were proposed based on Swift’s hardening law by representing work hardening coefficient as a function of strain ratio (β). The proposed MMFC model shows in good agreement between FLD’s computational and experimental result for stainless steel sheet. The results of proposed MMFC model also show that the stress-strain curves of sheets materials are difference at each strain ratio.

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