scholarly journals Investigation and Compensation of Biaxial Pre-strain During the Standard Nakajima- and Marciniak-test Using Generalized Forming Limit Concept

2017 ◽  
Vol 207 ◽  
pp. 568-573 ◽  
Author(s):  
Wolfram Volk ◽  
Christian Gaber
Keyword(s):  
Forming Limit ◽  
Limit Concept ◽  
Marciniak Test

scholarly journals Determination of the bead geometry considering formability and stiffness effect using generalized forming limit concept (GFLC)

2016 ◽  
Vol 734 ◽  
pp. 032077
Author(s):  
Wan-Gi Cha ◽  
Sabrina Vogel ◽  
Nikola Bursac ◽  
Albert Albers ◽  
Wolfram Volk
Keyword(s):  
Forming Limit ◽  
Bead Geometry ◽  
Limit Concept

Evaluation of non-linear strain paths using Generalized Forming Limit Concept and a modification of the Time Dependent Evaluation Method

2016 ◽  
Vol 10 (3) ◽  
pp. 345-351 ◽  
Author(s):  
Christian Gaber ◽  
David Jocham ◽  
Hannes Alois Weiss ◽  
Ole Böttcher ◽  
Wolfram Volk
Keyword(s):  
Evaluation Method ◽  
Time Dependent ◽  
Forming Limit ◽  
Linear Strain ◽  
Limit Concept ◽  
Non Linear ◽  
Strain Paths

scholarly journals Comparative Investigation of the Experimental Determination of AA5086 FLCs under Different Necking Criteria

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3685
Author(s):  
Xiangrui Kong ◽  
Xingrong Chu ◽  
Chongqian Chen ◽  
Yangang Wang ◽  
Peixing Liu ◽  
...  
Keyword(s):  
Forming Limit Diagram ◽  
Comparative Investigation ◽  
Forming Limit ◽  
Forming Limit Curve ◽  
Localized Necking ◽  
Marciniak Test ◽  
Height Change ◽  
Comparative Results ◽  
Nakajima Test

The construction of a forming limit diagram (FLD) is a conventional approach to obtain limit strains and to evaluate the formability of sheet metal. Appropriate necking criteria should be applied to determine the forming limit curve (FLC) accurately. In recent years, deep research on the determination of the FLC has been carried out; meanwhile, several necking criteria have been proposed. However, the application of inappropriate necking criteria would cause deviations when determining FLCs. In this study, both Marciniak and Nakajima tests were carried out on the AA5086 aluminum sheet to make a comparative investigation of different necking criteria in the determination of FLCs. In the Marciniak test, four existing necking criteria were chosen to construct FLCs, and analyzed in detail. The well-performed time dependent and position dependent methods were selected for the Nakajima test. Meanwhile, the modified Wang method based on the height change of the adjacent points was proposed. The comparative results showed that the time and position dependent methods were relatively conservative in both experiments, while the modified Wang method could identify the onset of localized necking more accurately.

Application of a Forming Limit Concept to the Design of Powder Preforms for Forging

1975 ◽  
Vol 97 (2) ◽  
pp. 121-125 ◽  
Author(s):  
C. L. Downey ◽  
H. A. Kuhn
Keyword(s):  
Lateral Flow ◽  
Full Density ◽  
Forming Limit ◽  
Preform Design ◽  
Design Technique ◽  
Cold Forming ◽  
Limit Concept ◽  
Forging Process ◽  
Metallurgical Structure ◽  
Preform Shape

The soundness of the metallurgical structure and the associated strength of a forged powder preform material increase with increasing lateral flow during the forging process. Unconstrained lateral flow, however, enhances the possibility of fracture during deformation. In this paper, a preform design technique is presented that provides the preform shape and dimensions for forging a part to full density with a sound metallurgical structure but without fracture. The basis of the approach is a forming limit concept developed previously for cold forming processes. Application of the technique is demonstrated through design of the preform for forging a pulley blank consisting of a flange, rim and hub.

Prediction of plane-strain specimen geometry to efficiently obtain a forming limit diagram by Marciniak test

2018 ◽  
Vol 25 (5) ◽  
pp. 539-545 ◽  
Author(s):  
Qing-bao Yang ◽  
Jun-ying Min ◽  
John E. Carsley ◽  
Yuan-yuan Wen ◽  
Bernd Kuhlenkötter ◽  
...  
Keyword(s):  
Plane Strain ◽  
Forming Limit Diagram ◽  
Specimen Geometry ◽  
Forming Limit ◽  
Marciniak Test

SELF ASSESSMENT TO KNOW UNDERSTANDING MATHEMATIC CONCEPT

2018 ◽  
Vol 3 (1) ◽  
pp. 14-21
Author(s):  
Deni Iriyadi
Keyword(s):  
Qualitative Study ◽  
Qualitative Analysis ◽  
Resolution Limit ◽  
Self Assessment ◽  
Limit Concept ◽  
Research Instrument ◽  
Definition Of ◽  
The Right

This research is a qualitative study aimed to determine the students' understanding of the concept of matter limit. The subjects were students of class XI IPA 1 SMA Negeri 1 Watampone. The concept includes the definition of the limit. Data obtained using a research instrument in the form of self-assessment and then proceed with the interview subjects were selected based on the results of self-assessment has been done before. Analysis using qualitative analysis of students' understanding of the concept of the limit concept. The results of this study indicate that students' understanding of concepts some of which are not / do not understand especially regarding definitions limit. In addition students are also wrong about the resolution limit. Students who understand the concept of limit dinyakatakan them restate concepts, including examples and classify the sample to non-completion of function and limit the right results.

scholarly journals A numerical approach for the modelling of forming limits in hot incremental forming of AZ31 magnesium alloy

2021 ◽  
Author(s):  
Davide Campanella ◽  
Gianluca Buffa ◽  
Ernesto Lo Valvo ◽  
Livan Fratini
Keyword(s):  
Room Temperature ◽  
Incremental Forming ◽  
Material Model ◽  
Numerical Approach ◽  
Forming Limit ◽  
Material Strength ◽  
Wall Angle ◽  
Analytical Expression ◽  
The Poor ◽  
Specific Material

AbstractMagnesium alloys, because of their good specific material strength, can be considered attractive by different industry fields, as the aerospace and the automotive one. However, their use is limited by the poor formability at room temperature. In this research, a numerical approach is proposed in order to determine an analytical expression of material formability in hot incremental forming processes. The numerical model was developed using the commercial software ABAQUS/Explicit. The Johnson-Cook material model was used, and the model was validated through experimental measurements carried out using the ARAMIS system. Different geometries were considered with temperature varying in a range of 25–400 °C and wall angle in a range of 35–60°. An analytical expression of the fracture forming limit, as a function of temperature, was established and finally tested with a different geometry in order to assess the validity.

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