Effect of Material Anisotropies of Hot-Rolled High-Strength Steel Sheet on Localized Deformation Behavior in Hole Expansion - Part-I Experimental Consideration to Circular and Oval Hole

In this study, the effect of the material anisotropies of hot-rolled high-strength steel sheet on localized deformation behavior in hole expansion test has been investigated experimentally. First, the hole expansion test with the circular hole has been conducted to investigate the effect of anisotropies of material properties on the localized deformation behavior around the hole edge. Next, the hole expansion test with the oval hole has been conducted to investigate the effect of the major axis direction of the oval hole on the localized deformation behavior around the hole edge. As a result, it was clarified that the effect of anisotropies of r-value and n-value on the localized deformation behavior is strong, especially the anisotropy of n-value.

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Hole Expansion Test and Characterization of High-Strength Hot-Rolled Steel Strip

Transactions of the Indian Institute of Metals ◽

10.1007/s12666-021-02458-5 ◽

2021 ◽

Author(s):

Arbind Kumar Akela ◽

D. Satish Kumar ◽

G. Balachandran

Keyword(s):

Steel Strip ◽

High Strength ◽

Rolled Steel ◽

Hole Expansion ◽

Expansion Test ◽

Hole Expansion Test ◽

Hot Rolled ◽

Hot Rolled Steel

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Description of anisotropic properties of sheet metal based on spline curves and hole expansion test simulation of high-strength steel

International Journal of Solids and Structures ◽

10.1016/j.ijsolstr.2020.07.010 ◽

2020 ◽

Vol 202 ◽

pp. 672-684

Author(s):

Toshiro Amaishi ◽

Hideo Tsutamori ◽

Takeshi Nishiwaki ◽

Takaaki Kimoto

Keyword(s):

Sheet Metal ◽

High Strength Steel ◽

High Strength ◽

Hole Expansion ◽

Anisotropic Properties ◽

Expansion Test ◽

Hole Expansion Test ◽

Spline Curves

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Increasing the Hole Expansion Ability of High Strength Steel Sheet by Improving the Pre-Hole Shearing Process

Materials Science Forum ◽

10.4028/www.scientific.net/msf.962.167 ◽

2019 ◽

Vol 962 ◽

pp. 167-174

Author(s):

Prasan Saengkhiao ◽

Komgrit Lawanwong ◽

Pakorn Chumrum

Keyword(s):

High Strength Steel ◽

Steel Sheet ◽

High Strength ◽

Expansion Ratio ◽

Expansion Process ◽

Forming Process ◽

Research Papers ◽

Hole Expansion ◽

Hole Edge ◽

Hole Expansion Ratio

The hole expansion process is a forming process that the fracture easily occurred on the hole edge. Therefore, many research papers presented various processes to make a precision pre-hole shearing to a hole expansion process such as wire cut, EDM, and laser cut. The purpose of this work is to increase a hole expansion ratio on the high strength steel sheet. The conventional piercing by piercing punch and piercing with a counter punch was used to make a pre-hole shearing process in this research paper. The high strength steel grade 590 and 980 MPa of 1.2 mm of thickness were used in the experiments. From experimental results, it was found that the pre-hole shearing by piercing with a counter punch can be increased a shear surface on cutting edge of workpiece. Moreover, the used piercing with counter punch can improve the hole expansion ratio more than the conventional piercing process because sheared surface around the hole edge was increased.

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Anisotropic Plastic Behavior of TRIP 780 Steel Sheet in Hole Expansion Test

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.504-506.89 ◽

2012 ◽

Vol 504-506 ◽

pp. 89-94 ◽

Cited By ~ 6

Author(s):

Sansot Panich ◽

Vitoon Uthaisangsuk ◽

Surasak Suranuntchai ◽

Suwat Jirathearanat

Keyword(s):

Steel Sheet ◽

Flow Behavior ◽

Plastic Anisotropy ◽

Yield Potential ◽

Uniaxial Tensile ◽

Plastic Behavior ◽

Biaxial Test ◽

Hole Expansion ◽

Expansion Test ◽

Hole Expansion Test

Plastic behavior of advanced high strength steel sheet of grade TRIP780 (Transformation Induced Plasticity) was investigated using three different yield functions, namely, the von Mises’s isotropic, Hill’s anisotropic (Hill’48), and Barlat’s anisotropic (Yld2000-2d) criterion. Uniaxial tensile and balanced biaxial test were conducted for the examined steel in order to characterize flow behavior and plastic anisotropy in different stress states. Additionally, disk compression test was performed for obtaining the balanced r-value. According to the different yield criteria, yield stresses and r-values were calculated for different directions and then compared with experimental data. To verify the modeling accuracy, a hole expansion test was carried out experimentally and numerically by FE simulation. Stress-strain curve from the biaxial test was described using voce and swift hardening models. Punch load and stroke, final hole radius, and strain distribution on specimen surface along the hole circumference and the specimen diameter in rolling and transverse directions were determined and compared with the experimental results. It was found that the simulations applying Yld2000-2d yield function provided an acceptable agreement. Consequently, it is noted that the anisotropic yield potential significantly affects the accuracy of the predicted deformation behavior of sheet metal subjected to hole expanding load.

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