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

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

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

2016 ◽  
Vol 725 ◽  
pp. 592-597 ◽  
Author(s):  
Toshiya Suzuki ◽  
Kazuo Okamura ◽  
Yuya Ishimaru ◽  
Hiroshi Hamasaki ◽  
Fusahito Yoshida
Keyword(s):  
High Strength Steel ◽  
Deformation Behavior ◽  
Steel Sheet ◽  
High Strength ◽  
Localized Deformation ◽  
Hole Expansion ◽  
Expansion Test ◽  
Hole Edge ◽  
Hole Expansion Test ◽  
Hot Rolled

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.

Fundamental aspect of stretch-flangeability of sheet metals

2018 ◽  
Vol 233 (10) ◽  
pp. 2115-2119 ◽  
Author(s):  
Surajit Kumar Paul
Keyword(s):  
Tensile Test ◽  
Sheet Metal ◽  
Expansion Ratio ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Hole Expansion ◽  
Expansion Test ◽  
Localized Necking ◽  
Hole Expansion Test ◽  
Hole Expansion Ratio

Stretch-flangeability of sheet metal is normally represented by hole expansion ratio. Hole expansion ratio cannot be determined from uniaxial tensile test though uniaxial tensile deformation occurs at the hole’s edge, because of fundamental difference in deformation and damage processes present between hole expansion test and uniaxial tensile test. It is proposed that only localized necking is observed in hole expansion test; however, diffuse necking followed by localized necking is observed in uniaxial tensile test of sheet metal. It is noticed that the hole expansion ratio is marginally higher than maximum diffuse neck strain determined from uniaxial tensile test with local strain measurement by digital image correlation technique. The absence of diffuse neck in hole expansion test with defect-free central hole (i.e. electrical discharge machined hole) results far higher hole expansion ratio than uniform elongation of the material.

Fracture characteristics of advanced high strength steels during hole expansion test

2020 ◽  
Vol 224 (2) ◽  
pp. 217-233 ◽  
Author(s):  
Vivek Kumar Barnwal ◽  
Shin-Yeong Lee ◽  
Seong-Yong Yoon ◽  
Jin-Hwan Kim ◽  
Frédéric Barlat
Keyword(s):  
High Strength Steels ◽  
High Strength ◽  
Fracture Characteristics ◽  
Hole Expansion ◽  
Expansion Test ◽  
Advanced High Strength Steels ◽  
Hole Expansion Test

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

2012 ◽  
Vol 504-506 ◽  
pp. 89-94 ◽  
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.

Image Processing Algorithm for Real-Time Crack Inspection in Hole Expansion Test

2019 ◽  
Vol 20 (7) ◽  
pp. 1139-1148 ◽  
Author(s):  
Seungho Choi ◽  
Kwangyoon Kim ◽  
Jaeho Lee ◽  
Sung Hyuk Park ◽  
Hye-Jin Lee ◽  
...  
Keyword(s):  
Image Processing ◽  
Real Time ◽  
Processing Algorithm ◽  
Image Processing Algorithm ◽  
Hole Expansion ◽  
Expansion Test ◽  
Hole Expansion Test

Investigation on Forming Behaviour of Sheet Metal by Test Using Cylindrical Cup with Hole

2018 ◽  
Vol 789 ◽  
pp. 51-58
Author(s):  
Bhadpiroon Watcharasresomroeng
Keyword(s):  
Sheet Metal ◽  
High Strength Steel ◽  
High Strength ◽  
Materials Testing ◽  
Drawing Ratio ◽  
Blank Holder ◽  
Steel Sheets ◽  
Fuel Consumption Rate ◽  
Materials Used ◽  
Cylindrical Cup

Nowadays, there are several grades of sheet metal used in the automotive industry. Highstrength steel sheets, particularly, have been widely used in order to reduce the weight of vehicles,which is strongly related to their fuel consumption rate. However, it is generally known that thestrength of the sheets, which is relatively higher than that of the conventional carbon steel sheets,results in their low formability. In this work, the limiting drawing ratio and forming behavior of sheetmetal that is conventionally used for automobile parts were evaluated by test using cylindrical cupwith hole. The feasibility to use limiting cup height for comparing formability of sheet metal was alsoincluded in the investigation. The sheet materials used in the experiments are aluminium, cold rolledsteel, high strength steel and advanced high strength steel. The process parameters for this study weredie corner radius and blank holder force. Workpiece materials were prepared with a circular shapeand with a diameter of 80 millimetres. In the center of the circular workpiece, a 12-millimetrediameter hole was drilled to observe the formability of each of the materials. The advantage of usingan initial blank with a hole in the center by the cylindrical cup drawing test is that the cup does notfail from changes of the thickness of material near the punch radius at the bottom of the cup. Thelimiting cup height of the investigated materials were evaluated by test using the cylindrical cup withhole. The results show that the limiting cup height values have a relationship to the limiting drawingratio values of the investigated materials. Testing using cylindrical cup with hole by evaluating thelimiting cup height value is feasible for comparing the formability of sheet metals.

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