Research Papers

Edge Fracture Prediction of Traditional and Advanced Trimming Processes for AA6111-T4 Sheets

[+] Author and Article Information
X. H. Hu

Computational Science
and Mathematics Division,
Pacific Northwest National Laboratory,
Richland, WA 99354
e-mail: Xiaohua.hu@pnnl.gov

K. S. Choi, X. Sun

Computational Science
and Mathematics Division,
Pacific Northwest National Laboratory,
Richland, WA 99354

S. F. Golovashchenko

Manulfacturing and Processes Department,
Ford Research and Advanced Engineering,
Scientific Research Laboratory,
Dearborn, MI 48124

1Corresponding author.

Manuscript received March 25, 2013; final manuscript received November 15, 2013; published online February 12, 2014. Assoc. Editor: Brad L. Kinsey.

J. Manuf. Sci. Eng 136(2), 021016 (Feb 12, 2014) (11 pages) Paper No: MANU-13-1104; doi: 10.1115/1.4026273 History: Received March 25, 2013; Revised November 15, 2013

This work examines the traditional and advanced trimming of AA6111-T4 aluminum sheets with finite element simulations. The Rice-Tracy damage model is used for the simulation with damage parameters estimated from experimental observation of grain aspect ratio near the fracture surface of trimmed parts. Fine meshes at the shearing zone, adaptive meshing, and adaptive contact techniques are used to accurately capture the contact interactions between the sharp corner of the trimming tools and the blank to be trimmed. To the knowledge of the authors, these are the first trimming simulations that can predict the effects of shearing clearance on burr heights with quantitative accuracy for AA6111-T4 aluminum sheets. In addition, the models have also accurately reproduced the crack initiation site as well as burr and sliver formation mechanisms observed experimentally.

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Golovashchenko, S. F., 2006, “A Study on Trimming of Aluminum Autobody Sheet and Development of a New Robust Process Eliminating Burrs and Slivers,” Int. J. Mech. Sci., 48, p. 1384. [CrossRef]
Golovashchenko, S. F., 2008, “Quality of Trimming and Its Effect on Stretch Flanging of Automotive Panels,” J. Mater. Eng. Perform., 17, p. 316. [CrossRef]
Golovashchenko, S. F.,1999, “Numerical and Experimental Analysis of the Tirmming Process,” presented at NUMISHEET'99, 13 Sept.
Golovashchenko, S. F., 1999, “A Study on Trimming of Al Alloys Parts,” presented at Advanced Technology of Plasticity 1999, Nuremburg, 19 Sept.
Golovashchenko, S. F., 2007, "Analysis of Trimming of Aluminum Closure Panels," J. Mater. Eng. Perform., 16, p. 213. [CrossRef]
Li, M., 2000, “Micromechanisms of Deformation and Fracture in Shearing Aluminum Alloy Sheet,” Int. J. Mech. Sci., 42, p. 889. [CrossRef]
Ilinich, A. M., Golovashchenko, S. F., and Smith, L. M., 2011, “Material Anisotropy and Trimming Method Effects on Total Elongation in DP500 Sheet Steel,” J. Mater. Process. Technol., 211, p. 441. [CrossRef]
Smith, D. A., 1999, Die Design Handbook, Society of Manufacturing Engineers, Dearborn, MI.
Gillespie, L. K., 1999, Deburring and Edgefinishing Handbook, Society of Manufacturing Engineers, Dearborn, MI.
Chen, Z. H., Tang, C. Y., Lee, T. C., and Chan, L. C., 2002, “Numerical Simulation of Fine-Blanking Process Using a Mixed Finite Element Method,” Int. J. Mech. Sci., 44, p.1309. [CrossRef]
Chang, T. M., and Swift, H. W., 1950, “Shearing of Metal Bars,” J. Inst. Met., 78, p. 393.
Atkins, A. G., 2003, “Modelling Metal Cutting Using Modern Ductile Fracture Mechanics: Quantitative Explanations for Some Longstanding Problems,” Int. J. Mech. Sci., 45, p. 373. [CrossRef]
Atkins, A. G., 1981, “Surfaces Produced by Guillotining,” Philos. Mag. A, 43, p. 627. [CrossRef]
Taupin, E., Breitling, J., Wu, W. t., and Altan, T., 1996, “Material Fracture and Burr Formation in Blanking Results of FEM Simulations and Comparison With Experiments,” J. Mater. Process. Technol., 59, p. 68. [CrossRef]
Hambli, R., and Reszka, M., “Fracture Criteria Identification Using an Inverse Technique Method and Blanking Experiment,” 2002, Int. J. Mech. Sci., 44, p. 1349. [CrossRef]
Hilditch, T. B., and Hodgson, P. D., 2005, “Development of the Sheared Edge in the Trimming of Steel and Light Metal Sheet: Part 2: Mechanisms and Modeling,” J. Mater. Process. Technol., 169, p. 192. [CrossRef]
Gutscher, G., Wu, H. C., Ngaile, G., and Altan, T., 2004, “Determination of Flow Stress for Sheet Metal Forming Using the Viscous Pressure Bulge (VPB) Test,” J. Mater. Process. Technol., 146, p. 1. [CrossRef]
Nasser, A., Yadav, A., Pathak, P., and Altan, T., 2010, “Determination of the Flow Stress of Five AHSS Sheet Materials (DP 600, DP 780, DP 780-CR, DP 780-HY and TRIP 780) Using the Uniaxial Tensile and the Biaxial Viscous Pressure Bulge (VPB) Tests,” J. Mater. Process. Technol., 210, p. 429. [CrossRef]
Jain, M., Lloyd, D. J., and MacEwen, S. R., 1996, “Hardening Laws, Surface Roughness and Biaxial Tensile Limit Strains of Sheet Aluminium Alloys,” Int. J. Mech. Sci., 38, p. 219. [CrossRef]
Kang, J. D., Wilkinson, D. S., Wu, P. D., Bruhis, M., Jain, M., Embury, J. D., and Mishra, R. K., 2008, “Constitutive Behavior of AA5754 Sheet Materials at Large Strains,” ASME J. Eng. Mater. Technol., 130, p. 031004. [CrossRef]
Scheider, I., Brocks, W., and Cornec, A., 2004, “Procedure for the Determination of True Stress-Strain Curves from Tensile Tests With Rectangular Cross-Section Specimens,” ASME J. Eng. Mater. Technol., 126, P. 70. [CrossRef]
Smith, L. M., Wanintrudal, C., Yang, W., and Jiang, S., 2009, “A New Experimental Approach for Obtaining Diffuse-Strain Flow Stress Curves,” J. Mater. Process. Technol., 209, p. 3830. [CrossRef]
Zhang, Z. L., Hauge, M., Odegard, J., and Thaulow, C., 1999, “Determining Material True Stress-Strain Curve From Tensile Specimens With Rectangular Cross-Section,” Int. J. Solids Struct., 36, p. 3497. [CrossRef]
Bridgeman, P. W., 1952, Studies in Large Plastic Flow and Fracture, McGraw-Hill, New York.
Mcclintock, F. A., 1968, “Criterion for Ductile Fracture by Growth of Holes,” ASME J. Appl. Mech., 35, p. 363. [CrossRef]
Rice, J. R., and Tracey, D. M., 1969, “On the Ductile Enlargement of Voids in Triaxial Stress Fields,” J. Mech. Phys. Solids, 17, p. 201. [CrossRef]
Oyane, M., Sato, T., Okimoto, K., and Shima, S., 1980, “Criteria for Ductile Fracture and Their Applications,” J. Mech. Work. Technol., 4, p. 65. [CrossRef]
Johnson, G. R., and Cook, W. H., 1985, “Fracture Characteristics of Three Metals Subjected to Various Strains, Strain Rates, Temperatures and Pressures,” Eng. Fract. Mech., 21, p. 31. [CrossRef]
Huber, M. T., 1904, “Contribution to the Foundation of the Strength of the Material,” Czas. Tech., 22, p. 81.
Hu, X. H., Wilkinson, D. S., Jain, M., and Mishra, R. K., 2010, “A parametric finite element study and an analytical model of particle distributions on post-necking deformation and failure mode in AA5754 aluminum alloy sheets” Int. J. Fract., 164, p. 167. [CrossRef]
Hu, X. H., Wilkinson, D. S., Jain, M., Wu, P. D., and Mishra, R. K., 2011, “The Impact of Particle Distributions and Grain-Level Inhomogeneities on Post-Necking Deformation and Fracture in AA5754 Sheet Alloys During Uniaxial Tension,” Mater. Sci. Eng., A,528, p. 2002. [CrossRef]
Wilkins, M. L., Streit, R. D., and Reaugh, J. E., 1980, Cumulative-Strain-Damage Model of Ductile Fracture: Simulation and Prediction of Engineering Fracture Tests, Lawrence Livermore Laboratory, Livermore, CA, Vol. 1.
Hooputra, H., Gese, H., Dell, H., and Werner, H., 2004, “A Comprehensive Failure Model for Crashworthiness Simulation of Aluminium Extrusions,” Int. J. Crashworthiness, 9, p. 449. [CrossRef]
Xue, L., 2005, “Damage Accumulation and Fracture Initiation in Uncracked Ductile Solids Under Triaxial Loading—Part I: Pressure Sensitivity and Lode Dependence, Impact and Crashworthiness,” Impact and Crashworthiness Laboratory, Massachusetts Institute of Technology, Cambridge, MA, Lab Report No. 138.
Bai, Y., and Wierzbicki, T., 2008, “A New Model of Metal Plasticity and Fracture With Pressure and Lode Dependence,” Int. J. Plast., 24, p. 1071. [CrossRef]
Abaqus, 2011, Abaqus 6.11 User's Manual .
Sun, X., Liu, W. N., Chen, W. N., and Templeton, D., 2009, “Modeling and Characterization of Dynamic Failure of Borosilicate Glass Under Compression/Shear Loading,” Int. J. Impact Eng., 36, p. 226. [CrossRef]
Bardet, J. P., 1990, “Lode Dependences for Isotropic Pressure-Sensitive Elastoplastic Materials,” ASME J. Appl. Mech., 57, p. 498. [CrossRef]
Khan, A. S., and Liu, H., 2012, “A New Approach for Ductile Fracture Prediction on Al 2024-T351 Alloy,” Int. J. Plast., 35, p. 1. [CrossRef]
Gurson, A. L., 1977, “Continuum Theory of Ductile Rupture by Void Nucleation and Growth: Part 1-Yield Criteria and Flow Rules for Porous Ductile Media,” ASME J. Eng. Mater. Technol., 99, p. 2. [CrossRef]
Golovashchenko, S. F., and Blodget, M., 2007, US Patent 7,197,970 B2.
Ludwik, P., 1909, “Element der Technologischen,” Mechanik, p. 32.
MSC, 1997, MSC.Dytran V4 user's Manual.
Hu, X. H., Jain, M., Wilkinson, D. S., and Mishra, R. K., 2008, “Microstructure-Based Finite Element Analysis of Strain Localization Behavior in AA5754 Aluminum Sheet,” Acta Mater., 56, p. 3187. [CrossRef]
Ryen, A., Laukli, H. I., Holmedal, B., and Nes, E., 2006, “Large Strain Work Hardening of Aluminum Alloys and the Effect of Mg in Solid Solution,” Metall. Mater. Trans. A37, p. 2007. [CrossRef]
Saimoto, S., and Van Houtte, P., 2011, “Constitutive Relation Based on Taylor Slip Analysis to Replicate Work-Hardening Evolution,” Acta Mater., 59, p. 602. [CrossRef]
Considere, A. G., 1885, Ann. Ponts Chaussees, 9, p. 574.
Reference Tables—Coefficient of Friction, Engineer's Handbook, http://www.engineershandbook.com/Tables/frictioncoefficients.htm
Javadi, M., and Tajdari, M., 2006, “Experimental Investigation of the Friction Coefficient Between Aluminium and Steel,” Mater. Sci. (Poland), 24, p. 305.
Kaviti, A. K., Prakash, O., and Kumar, P. V., 2011, “Prediction of Coefficient of Friction for Aluminum Billet,” Arch. Appl. Sci. Res., 3, p. 328.


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Fig. 1

Finite element models for the traditional (a) and advanced (b) trimming processes where the middle section of the blank has much finer meshes (c)

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Fig. 2

Examples of a trimmed blank (21% clearance) by the traditional trimming (a)–(c) and the advanced trimming processes (d)–(e)

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Fig. 3

Ludwik fitting of the uniaxial tensile flow curve of AA6111–T4 sheet alloys

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Fig. 4

The micrograph near the fracture surface (a) and the estimated rice-tracey fracture locus (b)

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Fig. 5

Tool-mesh penetration is observed if contacts are inadequately defined between the internal nodes and the tools (a). The penetration is prevented if sufficient contacts are defined (b).

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Fig. 6

The blanked part sides and scrap sides predicted by finite element simulations and the corresponding experimental observations for various clearances

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Fig. 7

The blanked part sides and scrap sides predicted by FE simulations and the corresponding experimental observations for various clearances

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Fig. 8

(a) the normal and tangential (frictional) reaction forces exerted from the deforming sheet on the tools during trimming operations for clearance of 43% (b) the sketch of actual total horizontal and vertical reaction forces on the punch tool for cutting clearances of 10% and 43%, respectively

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Fig. 9

The burr height (b), blank thickness (t), and final cutting clearance (g′), measurements for cutting with 21% clearance.

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Fig. 10

The variation of finite element and experimental relative burr heights (b) for different clearances

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Fig. 11

Stress triaxiality before crack initiation for the simulation with 43% blanking clearance

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Fig. 12

The deformed mesh after crack initiation for the simulation with 43% blanking clearance

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Fig. 13

The deformed mesh after the formation of sliver by the punch roll-over over the tool fillet indent feature for the simulations of the blanking process with 43% clearance

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Fig. 14

The variation of normalized burr height and friction coefficients with friction coefficient for clearance of 43%

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Fig. 15

The variation of equivalent plastis strain with friction coefficient for clearance of 43%

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Fig. 16

The variation of normalized burr with clearances for different friction coefficients



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