Numerical Modelling and Analysis of Ductile Crack Propagation in Blanking Process Using Modified Nodal Release Method


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Ductile fracture processes for discrete crack propagation using nodal release approach is well established for modelling crack in metal sheet. In this method, the crack is assumed to initiate or propagate along the element edges; hence, a new crack is implemented in the FE mesh. In Blanking process, the crack trajectory is unknown; therefore a very fine mesh is required to simulate a realistic crack propagation using the nodal release method. Consequently, the nodal release method has to be modified in which first the direction of crack extension is calculated and then, accordingly, the local element topology near the crack-tip is modified such that the nodes of elements are moved to predicted crack-tip in order to accommodate the crack extension. The advantage of this method is that it is possible to model the predicted crack with only slight modification in the local mesh near to the crack tip. However, it is necessary to transfer history variables from old local elements of previous increment to the new local elements of the current increment at the vicinity of crack-tip. But this method can lead to slight loss of accuracy to predict the subsequent crack extension due to interpolations. However, the advantage of this method is that remeshing can be either completely eliminated or reduced to a greater extend during the simulation. Therefore, in this paper, modified nodal release method for modelling ductile crack propagation in blanking process with the uncoupled damage approach is presented, and is further implemented in commercial FE software - MSC.Marc® together with predefined user-subroutines



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Edited by:

F. Micari, M. Geiger, J. Duflou, B. Shirvani, R. Clarke, R. Di Lorenzo and L. Fratini




B. A. Behrens and K. B. Sidhu, "Numerical Modelling and Analysis of Ductile Crack Propagation in Blanking Process Using Modified Nodal Release Method", Key Engineering Materials, Vol. 344, pp. 201-208, 2007

Online since:

July 2007




[1] W. Johnson, R. A. C. Slater: Survey of slow and fast blanking of metals at ambient and high temperatures. Proc. of Int. Manufacturing Tech., CIRP-ASTME (1967), pp.822-851.

[2] M Choy, R. Balendra: Experimental analysis of parameters influencing the sheared-edge profiles, In Proc. of 4th Int. Confer. on Sheet Metal, Twente (1996), pp.101-110.

[3] H. -H. Schmuetsch: Einflussgroessen auf das Schneidergebnis beim Scherschneiden von Feinblechen, Ph. D thesis, IFUM, University of Hanover, (1990).

[4] T. M. Chang: Shearing of metal blanks, J. of Inst. of Metals, 78 (1951), pp.393-414.

[5] M Samuel: FEM simulations and experimental analysis of parameters of influence in the blanking process, J. of Mat. Process. Tech. Vol. 84 Dec. (1998), pp.97-106.

[6] Taupin, J. Breitling, W-T. Wu, T. Altan: Materials fracture and burr formation in blanking results of FEM simulations and comparison with experiments, J. of Mat. Process. Tech., 59 (1996), pp.68-78.

DOI: 10.1016/0924-0136(96)02288-1

[7] A.M. Goijaerts, Y.W. Stegeman, L. E. Govaert, D. Brokken, W. A. M. Brekelmans, F. P. T. Baaijens: Can a new experimental and numerical study improve metal blanking?, Proc. of the Int. Sheet Metal Confer., Vol. 1, Twente (1998), p- 185-194.

DOI: 10.1016/s0924-0136(00)00417-9

[8] D. Brokken, W. A. M. Brekelmans, F. P. T. Baaijens: Predicting the shape of blanked products: a Finite Element approach, Proc. of the Int. Sheet Metal Confer., Vol. 1, Twente (1998), p- 195-204.

DOI: 10.1016/s0924-0136(00)00418-0

[9] Fang, G.; Zeng, P.; Lou, L.: Finite element simulation of the effect of clearance on the forming quality in the blanking process, Journal of material processing Technology, 122 (2002), p.249254.

[10] B. Dood; Y. Bai: Ductile fracture and ductility - with applications to metalworking. (Academic press, London, 1987).

[11] P. F. Thomason: Ductile Fracture of Metals. (Pergamon press, 1990).

[12] Gurson: Continuum theory of ductile rapture by void nucleation and growth: Part I - Yield criteria and flow rules of porous ductile media. J. of Engg. Mat. Vol. 99 (1977), pp.2-15.

DOI: 10.2172/7351470

[13] J. Lemaitre: A continuum damage mechanics model for ductile fracture, J. Engg. Mat. Tech. Vol. 107 (1985), pp.83-89.

[14] V. Tvergaard: Material failure by void growth to coalescence. Adv. in App. Mechanics. Vol. 27 (1990), pp.83-151.

[15] F. A. McClintock: A criterion for ductile fracture by growth of holes subjected to multi-axial stress-states. J. of App. Mechanics. Vol. 35 (1968), pp.33-39.

[16] J. R. Rice, D. M. Tracey: On the ductile enlargement of voids in triaxial stress fields. J. of Mechanics and Phy. of Solids. Vol. 17 (1969), pp.201-217.

DOI: 10.1016/0022-5096(69)90033-7

[17] M. Oyane, T. Sato, K. Okimoto, S. Shima: Criteria for ductile fracture and their application, J. of Mech. Work. Tech. Vol. 4 (1980).

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