Modelling Local Brittle Zones in Welds Using the Finite Element Method


Article Preview

This paper reports the results of a numerical study concerning the influence of local brittle zones intersecting the crack front on the fracture behaviour of welded joints. This work was performed using the numerical simulation of the three point bending test of weld samples with different amount of brittle structures at the crack front. Using 3D finite element discretization it was possible to simulate welded samples with very small fractions of brittle zone at the crack front, such as 5 %. Comparing the results of samples with increasing proportion of brittle zone it was observed a significant decrease in the crack growth resistance with increasing amounts of brittle material. This decrease in crack growth resistance was obtained even for samples with very small amounts of brittle material at the crack front.



Materials Science Forum (Volumes 514-516)

Edited by:

Paula Maria Vilarinho




P. Teixeira et al., "Modelling Local Brittle Zones in Welds Using the Finite Element Method", Materials Science Forum, Vols. 514-516, pp. 1419-1423, 2006

Online since:

May 2006




[1] A. J. R. Loureiro, A. A. Fernandes: Toughness of CG HAZs of Welds in Q&T Steels, Welding Journal 73 (9) (1994), p. 225s-235s.

[2] J. Jang, B. Lee, J. Ju, D. Kwon, W. Kim: Experimental analysis of the practical LBZ effects on the brittle fracture performance of cryogenic steel HAZs with respect to crack arrest toughness near fusion line, Engineering Fracture Mechanics 70 (2003).


[3] J. Neves, A. Loureiro: Fracture toughness of welds - effect of brittle zones and strength mismatch, Journal of Materials Processing Technology 153-154 (2004), pp.537-543.


[4] J. Jang, J. Lee, J. Ju, B. Lee, D. Kwon, W. Kim: Determination of microstructural criterion for cryogenic toughness variation in actual HAZs using microstructure-distribution maps, Materials Science and Engineering A351 (2003), pp.183-189.


[5] L. F. Menezes, C. Teodosiu: Three-dimensional numerical simulation of the deep-drawing process using solid finite elements, Journal of Materials Processing Technology 97 (2000), p.100106.


[6] P. Teixeira, A. Loureiro, D. M. Rodrigues, J. Neves: Effect of the HAZ microstructural gradient on the unstable fracture of welds in high strength steel. Accepted to Materials Science Forum.


[7] J. W. Hutchinson: Fundamentals of the phenomenological theory of nonlinear fracture mechanics. ASME J. Appl. Mech. 50 (1983), pp.1042-1051.


[8] O.M. Akselsen, G. R∅rvik, M.I. Ons∅ien, ∅. Grong: Assessment and predictions of HAZ tensile properties of high-strength steels. Welding Journal, 69(9) (1989): 356s-362s.

[9] J.R. Rice: A path independent integral and the approximate analysis of strain concentration by notches and cracks. ASME J. Appl. Mech., 35 (1968): 379-386.