Tecnologia em Metalurgia, Materiais e Mineração
Tecnologia em Metalurgia, Materiais e Mineração
Artigo Original - Edição Especial “Tributo ao Prof. T. R. Strohaecker”

Comparative study between crack tip opening displacement techniques by statistical analysis

Matheus Lothar Schmidt, Guilherme Vieira Braga Lemos, Daniel Antonio Kapper Fabricio, Afonso Reguly

Downloads: 0
Views: 427


Standardized tests may not always achieve all their analytical objectives. Particularly to structural integrity, where a reproduction of the practical occurrences of the industry is desired, new techniques are being developed. Therefore, this work aims at evaluating fracture toughness in tensile armour through four measurement methodologies (standard, video, laser and stretch zone (SZ)) to obtain crack tip opening displacement (CTOD), and compares their responses by ANOVA and Duncan’s tests. The findings showed equivalence between the standard and other approaches, thus allowing distinct methods for fracture toughness evaluation.


Fracture toughness; Crack tip opening displacement; Tensile armour wire; Statistical analysis


1 Schwalbe KH. Introduction of delta-5 as an operational definition of the CTOD and its practical use. Fracture Mechanics. 1995;26:763-778.

2 Castrodeza E, Touça JMR, Perez Ipiña JE, Bastian FL. Determination of CTODC in fibre metal laminates by ASTM and Schwalbe methods. Materials Research. 2002;5(2):119-124. http://dx.doi.org/10.1590/S1516-14392002000200006.

3 Suresh RKV, Ramakrishnan N, Srinivas M, Ramarao PJ. On the determination of JIC using the stretch zone width method. Journal of Testing and Evaluation. 1999;27(3):211-218.

4 Ernst HA. Relations between the crack tip opening displacement, δ5 , and the modified J, JM. Geesthacht: The Crack Tip Opening Displacement in Elastic-Plastic Fracture Mechanics. p. 197-206, 1985.

5 Castrodeza EM, Perez Ipiña JE, Bastian FL. Fracture toughness evaluation of unidirectional fibre metal laminates using traditional CTOD (δ) and Schwalbe (δ5) methodologies. Engineering Fracture Mechanics. 2004;71(7-8):1127-1138.

6 Sivaprasad S, Tarafder S. Ranganath VR, Das, Sk, Ray KK. Can stretch zone measurements provide a good estimate of fracture toughness? In Proceedings of the 10th International Congress of Fracture (ICF10); 2001; Honolulu, Hawaii. Honolulu: ICF; 2001.

7 Saxena S, Ramakrishnan N, Dutta BK. Determination of stretch zone width using fem. Engineering Fracture Mechanics. 2009;76(7):911-920. http://dx.doi.org/10.1016/j.engfracmech.2008.12.015.

8 Schwalbe KH, Heerens J, Hellmann D, Cornec A. Relationships between various definitions of the crack tip opening displacement. Geesthacht: The Crack Tip Opening Displacement in Elastic-Plastic Fracture Mechanics; 1985. p. 133-153.

9 ASTM International. ASTM E1820: standard test method for measurement of fracture toughness. West Conshohocken: ASTM; 2017.

10 Tagliari MR, Antunes MR, Santos JGN, Santos FP, Santos JMC, Falcade T, et al. Tensile armor wires submitted to slow strain rate tests in a corrosive environment and cathodic protection: a comparison between two different microstructures. Materials Research. 2019;22(3):e20180465. http://dx.doi.org/10.1590/1980-5373-mr-2018-0465.

11 ASTM International. ASTM E8/E8M: tension testing of metallic materials. West Conshohocken: ASTM; 2015.

12 Hellman D, Schwalbe KH. Fracture Mechanics: Fifteenth Symposium. ASTM Special Technical Publication. 1984;833:577-603.

13 Farias AML, Demarqui FN. Análise de variância. 1. ed. Rio de Janeiro: UFF; 2017.

14 Duncan DB. Multiple range and multiple F tests. Biometrics. 1955;11(1):1-42.

15 Potter JM. Fatigue and fracture testing of weldments. Vol. 1058. West Conshohocken: ASTM International; 1990.

16 Chiodo SG. Procedimento de avaliação da integral J e CTOD para dutos com trincas circunferenciais submetidos à flexão e aplicações à Instalação de risers pelo método carretel [dissertação]. São Paulo: USP; 2009.

17 Anderson TL. Fracture mechanics: fundamentals and applications. 3rd ed. Boca Raton: Taylor & Francis; 2004.

18 Tendela LP, Galizzi GE. Interferometric displacement measurement on scattering surfaces utilizing speckle effect Interferometric displacement measurement on scattering surfaces utilizing speckle effect. Journal of Physics. E, Scientific Instruments. 1970;3:214-218.

19 Ohtsuka Y, Itoh K. Two-frequency laser interferometer for small displacement measurements in a low frequency range. Applied Optics. 1979;18(2):219-224. http://dx.doi.org/10.1364/AO.18.000219.

20 Liu P, Zhang G, Zhai T, Feng K. Effect of treatment in weld surface on fatigue and fracture behavior of titanium alloys welded joints by vacuum electron beam welding. Vacuum. 2017;141:176-180. http://dx.doi.org/10.1016/j.vacuum.2017.04.019.

21 Chowdhury T, Sivaprasad S, Bar HN, Tarafder S, Bandyopadhyay NR. Stretch zone formation in cyclic fracture of 20MnMoNi55 pressure vessel steel. Engineering Fracture Mechanics. 2015;148:60-72. http://dx.doi.org/10.1016/j.engfracmech.2015.09.026.

22 Souza AM, Ethur ABM, Lopes LFD, Zanini RR. Introdução a projetos de experimentos. 1. ed. Santa Maria: UFSM; 2002.

Submetido em:

Aceito em:

604f5129a953954a49152a55 tmm Articles
Links & Downloads

Tecnol. Metal. Mater. Min.

Share this page
Page Sections