NUMERICAL DETERINATION OF CRACK INITIATION MOMENT IN CHARPY SPECIMENS AND SIDE-GROOVED SPECIMENS

Евгений Александрович Кондряков, Александр Вячеславович Панасенко

Abstract


Purpose. The object of the presented work is the finite element analysis of Charpy impact tests in the two-dimensional and three-dimensional formulations.

Design/methodology/approachCharpy specimens impact tests are one of more simple and inexpensive method to determine the mechanical properties of materials. The results of these tests can be used to estimate the strength and durability of large-scale structures. Numerical simulation of Charpy specimens impact test can give more information about the features of  crack initiation and propagation in materials under dynamic loading.

Findings. Numerical modelling of Charpy specimens impact tests was performed using Gurson–Tvergaard–Needleman (GTN) damage material model. Local approach to fracture  allows to obtain crack initiation point data inside the specimen and on an edge side of the specimen. Using variable parameters of GTN model one can simulate crack initiation and propagation under different fracture mechanism. Present work describes an estimation of the crack initiation point under brittle, ductile, quasi-brittle fracture mechanisms using GTN model.

Originality/value. The results of numerical modelling of Charpy specimens impact test can be used to evaluate the strength  and life time of construction elements.


Keywords


Charpy specimen;edge notch specimen;finite element method;Gurson–Tvergaard–Needleman damage material model;crack initiation point; fracture mechanism

References


ASTM E1820-01 Standard Test Method for Measurement of Fracture Toughness. In: Annual Book of ASTM Standards.

Proposed standard methods for instrumented pre-cracked Charpy impact testing of steels and other metallic materials // ESIS Procedure P7-00, Draft 25.4: December 2005.

Schindler H.J. Estimation of the dynamic J-R-curve from a single impact bending test / Schindler H.J. // 11th European Conf. on Fracture, 3-6 September 1996. - Poitiers, France, 1996. - P. 2007-2012.

Chaouadi R. Crack resistance determination from the Charpy impact test / Chaouadi R., Puzzolante J.L. // 16th European Conference of Fracture, 3-7 July 2006. - Alexandroupolis, Greece, 2006. – 13 p.

В. В. Харченко, Є. О. Кондряков, А.В. Панасенко Визначення моменту зародження тріщини в зразках Шарпі при ударному навантаженні // Ж-л «Вісник тернопільського національного технічного університету». - ISSN 1727-7108 ТНТ Університет імені Івана Пулюя. - № 3(71), 2013. - с.16-21.

Gurson A.L. Continuum theorie of ductile rupture by void nucleation and growth: Part I–Yield criteria and flow rules for porous ductile media / Gurson A.L. // J. Eng. Mater. Tech. – 1977. – Vol. 99, №1. – P. 2–15.

Tvergaard V. Analysis of the cup-cone fracture in a round tensile bar / Tvergaard V., Needleman A. // Acta Metall. – 1984. – Vol. 32, №1. – P. 157–169.

Кондряков Е.А. Численное моделирование ударных испытаний образцов шарпи в двухмерной и трехмерной постановке // Вісник НТУУ «КПІ». Серiя машинобудування. - №2(71), 2014. – с. 110-113.


GOST Style Citations


ASTM E1820-01 Standard Test Method for Measurement of Fracture Toughness. In: Annual Book of ASTM Standards.

Proposed standard methods for instrumented pre-cracked Charpy impact testing of steels and other metallic materials // ESIS Procedure P7-00, Draft 25.4: December 2005.

Schindler H.J. Estimation of the dynamic J-R-curve from a single impact bending test / Schindler H.J. // 11th European Conf. on Fracture, 3-6 September 1996. - Poitiers, France, 1996. - P. 2007-2012.

Chaouadi R. Crack resistance determination from the Charpy impact test / Chaouadi R., Puzzolante J.L. // 16th European Conference of Fracture, 3-7 July 2006. - Alexandroupolis, Greece, 2006. – 13 p.

В. В. Харченко, Є. О. Кондряков, А.В. Панасенко Визначення моменту зародження тріщини в зразках Шарпі при ударному навантаженні // Ж-л «Вісник тернопільського національного технічного університету». - ISSN 1727-7108 ТНТ Університет імені Івана Пулюя. - № 3(71), 2013. - с.16-21.

Gurson A.L. Continuum theorie of ductile rupture by void nucleation and growth: Part I–Yield criteria and flow rules for porous ductile media / Gurson A.L. // J. Eng. Mater. Tech. – 1977. – Vol. 99, №1. – P. 2–15.

Tvergaard V. Analysis of the cup-cone fracture in a round tensile bar / Tvergaard V., Needleman A. // Acta Metall. – 1984. – Vol. 32, №1. – P. 157–169.

Кондряков Е.А. Численное моделирование ударных испытаний образцов шарпи в двухмерной и трехмерной постановке // Вісник НТУУ «КПІ». Серiя машинобудування. - №2(71), 2014. – с. 110-113.




DOI: http://dx.doi.org/10.20535/2305-9001.2015.73.38313

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