Characterizing and Modeling Brittle Bi-material Interfaces Subjected to Shear

Konstantinos Anyfantis, Christian Berggreen

Research output: Contribution to journalJournal articleResearchpeer-review

Abstract

This work is based on the investigation, both experimentally and numerically, of the Mode II fracture process and bond strength of bondlines formed in co-cured composite/metal joints. To this end, GFRP-to-steel double strap joints were tested in tension, so that the bimaterial interface was subjected to shear with debonding occurring under Mode II conditions. The study of the debonding process and thus failure of the joints was based both on stress and energy considerations. Analytical formulas were utilized for the derivation of the respective shear strength and fracture toughness measures which characterize the bi-material interface, by considering the joint’s failure load, geometry and involved materials. The derived stress and toughness magnitudes were further utilized as the parameters of an extrinsic cohesive law, applied in connection with the modeling the bi-material interface in a finite element simulation environment. It was concluded that interfacial fracture in the considered joints was driven by the fracture toughness and not by strength considerations, and that LEFM is well suited to analyze the failure of the joint. Additionally, the double strap joint geometry was identified and utilized as a characterization test for measuring the Mode II fracture toughness of brittle bimaterial interfaces.
Original languageEnglish
JournalApplied Composite Materials
Volume21
Pages (from-to)905–919
ISSN0929-189X
DOIs
Publication statusPublished - 2014

Keywords

  • Fracture characterization
  • Cohesive law
  • Interfacial debonding
  • Composite-to-metal
  • Bi-material interface
  • LEFM

Cite this

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title = "Characterizing and Modeling Brittle Bi-material Interfaces Subjected to Shear",
abstract = "This work is based on the investigation, both experimentally and numerically, of the Mode II fracture process and bond strength of bondlines formed in co-cured composite/metal joints. To this end, GFRP-to-steel double strap joints were tested in tension, so that the bimaterial interface was subjected to shear with debonding occurring under Mode II conditions. The study of the debonding process and thus failure of the joints was based both on stress and energy considerations. Analytical formulas were utilized for the derivation of the respective shear strength and fracture toughness measures which characterize the bi-material interface, by considering the joint’s failure load, geometry and involved materials. The derived stress and toughness magnitudes were further utilized as the parameters of an extrinsic cohesive law, applied in connection with the modeling the bi-material interface in a finite element simulation environment. It was concluded that interfacial fracture in the considered joints was driven by the fracture toughness and not by strength considerations, and that LEFM is well suited to analyze the failure of the joint. Additionally, the double strap joint geometry was identified and utilized as a characterization test for measuring the Mode II fracture toughness of brittle bimaterial interfaces.",
keywords = "Fracture characterization, Cohesive law, Interfacial debonding, Composite-to-metal, Bi-material interface, LEFM",
author = "Konstantinos Anyfantis and Christian Berggreen",
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language = "English",
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pages = "905–919",
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}

Characterizing and Modeling Brittle Bi-material Interfaces Subjected to Shear. / Anyfantis, Konstantinos; Berggreen, Christian.

In: Applied Composite Materials, Vol. 21, 2014, p. 905–919.

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Characterizing and Modeling Brittle Bi-material Interfaces Subjected to Shear

AU - Anyfantis, Konstantinos

AU - Berggreen, Christian

PY - 2014

Y1 - 2014

N2 - This work is based on the investigation, both experimentally and numerically, of the Mode II fracture process and bond strength of bondlines formed in co-cured composite/metal joints. To this end, GFRP-to-steel double strap joints were tested in tension, so that the bimaterial interface was subjected to shear with debonding occurring under Mode II conditions. The study of the debonding process and thus failure of the joints was based both on stress and energy considerations. Analytical formulas were utilized for the derivation of the respective shear strength and fracture toughness measures which characterize the bi-material interface, by considering the joint’s failure load, geometry and involved materials. The derived stress and toughness magnitudes were further utilized as the parameters of an extrinsic cohesive law, applied in connection with the modeling the bi-material interface in a finite element simulation environment. It was concluded that interfacial fracture in the considered joints was driven by the fracture toughness and not by strength considerations, and that LEFM is well suited to analyze the failure of the joint. Additionally, the double strap joint geometry was identified and utilized as a characterization test for measuring the Mode II fracture toughness of brittle bimaterial interfaces.

AB - This work is based on the investigation, both experimentally and numerically, of the Mode II fracture process and bond strength of bondlines formed in co-cured composite/metal joints. To this end, GFRP-to-steel double strap joints were tested in tension, so that the bimaterial interface was subjected to shear with debonding occurring under Mode II conditions. The study of the debonding process and thus failure of the joints was based both on stress and energy considerations. Analytical formulas were utilized for the derivation of the respective shear strength and fracture toughness measures which characterize the bi-material interface, by considering the joint’s failure load, geometry and involved materials. The derived stress and toughness magnitudes were further utilized as the parameters of an extrinsic cohesive law, applied in connection with the modeling the bi-material interface in a finite element simulation environment. It was concluded that interfacial fracture in the considered joints was driven by the fracture toughness and not by strength considerations, and that LEFM is well suited to analyze the failure of the joint. Additionally, the double strap joint geometry was identified and utilized as a characterization test for measuring the Mode II fracture toughness of brittle bimaterial interfaces.

KW - Fracture characterization

KW - Cohesive law

KW - Interfacial debonding

KW - Composite-to-metal

KW - Bi-material interface

KW - LEFM

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