Evaluation of structural adhesive joints fracture toughness without crack measurement

The adhesive fracture resistance of structural adhesive joints in mode II, 𝒢_IIC, is accessed through the application of two models that prescind of the measurement of the crack length during the subjection of ENF specimens to three-point bending monotonic tests. The load vs transversal displacement results are used in two different approaches: a damage model and a cohesive zone model. The first one was used in test where the crack propagation was unstable and the second one was used for stable crack propagations. These initial results show the viability of the models and show that both: initial crack length and transversal load rate; have great influence in 𝒢_IIC evaluation.

Keywords
structural adhesive joints; ENF specimens; fracture mechanics

Authorship

Jonnas Santos Alves e-mail:tenjonnas@gmail.com, paulo.kenedi@cefet-rj.br, silvio.debarros@gmail.com

Programa de Pós-Graduação em Engenharia Mecânica e Tecnologia de Materiais (PPEMM) CEFET/RJ, Av. Maracanã, 229, CEP 20271-110, Rio de Janeiro, RJ, BrazilCEFETBrazilRio de Janeiro, RJ, BrazilPrograma de Pós-Graduação em Engenharia Mecânica e Tecnologia de Materiais (PPEMM) CEFET/RJ, Av. Maracanã, 229, CEP 20271-110, Rio de Janeiro, RJ, Brazil

https://orcid.org/0000-0002-6155-0423

Paulo Pedro Kenedi e-mail:tenjonnas@gmail.com, paulo.kenedi@cefet-rj.br, silvio.debarros@gmail.com

https://orcid.org/0000-0001-5563-843X

Silvio de Barros e-mail:tenjonnas@gmail.com, paulo.kenedi@cefet-rj.br, silvio.debarros@gmail.com

https://orcid.org/0000-0002-2520-569X

Corresponding Author: Jonnas Santos Alves

e-mail:tenjonnas@gmail.com, paulo.kenedi@cefet-rj.br, silvio.debarros@gmail.com

SCIMAGO INSTITUTIONS RANKINGS

Figures | Tables | Formulas

Figures (10)
Tables (2)
Formulas (36)

Test	a	C(a)	u(P, 𝒢_IIC)
ENF	0 ≤ a₁ < L	$\frac{L^{3}}{48 E I} + \frac{a_{1}^{3}}{32 E I}$	$u_{1} (P, G_{I I C}) = \frac{P L^{3}}{48 E I} + \frac{16}{P^{2}} \sqrt{E I} {(\frac{B G_{I I C}}{3})}^{3 / 2}$
ENF	L ≤ a₂ ≤ 2L	$\frac{- 3 {(3 L - a_{2})}^{3} + 8 L^{3}}{96 E I}$	$u_{2} (P, G_{I I C}) = \frac{P L^{3}}{12 E I} - \frac{16}{P^{2}} \sqrt{E I} {(\frac{B G_{I I C}}{3})}^{3 / 2}$

force to onset yielding the substrate (P₁) (bending)	force to break (rupture) the adhesive (P₂) (shear)
7137 N	6773 N