PSI - Issue 25

Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000 il l li t . i i t. t t l t it i

www.elsevier.com/locate/procedia . l i . /l t / i

ScienceDirect

Procedia Structural Integrity 25 (2020) 63–70

© 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the VCSI1 organizers To increase the confidence in the design of adhesive structures, it is important to be able to accurately predict their strength and fracture properties (e.g., critical strain energy release rate in tension, J IC , and shear, J IIC ). Since in most cases the applied loads induce mixed-mode crack growth, it is highly relevant the perception of fracture under these conditions. This work presents an experimental study using the Single-Leg Bending (SLB) test on specimens bonded with Araldite ® 2015, to study and compare the mixed-mode fracture properties. For this purpose, the J -integral method was applied to estimate the tensile ( J I ) and shear fracture energy ( J II ). Framing the obtained values in the fracture envelope enabled to select which power-law failure criterion is more appropriate for the Araldite® 2015. Moreover, the tensile and shear cohesive zone model (CZM) laws were obtained for the adhesive by the direct method. Overall, a very good agreement on the fracture properties was obtained between specimens. The CZM laws also showed a good correspondence between specimens, resulting in a novel methodology for integrated mixed-mode material characterization of structural adhesives for possible use to design adhesive joints. © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the VCSI1 organizers t ti . ., iti l t i l t i t i , I , , II . i i t t li l i i t , it i i l l t t ti t t iti . i t i t l t i t i l i t t i it l it ® , t t t i t ti . t i , t i t l t li t ti t t t il I t II . i t t i l i t t l l t l t i l il it i i i t t l it . , t t il i l l t i t i t i t t . ll, t t t ti t i t i . l l t i , lti i l t l i t t i t i l t i ti t t l i i l t i i j i t . t . P li l i . . is is an open access article under the CC BY-NC-ND license ( tt :// ti . /li / nc-nd/4.0/) Pe i i ilit t i 1st Virtual Conference on Structural Integrity - VCSI1 Mixed-mode fracture toughness of a structural adhesive by the single-leg bending test F.J.C.F.B. Loureiro a , R.D.S.G. Campilho a,b *, R.J.B. Rocha a,b a Departamento de Engenharia Mecânica, Instituto Superior de Engenharia do Porto, Instituto Politécnico do Porto, Rua Dr. António Bernardino de Almeida, 431, 4200-072 Porto, Portugal b INEGI – Pólo FEUP, Rua Dr. Roberto Frias, s/n, 4200-465 Porto, Portugal a a,b a,b a t t i i , tit t i i t , tit t lit i t , . t i i l i , , t , t l b l , . t i , / , t , t l Abstract i t i i t i i t t , it i i t t t l t t l i t t i t t

Keywords: Epoxy/epoxides; Polyurethane; Fracture; Composites; Bonded joint; Mixed-mode. i ; l t ; t ; it ; j i t; i . /

* Corresponding author. Tel.: +351939526892; fax: +351228321159. E-mail address: raulcampilho@gmail.com i t . l.: ; : . il l il il.

2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the VCSI1 organizers l i . . i i ti l t li tt :// ti . /li / / . / i i ilit t i t . li

2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of the VCSI1 organizers 10.1016/j.prostr.2020.04.010