PSI - Issue 25

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

www.elsevier.com/locate/procedia .elsevier.co /locate/procedia

ScienceDirect

Procedia Structural Integrity 25 (2020) 400–412

© 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 Failure induced by fiber microbuckling is a frequent failure mode in continuous fiber-reinforced composite materials subjected to compression along the fibers direction. This failure mechanism may lead to a notable decrease of the compressive strength of composite materials since may also induce the initiation and propagation of cracks at the micro-structural level. A detailed microscopic continuum analysis with an appropriate representation of different sources of nonlinearities is usually required to capture the effects of different microscopic failure modes (instability, fracture damage, for instance), at the expense of a very large computational effort. In order to avoid a direct modeling of all microstructural details of the composite solid, micromechanically based multiscale techniques can be adopted in coupling with first order homogenization schemes. To this end a semiconcurrent two-scale approach is proposed in which the macroscopic constitutive law is evaluated resolving a micromechanical BVP in each macroelement of the homogenized domain; the microscopic model adopts a full finite deformation continuum formulation to study the interaction between local fiber buckling and matrix or fiber/matrix interface microcracks in presence of unilateral self-contact between crack surfaces. Numerical results are obtained to provide accurate predictions of the critical load level associated to microscopic instabilities in 2D fiber-reinforced composite solids. © 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 ail re i ce fi er icr c li is a fre e t fail re e i c ti s fi er-rei f rce c site aterials s jecte t c ressi al t e fi ers irecti . is failure ec a is a lea t a ta le ecrease f t e c ressi e stre t f c site aterials si ce a als i ce t e i itiati a r a ati f crac s at t e icr -str ct ral le el. etaile icr sc ic c ti a al sis it a a r riate re rese tati f iffere t s rces f li earities is s all re ire t ca t re t e effects f iffere t icr sc ic fail re es (i sta ilit , fract re a a e, f r i sta ce), at t e e e se f a er lar e c tati al eff rt. I r er t a i a irect eli f all icr str ct ral etails f t e c site s li , icr ec a icall ase ltiscale tec i es ca e a te i c li it first r er e izati sc e es. t is e a se ic c rre t t -scale a r ac is r se i ic t e acr sc ic c stit ti e la is e al ate res l i a icr ec a ical i eac acr ele e t f t e e ize ai ; t e icr sc ic el a ts a f ll fi ite ef r ati c ti f r lati t st t e i teracti et ee l cal fi er c li a atri r fi er/ atri i terface icr crac s i rese ce f ilateral self-c tact et ee crac s rfaces. erical res lts are tai e t r i e acc rate re icti s f t e critical l a le el ass ciate t icr sc ic i sta ilities i fi er-rei f rce c site s li s. e t rs. lis e lse ier . . is is an ope access article er t e - - lice se ( tt ://creati ec s. r /lice ses/ - c- / . /) er-re ie er res si ilit f t e I r a izers 1st Virtual Conference on Structural Integrity - VCSI1 Nonlinear analysis of microscopic instabilities in fiber-reinforced composite materials Umberto De Maio, Fabrizio Greco * , Lorenzo Leonetti, Andrea Pranno, Girolamo Sgambitterra Department of Civil Engineering, University of Calabria, Via P. Bucci Cubo39B, Rende 87036, Italy t irt l f r tr t r l I t rit - I t M i , i i * , tti, , i l itt epart ent of ivil ngineering, niversity of alabria, ia . ucci ubo39 , ende 87036, Italy Abstract str ct

Keywords: Fiber-reinforced composite; Finite strain homogenization; Self-contact mechanics; Buckling instability; Multiscale analysis. ey ords: iber-reinforced co posite; inite strain ho ogenization; elf-contact echanics; uckling instability; ultiscale analysis.

* Corresponding author. Tel.: +390984496916. E-mail address: fabrizio.greco@unical.it * orresponding author. el.: 390984496916. - ail address: fabrizio.greco unical.it

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 2452-3216 2020 he uthors. ublished by lsevier . . his is an open access article under the - - license (http://creativecommons.org/licenses/by-nc-nd/4.0/) eer-revie under responsibility of the I1 organizers

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.2020.04.045