PSI - Issue 25

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2019) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000–000 Available online at www.sciencedirect.com ScienceDirect

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

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Procedia Structural Integrity 25 (2020) 3–7

1st Virtual Conference on Structural Integrity - VCSI1 Experimental and Analytical Study of the Hyperelastic Behavior of the Hydrogel under Unconfined Compression 1st Virtual Conference on Structural Integrity - VCSI1 Experimental and Analytical Study of the Hyperelastic Behavior of the Hydrogel under Unconfined Compression

Hassan Mansour Raheem a,* , A.M. Al-Mukhtar b a Mechanical Department, Faculty of Engineering, University of Kufa, Najaf, Iraq a Ministry of Oil, Midland Refineries Company, Najaf Refinery, Najaf, Iraq b Biomedical Engineering Dept., College of Engineering, University of Warith Alanbiyaa, Iraq b Vff, TUBA Freiberg, 09599 Freiberg, Germany Hassan Mansour Raheem a,* , A.M. Al-Mukhtar b a Mecha ical Department, Faculty of Engineeri g, University of Kufa, Najaf, Iraq a Ministry of Oil, Midland R fineries Compa y Najaf Refinery, Najaf, Iraq b Biomedical Engineering Dept., Coll ge of Engineering, University of Warith Alanbiyaa, Iraq b Vff, TUBA Freiberg, 09599 Freiberg, Germany

© 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 © 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 Abstract Hydrog ls ha e b en studied for replaci g th deg nerative nucleus pulpousus (NP) due to their biocompat bilities and they resemble th viscoelastic properties f t e native tissue. The mec anical b havior of these materials under nconfin d compr ssion that exhibited the non-linear b havior h not en in ens ly highlighted. Th goal of this study is to utilize t e strain energy density functions (SEDFs) to de ermine a suitabl con titutive model th t repr sents the n nlinear behavior of the hydrogels under unconfined c mpression t st. In this context, yperelastic mod ls, such a O den, Neo-Hooke n, M oney-Rivlin and Ye h mod ls are selected t fit th experimental data for the hyd ogels. The aim of using these models is also to p edict the b havior of th se materials out of range of the st (i.e. n tension). Th fore, FEA u ing ABAQUS/CAE is adopted to verify the hyperela tic models in compre sion an to validate the abil ty of the hyperelastic models of predicting the nonlin ar b havior of the hydro ls in ensi n. The resul s showed that all hyperelastic models are fitted the exp rim nt l data and the pr dicted results by FEA agree wit those of the est data. Ogden (N=1) model has well defined the nonlinear behavior of those types of material and was used in the FEA simulation. © 2020 The Authors. Published by Elsevier B.V. This is an ope acces article under C BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Abstract Hydrogels have been studied for replacing the degenerative nucleus pulpousus (NP) due to their biocompatibilities and they resemble the viscoelastic properties of the native tissue. The mechanical behavior of these materials under unconfined compression that exhibited the non-linear behavior has not been intensively highlighted. The goal of this study is to utilize the strain energy density functions (SEDFs) to determine a suitable constitutive model that represents the nonlinear behavior of the hydrogels under unconfined compression test. In this context, hyperelastic models, such as Ogden, Neo-Hookean, Mooney-Rivlin and Yeoh models are selected to fit the experimental data for the hydrogels. The aim of using these models is also to predict the behavior of these materials out of range of the test (i.e. in tension). Therefore, FEA using ABAQUS/CAE is adopted to verify the hyperelastic models in compression and to validate the ability of the hyperelastic models of predicting the nonlinear behavior of the hydrogels in tension. The results showed that all hyperelastic models are fitted the experimental data and the predicted results by FEA agree with those of the test data. Ogden (N=1) model has well defined the nonlinear behavior of those types of material and was used in the FEA simulation.

Peer-review under responsibility of the VCSI1 organizers

Keywords: Agarose; Biomaterials; Compression test; Hyperelastic models; Hydrogels; Polymer Keywords: Agarose; Biomaterials; Compression test; Hyperelastic models; Hydrogels; Polymer

* Corresponding author. E-mail address: raheemh@oregonstate.edu * Corresponding author. E-mail address: raheemh@oregonstate.edu

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 The Authors. Published by Elsevier B.V. This is an ope acces article under C BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Peer-review under responsibility of the VCSI1 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.2020.04.002