PSI - Issue 37

Available online at www.sciencedirect.com Av ilable o line at w.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000

www.elsevier.com/locate/procedia

ScienceDirect ScienceDirect

Procedia Structural Integrity 37 (2022) 485–491 Structural Integrity Procedia 00 (2019) 000 – 000

www.elsevier.com/locate/procedia

© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Pedro Miguel Guimaraes Pires Moreira Abstract During the last decades, composites had been successfully strengthened at the micrometer scale using different types of reinforcements, e.g., carbon or even glass fibers. Over the past years, the development of carbon nanotubes and graphene enabled the reinforcement of cement-based materials at the nanoscale. The produced nanocomposites have increased the mechanical properties as compared to non- reinforced materials and especially on the “effective” properties such as modulus of elasticity and Poisson ’s ratio. In several c ases and for compatibility issues, it is of imperative importance to “tailor” a nano -reinforced composite with specific material properties, such as the modulus of elasticity and the Poisson ’s ratio. To this end, a methodology to identify the optimal material synthesis needs to be effectively addressed. The present article presents an optimization method to quantify the appropriate volume fraction of graphene nanostructures to design a cement-based nanocomposite with a target value of the effective modulus. The Interior Point Optimization (IPOpt) algorithm is used for the optimization iterations applied to the homogenization properties calculated by ANSA ® pre-processor. A comparison was made between three different optimization cases, having different maximum number of iterations and a different objective value. The calculated effective modulus and volume fraction were correlated with the target experimental values. Keywords: optimization; nanocomposites; multi-step method; homogenization Abstract During the last decades, composites had been successfully strengthened at the micrometer scale using different types of reinforcements, e.g., carbon or even glass fibers. Over the past years, the development of carbon nanotubes and graphene enabled the reinforcement of cement-based materials at the nanoscale. The produced nanocomposites have increased the mechanical properties as compared to non- reinforced materials and especially on the “effective” properties such as modulus of elasticity and Poisson ’s ratio. In several c ases and for compatibility issues, it is of imperative importance to “tailor” a nano -reinforced composite with specific material properties, such s the modulus of elasticity and the Poisson ’s ratio. To this e d, a methodology to identify t optimal material synth sis needs to be effectively addressed. present article presents an optimization method to qu tify the appropriate volume fraction of graphene nanostructures to design a cement-based nanocomposite with a target value of the effective modulus. The Interior Point Optimization (IPOpt) algorithm is used for the optimization iteratio s applied to th homogenization properties calculated by ANSA ® pre-processor. A comparison was made between three different optimization cases, having different maximum number of iterations and a different objective value. Th calculated effective modulus and volume fraction were correlated with the tar et experimental val es. Keywords: optimization; nanocomposites; multi-step method; homogenization e Department of Financial and Management Engineering, University of the Aegean , Kountouriotou Str., 82100, Chios, Greece, nalexop@aegean.gr c Department of Chemistry, International Hellenic University, St. Luke, 65404, Kavala, Greece, zmetaxa@chem.ihu.gr e Department of Financial and Management Engineering, University of the Aegean , Kountouriotou Str., 82100, Chios, Greece, alexop@aegean. r d Department of Product and Systems Design Engineering, University of the Aegean , Konstantinoupoleos 1, Ermoupoli, 84100, Syros, Greece, ppap@syros.aegean.gr ICSI 2021 The 4th International Conference on Structural Integrity Optimization of the carbon nanotubes reinforcement in cement based materials Anastopoulos G. Stylianos a , Givannaki Th. Faidra b , Metaxa S. Zoi c , Papanikos Paraskevas d , Alexopoulos D. Nikolaos e * a Department of Financial and Management Engineering, University of the Aegean, 41 Kountouriotou Str., 82100, Chios, Greece, fmer18001@fme.aegean.gr ICSI 2021 The 4th International Conference on Structural Integrity Optimization of the carbon nanotubes reinforcement in cement based materials Anastopoulos G. Stylianos a , Givannaki Th. Faidra b , Metaxa S. Zoi c , Papanikos Paraskevas d , Alexopoulos D. Nikolaos e * a Department of Financial and Management Engineering, University of the Aegean, 41 Kountouriotou Str., 82100, Chios, Greece, fmer18001@fme.aegean.gr b BETA CAE Systems SA, Kato Scholari, Thessaloniki GR-57500 Epanomi, Greece, p.givannaki@beta-cae.com c Department of Chemistry, International Hellenic University, St. Luke, 65404, Kavala, Greece, zmetaxa@chem.ihu.gr b BETA CAE Systems SA, Kato Scholari, Thessaloniki GR-57500 Epanomi, Greece, p.givannaki@beta-cae.com d Department of Product and t Design Enginee ng, Univers ty of the Aegean , Konstantinou oleos 1, Ermoupoli, 84100, Syros, Greece, ppap@syros.aegean.gr

2452-3216 © 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Pedro Miguel Guimaraes Pires Moreira 10.1016/j.prostr.2022.01.113 2452-3216 © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Pedro Miguel Guimaraes Pires Moreira 2452-3216 © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Pedro Miguel Guimaraes Pires Moreira