Title: Finite element simulation of single carbon nanotube pull-outs from a cementitious nanocomposite material using an elastic-plastic-damage and cohesive surface models

Authors: Rashid K. Abu Al-Rub; Sun-Myung Kim; Khaldoon A. Bani-Hani; Nasser Al-Nuaimi; Ahmed Senouci

Addresses: Department of Mechanical and Materials Engineering, Institute Center for Energy, Masdar Institute of Science and Technology, Abu Dhabi, UAE ' Research Team1, R&D Division, Hankook Tire Co., LTD., Daejeon, Korea ' Department of Civil Engineering, Jordan University of Science and Technology, Irbid, Jordan ' Department of Civil and Architectural Engineering, Qatar University, Doha, Qatar ' Department of Construction Management, University of Houston, Houston, TX 77204-4020, USA

Abstract: Carbon nanotubes (CNTs) have recently been integrated in the most widely used material in the world 'concrete' for improving its mechanical properties and fracture resistance. This paper computationally investigates the pull-out behaviour of a single CNT from cement. The effects of: 1) CNT-cement interfacial shear strength, stiffness, and fracture energy; 2) the cement mechanical properties; 3) CNT's mechanical properties, aspect ratio, and surface area to volume ratio on the pull-out strength from a cement matrix are investigated through simulating the single straight CNT pull-out. A coupled elastic-plastic-damage constitutive model is adopted to simulate the behaviour of the cement matrix, whereas the continuum shell model is used to simulate the elastic behaviour of CNT. The surface-based cohesive behaviour is employed for modelling the interface between CNT and cement matrix. It is shown that CNT pull-out is mainly governed by the interfacial fracture energy, and not the interfacial shear strength.

Keywords: cementitious nanocomposites; debonding; interfacial fracture energy; interfacial damage; cement damage; nanotechnology; finite element method; FEM; simulation; carbon nanotubes; CNTs; elastic-plastic-damage constitutive models; surface modelling; pull-out behaviour; interfacial shear strength; stiffness; mechanical properties; continuum shell models; elastic behaviour.

DOI: 10.1504/IJTAMM.2014.069448

International Journal of Theoretical and Applied Multiscale Mechanics, 2014 Vol.3 No.1, pp.31 - 57

Received: 30 May 2014
Accepted: 19 Feb 2015

Published online: 16 May 2015 *

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