Authors: Zhimin Xi Byeng D Youn
Publish Date: 2012/04/11
Volume: 26, Issue: 4, Pages: 1089-1097
Abstract
It has been reported that a carbon nanotube CNT is one of the strongest materials with its high failure stress and strain Moreover the nanotube has many favorable features such as high toughness great flexibility low density and so on This discovery has opened new opportunities in various engineering applications for example a nanocomposite material design However recent studies have found a substantial discrepancy between computational and experimental material property predictions in part due to defects in the fabricated nanotubes It is found that the nanotubes are highly defective in many different formations eg vacancy dislocation chemical and topological defects Recent parametric studies with vacancy defects have found that the vacancy defects substantially affect mechanical properties of the nanotubes Given random existence of the nanotube defects the material properties of the nanotubes can be better understood through statistical modeling of the defects This paper presents predictive CNT models which enable to estimate mechanical properties of the CNTs and the nanocomposites under various sources of uncertainties As the first step the density and location of vacancy defects will be randomly modeled to predict mechanical properties It has been reported that the eigenvector dimension reduction EDR method performs probability analysis efficiently and accurately In this paper molecular dynamics MD simulation with a modified Morse potential model is integrated with the EDR method to predict the mechanical properties of the CNTs To demonstrate the feasibility of the predicted model probabilistic behavior of mechanical properties eg failure stress failure strain and toughness is compared with the precedent experiment resultsZhimin Xi is a Research Assistant Professor in the Department of Industrial and Manufacturing Systems Engineering at the University of Michigan — Dearborn He received his BS and MS degree in mechanical engineering from Beijing University of Science and Technology and his PhD from University of Maryland — College Park He is the onetime winner of the Best Paper Award from ASME International Design Engineering Technical Conference IDETC in 2008 His research interests are robust/reliability based design multiscale materials and product design and model validation verificationByeng D Youn is an Assistant Professor in the School of Mechanical and Aerospace Engineering at Seoul National University South Korea He received his BS degree in mechanical engineering from Inha University his MS degree in mechanical engineering from KAIST Korea and his PhD from the University of Iowa USA He is the twotime winner of the Best Paper Award from ASME International Design Engineering Technical Conference IDETC in 2001 and 2008 His research interests include computer model verification and validation prognostics and health management reliability analysis and reliabilitybased design and energy harvester design
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