Next Article in Journal
Sustainable Composite Fused Deposition Modelling Filament Using Post-Consumer Recycled Polypropylene
Next Article in Special Issue
Polylactic Acid (PLA)/Cellulose Nanowhiskers (CNWs) Composite Nanofibers: Microstructural and Properties Analysis
Previous Article in Journal
Effect of the Chemical Composition of Simulated Body Fluids on Aerogel-Based Bioactive Composites
Previous Article in Special Issue
A Comparative Analysis of the Reinforcing Efficiency of Silsesquioxane Nanoparticles versus Apatite Nanoparticles in Chitosan Biocomposite Fibres
Article Menu

Export Article

Open AccessArticle
J. Compos. Sci. 2017, 1(2), 16; https://doi.org/10.3390/jcs1020016

Computational Study of the Effects of Processing Parameters on the Nonlinear Elastoplastic Behavior of Polymer Nanoclay Composites

Department of Mechanical Engineering, North Dakota State University, Fargo, ND 58108, USA
*
Author to whom correspondence should be addressed.
Received: 29 September 2017 / Revised: 6 December 2017 / Accepted: 7 December 2017 / Published: 9 December 2017
View Full-Text   |   Download PDF [3585 KB, uploaded 9 December 2017]   |  

Abstract

Processing parameters (e.g., exfoliation extent and volume fraction) of clay particles in polymeric resins play a crucial role in the mechanical properties of polymer nanoclay composites (PNCs). This paper is aimed to investigate the effects of clay aspect ratio and volume fraction on the global mechanical properties (e.g., effective stiffness, yield strength, and ultimate tensile strength) of PNCs. During the process, computational micromechanics models are adopted to simulate the nonlinear elastoplastic behavior of the PNCs of varying clay particle volume fractions and aspect ratios subjected to uniaxial tension. A representative volume element (RVE) of the PNCs is employed for the finite-element-method (FEM) based computational simulations. The polymeric matrix is treated as an idealized elastoplastic solid with isotropic hardening behavior, and the clay particles are treated as stiff elastic platelets distributed evenly in the stack and stagger configurations in the matrix. Seven volume fractions (Vf = 0.5%, 1%, 2%, 5%, 7.5%, 10%, and 15%) and seven aspect ratios (the ratio of platelet length over thickness ρ = 1, 2, 5, 10, 20, 50 and 100) of the reinforcing clay particles are utilized. Numerical experiments show that the effective modulus of the PNCs at small strains increases with the increase of either the clay volume fraction or the platelet aspect ratio largely following those predicted by classic micromechanics models. However, at the low particle aspect ratios (e.g., ρ = 1, 2, 5 and 10), the ultimate tensile strength of the clay composite is nearly independent of the clay volume fraction up to 5% in the present study, i.e., the polymeric matrix governs the PNC strength; at the large particle aspect ratios (e.g., ρ = 20 and 50), the ultimate tensile strength is significantly enhanced with growing clay volume fraction higher than 5% and reaches ~150% of that of the polymeric matrix at ρ = 50 and Vf = 10%. A comparative study is conducted for stack and stagger models for the prediction of the mechanical properties of PNCs. It shows that the stack model predicts slightly larger values of the effective stiffness and tensile strength than the stagger model. The numerical study shows that a large platelet aspect ratio through full exfoliation of the clay particles in matrix is crucial to achieving the preferable mechanical properties of PNCs as evidenced in experiments. The present results can be utilized to quantitatively explain the mechanical properties of clay particle-reinforced composites and PNCs within the framework of classic micromechanics, and provide guidelines for computer-aided nanocomposites design for processing property-tailorable PNCs. View Full-Text
Keywords: polymer nanoclay composites (PNCs); mechanical behavior; strength and stiffness; scaling analysis; elastoplastic; finite element analysis (FEA) polymer nanoclay composites (PNCs); mechanical behavior; strength and stiffness; scaling analysis; elastoplastic; finite element analysis (FEA)
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Rahman, A.; Wu, X.-F. Computational Study of the Effects of Processing Parameters on the Nonlinear Elastoplastic Behavior of Polymer Nanoclay Composites. J. Compos. Sci. 2017, 1, 16.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
J. Compos. Sci. EISSN 2504-477X Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top