Mixed mode properties of CNT reinforced composites using Arcan test rig
Jacob MUTHU()
DST-NRF Centre of Excellence in Strong Materials and RP/Composite Facility, School of Mechanical, Industrial and Aeronautical Engineering, University of the Witwatersrand, Johannesburg, South Africa
Composite materials reinforced with carbon nanotubes were mechanical tested using Arcan test rig under Mode-I, Mode-II and mixed mode loading conditions to obtain their fracture properties. The butterfly composite specimens were fabricated with 0.02, 0.05 and 0.1 wt % CNTs. The polyester/CNT composite was fabricated using VRTM (Vacuum Resin Transfer Molding) where the CNTs were first functionalised to reach an optimum properties. Arcan test rig was designed and fabricated to work with the Shimadzu testing machine. The results show that the functionalised CNTs have improved the fracture behavior by acting as bridge between the cracked face. In addition, the fracture properties were not improved for the higher weight fraction of 0.1 wt% CNTs.
Muthu J, Dendere C. Functionalized multiwall carbon nanotubes strengthen GRP hybrid composite: Improved properties with optimum fibre content. Composite Part B, 2014, 67: 84–94
2
Jacob Muthu S D, Paskaramoorthy R. Double-Wall Carbon Nanotube-Reinforced Polyester Nanocomposites: Improved Dispersion and Mechanical Properties. Polymer Composites, 2012, 33(6): 866–872
3
Karapappas P, Vavouliotis A, Tsotra P, Kostopoulos V, Paipetis A. Enhanced Fracture Properties of Carbon Reinforced Composites by the Addition of Multi-Wall Carbon Nanotubes. Journal of Composite Materials, 2009, 43(9): 977–985
4
Wilkins D J, Eisenmann J R, Camin R A, Margolis W S, Benson R A. Characterizing Delamination Growth in Graphite-Epoxy. Damage in Composite Materials, ASTM STP 775, K. L. Reifsnider, ed. American Society for Testing and Materials, Philadelphia, 1982, 168–183
5
American Society for Testing and Materials. Standard E399−06, Standard Test Method for Linear-Elastic Plane-Strain Fracture Toughness KIC of Metallic Materials. Annual Book of ASTM Standards. Philadelphia: ASTM, 2007
6
Russell A J. On the Measurement of Mode II Interlaminar Fracture Energies, DREP Materials Report. 82−0, Defence Research Establishment Pacific, Victoria, December, 1982
7
O'Brien T K. Mixed-Mode Strain-Energy-Release Rate Effects on Edge Delamination of Composites, Effects of Defects in Composite Materials, ASTM STP 836, D. J. Wilkins, ed. American Society for Testing and Materials, Philadelphia, 1984, 125–142
8
Wolfenden A, Johnson W S. Stress analysis of the crack-lap-shear specimen: An ASTM round-robin. Journal of Testing and Evaluation, JTEVA, 1987, 15(6): 303–324
9
Banks-Sills L, Arcan M, Gabay H. A mode II fracture specimen-finite element analysis. Engineering Fracture Mechanics, 1984, 19(4): 739–750
10
El-Hajjar R, Haj-Ali R, 0. Rami Haj-Ali. In-plane shear testing of thick-section pultruded FRP composites using a modified Arcan fixture. Composite Part B, 2004, 35(5): 421–428
11
ASTM E399. Standard Test Method for Plane Strain Fracture Toughness and Strain Energy Release Rate of Metalic Materials: Annual Book of ASTM Standards, 1983
12
ASTM D5045. Standard Test Method for Plane Strain Fracture Toughness and Strain Energy Release Rate of Plastic Materials: Annual Book of ASTM Standards, 1995
13
Ayatollahi M R, Shadlou S, Shokrieh M M. Mixed mode brittle fracture in epoxy/multi-walled carbon nanotube nanocomposites. Engineering Fracture Mechanics, 2011, 78(14): 2620–2632