The combination of materials to form a new material system with enhanced material properties is a well documented historical fact. For example, the ancient Jewish workers during their tenure under the Pharaohs used chopped straws in bricks as a means of enhancing their structural integrity. The Japanese Samurai warriors were known to use laminated metals in the forging of their swords to obtain desirable material properties. Even certain artisans from the Mediterranean and Far East used a form of composite technology in molding art works which were fabricated by layering cut paper in various sizes for producing desired shapes and contours.

Introduction To Composite Materials

Publisher Summary This chapter describes the mixed mode cracking in layered materials. There is ample experimental evidence that cracks in brittle, isotropic, homogeneous materials propagate such that pure mode I conditions are maintained at the crack tip. An unloaded crack subsequently subject to a combination of modes I and II will initiate growth by kinking in such a direction that the advancing tip is in mode I. The chapter also elaborates some of the basic results on the characterization of crack tip fields and on the specification of interface toughness. The competition between crack advance within the interface and kinking out of the interface depends on the relative toughness of the interface to that of the adjoining material. The interface stress intensity factors play precisely the same role as their counterparts in elastic fracture mechanics for homogeneous, isotropic solids. When an interface between a bimaterial system is actually a very thin layer of a third phase, the details of the cracking morphology in the thin interface layer can also play a role in determining the mixed mode toughness. The elasticity solutions for cracks in multilayers are also elaborated.

Mixed mode cracking in layered materials

Polymer-based composites were heralded in the 1960s as a new paradigm for materials. By dispersing strong, highly stiff fibres in a polymer matrix, high-performance lightweight composites could be developed and tailored to individual applications. Today we stand at a similar threshold in the realm of polymer nanocomposites with the promise of strong, durable, multifunctional materials with low nanofiller content. However, the cost of nanoparticles, their availability and the challenges that remain to achieve good dispersion pose significant obstacles to these goals. Here, we report the creation of polymer nanocomposites with functionalized graphene sheets, which overcome these obstacles and provide superb polymer-particle interactions. An unprecedented shift in glass transition temperature of over 40 degrees C is obtained for poly(acrylonitrile) at 1 wt% functionalized graphene sheet, and with only 0.05 wt% functionalized graphene sheet in poly(methyl methacrylate) there is an improvement of nearly 30 degrees C. Modulus, ultimate strength and thermal stability follow a similar trend, with values for functionalized graphene sheet- poly(methyl methacrylate) rivaling those for single-walled carbon nanotube-poly(methyl methacrylate) composites.

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Functionalized graphene sheets for polymer nanocomposites

Recent advances in graphene based polymer composites

https://cyberleninka.org/article/n/1018032.pdf

Polymer nanotechnology: Nanocomposites

Engineering Mechanics of Composite Materials, 2/e analyzes the behavior and properties of composite materials-rigid, high-strength, lightweight components that can be used in infrastructure, aircraft, automobiles, biomedical products, and a myriad of other goods. This edition features additional exercises and new material based on the author's research and advances in the field.

Isaac M. Daniel

Papers

Engineering Mechanics of Composite Materials

Characterization and modeling of mechanical behavior of polymer/clay nanocomposites

Mechanical and thermal properties of graphite platelet/epoxy composites

Composite Materials, Testing and Design

Processing of expanded graphite reinforced polymer nanocomposites