Composites Reinforced with Short Wavy Fibers
Abstract
In short fiber composites including nanocomposites, the load transfer efficiency among fibers is crucial in effecting superior composite properties. It is conceivable that this load transfer efficiency depends on the shape, aspect ratio, and surface area of the fiber. The effect of surface area of the reinforcing element is of particular importance because of the increasing use of nanoparticles in nanocomposites. It is well known that for the some volume, a material at nanoscale possesses much greater surface areas than at larger scales. It is evident that more surface areas mean more load transfer paths and, thus, lower interfacial stresses between the reinforcement and the matrix. The lowering of interfacial stresses is expected to lead to higher composite strengths. In this research project we used model composites to reach the following conclusions: 1) Wavy fibers lower the interfacial stresses and thus increase the composite strength significantly; 2) for the same fiber volume fraction, the composite with thinner fibers has higher strength than the composite with thicker fibers, 3) result of fiber (platelet) pull-out tests indicates that thinner fibers gave a higher pull out strength than thicker fibers. The increase was about 30% for each 50% reduction in the thickness of the fiber, 4) the Young's modulus of a particulate composite is not influenced by the size of the particle if it is of micron or larger sizes. However, the composite Young's modulus is enhanced with decreasing particle sizes at nano scale. This behavior was explained by using molecular dynamics simulations which revealed that this enhancement of modulus by nanoparticles may be attributed to a stiffer polymer layer formed around nanoparticles.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2006
- Accession Number
- ADA443834
Entities
People
- A. Deo
- Chintech Sun
- J. Cho
Organizations
- Purdue University