Assignment#3: Numeric: Investigate elastic anisotropy of a unidirectional Alumina/PEEK composite.


Assignment #3: (200pnts)
Numeric: Investigate elastic anisotropy of
a unidirectional Alumina/PEEK composite.


Objective: Setup a problem for students to investigate anisotropy of a unidirectional fiber-reinforced composite made from alumina fibers and Polyether-ether-ketone (PEEK) polmyer matrix by using the Interactive Modules embedded in the lecture notes.
Prerequisites for Student: Lectures based on material in section 4.1 Introduction to Mechanical Behavior of Anisotropic Materials. Two unpublished manuscripts on elastic properties of Alumina/PEEK will be passed out in class.

From lecture notes and two unpublished manuscripts on Alumina/PEEK and access to interactive computer program modules # 2, 3, 19, and 20, follow the outline below:

From Table 1. in Handout#1, compare composite properties at a given fiber volume fraction with those calculated in Table 1. Compare the anisotropy of the Alumina/PEEK with the graphite/epoxy default in Module#2, for example is there, or is there a trend toward negative Poisson's ratio. What if any role does the micro- / nano-structure control the macroscopic anisotropy.

Take the elastic composite properties and substitute them into Modue#3 and view the elastic anisotropy as eigen-value ("shapes") and eigenvector ("color gradients") mapped onto the wave surface. Again how does Alumina/PEEK compare with the anisotropy of the graphite/epoxy.

Also take the same elastic composite properties and substitute them into Module#19 and Module#20 and investigate the effect this anisotropy has on the dynamic mechanical behavior. Again compare these results with graphite/epoxy.

Explain in your own words how elastic properties scale from nano to macro as illustrated in Fig. 23 at the end of section 4.1 on "Geometric Representations of Elastic Anisotropy: All Tensor Components, Cijkl. Include results from your Alumina/PEEK in your discussion.

Include a copy of your results from each the modules that includes the "unique-directory" name that lists all files. Also include images of your results as part of your discussion.

Handouts:

  1. Elastic Constants of a Al2O3-SiOs (fiber)/ PEEK Composite: Measurements, Modeling, and Low Temperatures.

  2. Performance of Alumina/Epoxy Thermal Isolation Straps.

Contact Dr Ron Kriz for information in this section.
Created 11/08/00 | Revised 11/08/00
http://www.jwave.vt.edu/~rkriz/crcd/assign/assign3/assign3.html