Abstract
The concept of a feature matrix is introduced that is based on the coefficient values utilized in anistropic elasticity. The feature values inside the feature matrix, which could quite often simply be the stiffness coefficients of the material, are used to carry out nondestructive evaluation analysis of the material in determining material properties, anisotropy, inhomogeneity, defect presence, and possible stress state. An inverse surface wave velocity technique is used to study the generation of feature matrices from material, geometrical, and elastic constant computations for the practical Nondestructive Evaluation of Composite Materials. Theoretical modelling work is carried out to illustrate the wave velocity changes as a function of angle with respect to the axes along the fibers of a unidirectional graphite epoxy composite material for a variety of different problems in nondestructive evaluation, including porosity changes, fiber volume fraction changes and delamination. Experiments are also conducted on a unidirectional and (0-90)s cross ply graphite epoxy test to illustrate the wave velocity measurements and inverse computation procedure for evaluation of the stiffness coefficients.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 117-131 |
| Number of pages | 15 |
| Journal | American Society of Mechanical Engineers, Applied Mechanics Division, AMD |
| Volume | 90 |
| State | Published - 1988 |
| Event | The Joint ASME/SES Applied Mechanics and Engineering Sciences Conference - Berkeley, CA, USA Duration: Jun 20 1988 → Jun 22 1988 |
All Science Journal Classification (ASJC) codes
- Mechanical Engineering