Share Email Print
cover

Proceedings Paper

Modeling delamination in composite structures by incorporating the Fermi-Dirac distribution function and hybrid damage indicators
Author(s): Anindya Ghoshal; Heung Soo Kim; William H. Prosser; Hsiang Tai; Mark J. Schulz; Goutham Kirikera
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Conventional finite element approaches for modeling delaminations in laminated composite structures use the Heaviside unit step function at the interfacial nodes in the delaminated zone of the structure to model the possible jumps in the displacement field during “breathing” of the delaminated layers. In quantum mechanics, the Fermi-Dirac distribution applies to Fermion particles whose characteristics are half-integer spins. The present paper uses the Fermi-Dirac distribution function to model a smoother transition in the displacement and the strain fields of the delaminated interfaces during the opening and closing of the delaminated layers under vibratory loads. This paper successfully shows that the Fermi-Dirac distribution function can be used to more accurately model the dynamic effects of delaminations in laminated composite structures. Optimizing the parameters in the Fermi-Dirac distribution function can lead to more accurate modeling of the dynamic and transient behavior of the delaminated zones in laminated composite structures. Further applications of the Fermi-Dirac distribution function in other physics based dynamic models are suggested. This paper also effectively demonstrates how hybrid sensors comprising of out of plane displacement sensors and in plane strain sensors can effectively map a composite structure to detect and locate the delaminated zones. It also shows how simple mode shapes can be used to determine the locations of single and multiple delaminations in laminated composite structures.

Paper Details

Date Published: 21 July 2004
PDF: 12 pages
Proc. SPIE 5394, Health Monitoring and Smart Nondestructive Evaluation of Structural and Biological Systems III, (21 July 2004); doi: 10.1117/12.538270
Show Author Affiliations
Anindya Ghoshal, United Technologies Research Ctr. (United States)
Heung Soo Kim, Air Force Institute of Technology (United States)
William H. Prosser, NASA Langley Research Ctr. (United States)
Hsiang Tai, NASA Langley Research Ctr. (United States)
Mark J. Schulz, Univ. of Cincinnati (United States)
Goutham Kirikera, Univ. of Cincinnati (United States)


Published in SPIE Proceedings Vol. 5394:
Health Monitoring and Smart Nondestructive Evaluation of Structural and Biological Systems III
Tribikram Kundu, Editor(s)

© SPIE. Terms of Use
Back to Top