A Three-Dimensional Stress Analysis of Woven Fabric Composites Based on a Mixed Variational Model and Spline Approximation
Abstract
The stiffness of fabric (woven) composites has been well studied. However, the failure mechanism of this class of composites is not well understood. The prediction of the stiffness of woven composites is relatively simple compared to the prediction of strength, and has been done extensively in the literature. It is known that the yarn crimping in woven fabric composites plays an important role in the failure initiation process. In the vicinity of yarn crimping of two-dimensional fabric (woven) architecture, two perpendicular yarns crimp over and under to each other. Due to the perpendicular yarn crimping, even under the application of simple unidirectional load, the stresses in the vicinity of the yarn crimping are three dimensional. Further, in situ experimental observation of damage initiation in textile composites reveals that the damage initiates in the form of interface cracks in the vicinity of yarn crimping, which is strongly influenced by the interlaminar stresses at the interface region. Thus an accurate prediction of the interlaminar stresses at the interface region is needed to reliably analyze damage and failure in woven composites. Most of the research work in this area, however, is based on two-dimensional stress analysis which does not reliably predict the interlaminar stresses. Further, traditional displacement-based finite-element analysis only predicts stresses accurate at the Gaussian integration points; thus, even three-dimensional finite element analysis does not yield accurate interlaminar stresses at the interface.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 15, 1998
- Source ID
- 10.1115/imece1998-1180
Entities
People
- A. K. Roy
Organizations
- Air Force Research Laboratory