A model for composite laminate bend-forming under arbitrary curvature distribution and extensive interlaminar sliding
✍ Scribed by Margaret F. Talbott; Alan K. Miller
- Publisher
- Society for Plastic Engineers
- Year
- 1990
- Tongue
- English
- Weight
- 924 KB
- Volume
- 11
- Category
- Article
- ISSN
- 0272-8397
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✦ Synopsis
Abstract
While thermoplastic matrix composites are of increasing interest for a variety of applications, methods of forming these materials are still under development. One way of hastening their development and utilization is to develop models which predict the material response to processing. One such model is under development and will predict the response of a consolidated laminate which is being formed to a singly‐curved shape. The model accounts for the unique features of thermoplastic composites, namely the continuous inextensible fibers and the need for extensive relative ply sliding. At this stage in model development, it treats a laminate as a series of alternating layers of elastically hard and elastically soft material. The hard layers can slide over each other because of the soft shearable layers between them. In its present stage, the model predicts, for any arbitrarily complex singly‐curved shape, the extent of relative ply sliding, the stresses generated, and the array of point forces that are required to produce the specified shape. The behavior of a beam with extensive ply sliding is very different from that described by classical beam theory. First, the ply normal stresses depend not only on the local curvature and distance from the neutral axis, but also on the position along the laminate. Second, the relative ply sliding and the bending stresses occur not only in bent sections of the laminate, but also in nearby straight sections. Thus, the response of a given element of material depends not only on local conditions, but also on the curvature distribution throughout the laminate.