Development of Novel Skin Materials for Morphing Aircraft

Abstract

This project explored development of 'skin' material for morphing structures. Flexible fiber-reinforced composites are the prime candidates for morphing skins in order to achieve the required elongation and strength. Main objective was to develop a woven or cross ply fabric that can exhibit extension as well as shear deformations by developing and incorporating hyper-elastic yarns. These yarns consist of low modulus elastomeric core braided with high-modulus fibers. Low-modulus phase allows significant area change during deployment, and the high modulus stage provides the necessary stiffness to the skin after deployment. The 'knee-point' can be tuned to the desired strain necessary for the application by altering the manufacturing settings. In this work, two different hyper-elastic yarns were produced: biaxial braids and triaxial braids. Tensile testing showed the deformation processes to be similar. However, due to the style of interlacement, triaxial yarns achieved larger extensions. Both the styles of yarn are suitable for morphing skin applications. In addition, various braided yarns were developed by changing the pre-tension on the elastane yarn to produce different braid angles. The knee-point between low modulus and high modulus behavior was shown to shift based on braid angle, allowing a means of tuning the desired strain. A computational model for predicting the load-strain behavior of hyper-elastic yarns was developed and shown to agree well with experimental results. Finally, a woven composite was manufactured and tested as a morphing skin material using the braided yarns, and compared to analytical mechanics-based predictions.

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Document Details

Document Type
Technical Report
Publication Date
Nov 19, 2010
Accession Number
ADA534980

Entities

People

  • Haseeb Arshad
  • Raj Ramgulam
  • Sabahat Nawaz
  • Venkata P. Potluri

Organizations

  • University of Manchester

Tags

Communities of Interest

  • Air Platforms
  • Space

DTIC Thesaurus Topics

  • Air Force Research Laboratories
  • Aircrafts
  • Composite Materials
  • Deployment
  • Differential Equations
  • Elongation
  • Equations
  • Fibers
  • Geometry
  • Manufacturing
  • Materials
  • Materials Testing
  • Mechanics
  • Stiffness
  • Stress Strain Relations
  • Swept Wings
  • Tensile Testing

Readers

  • Materials Science.
  • Polymer Science and Engineering.
  • Structural Health Monitoring of Composite Structures.