Investigation of damage initiation and propagation in 2 x 2 twill woven carbon/epoxy multi-layer composites

Karahan M.

TEXTILE RESEARCH JOURNAL, vol.81, no.4, pp.412-428, 2011 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 81 Issue: 4
  • Publication Date: 2011
  • Doi Number: 10.1177/0040517510395996
  • Journal Name: TEXTILE RESEARCH JOURNAL
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.412-428
  • Keywords: 2 x 2 twill woven composites, acoustic emission, damage, full-field strain measurement, mechanical properties, BRAIDED TEXTILE COMPOSITES, 3D ORTHOGONAL WEAVE, TENSILE PROPERTIES, PART 1, FAILURE ANALYSIS, BEHAVIOR
  • Bursa Uludag University Affiliated: Yes

Abstract

Damage and mechanical properties in textile composites are closely connected with the textile reinforcement's internal structure. This paper reports and discusses a study of the mechanical behavior and damage of a 2 x 2 twill woven carbon/ epoxy composite resulting from uniaxial tension in the warp and bias directions. A damage investigation was performed by using acoustic emission and full-field strain optical measurements, as well as X-ray and optical microscopy. As a result of the tests, the mechanical properties and strain values of the composite's damage threshold were determined. Damage initiation when loaded in the warp and bias directions occurred between 0.2% and 0.3% and 0.88% and 1.71% of the applied strain, respectively. Microscopic examination showed that damage or cracks initiated where the yarn was crimped and at interactions between the warp and filling yarns. Full-field strain measurements highlighted the relation between the strain concentrations that are linked with the damage initiation and the reinforcement structure.