Effect of ply angle misalignment on out-of-plane deformation of symmetrical cross-ply CFRP laminates: Accuracy of the ply angle alignment

Yoshihiko Arao, Jun Koyanagi, Shin Utsunomiya, Hiroyuki Kawada

Research output: Contribution to journalArticle

32 Citations (Scopus)


This paper discusses the accuracy of ply angle alignment and how it relates to out-of-plane deformation in carbon fiber reinforced plastics (CFRP) laminates. We investigated the deformation of symmetrical cross-ply laminates under hot and humid conditions. In spite of the symmetrically stacked laminates, unpredictable out-of-plane deformation occurred over time due to ply angle misalignment. The deformation was unstable and disproportionate to the absorbed moisture. A Monte Carlo simulation based on laminate theory was performed to quantify the deformation induced by the ply angle misalignment. Symmetrical cross-ply laminates were found to twist as they absorbed water when they underwent ply angle misalignments. By comparing the analytical results with experimental results, we concluded that a standard deviation of approximately 0.4° exists as ply angle misalignment in the laminates used in this study and that this slight ply angle misalignment can be a significant factor in out-of-plane deformation of cross-ply laminates.

Original languageEnglish
Pages (from-to)1225-1230
Number of pages6
JournalComposite Structures
Issue number4
Publication statusPublished - 2011 Mar



  • CFRP
  • Dimensional stability
  • Moisture absorption
  • Ply angle misalignment

ASJC Scopus subject areas

  • Ceramics and Composites
  • Civil and Structural Engineering

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