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

• Published in: Composite structures 2011-03, Vol.93 (4), p.1225-1230
• Main Authors: Arao, Yoshihiko, Koyanagi, Jun, Utsunomiya, Shin, Kawada, Hiroyuki
• Format: Article
• Language: English
• Subjects: Alignment; Applied sciences; Carbon fiber reinforced plastics; CFRP; Composite structures; Composites; Computer simulation; Deformation; Dimensional stability; Exact sciences and technology; Forms of application and semi-finished materials; Fundamental areas of phenomenology (including applications); Laminates; Misalignment; Moisture absorption; Monte Carlo methods; Physics; Ply angle misalignment; Polymer industry, paints, wood; Solid mechanics; Static elasticity (thermoelasticity...); Structural and continuum mechanics; Technology of polymers
• ISSN: 0263-8223; 1879-1085
• DOI: 10.1016/j.compstruct.2010.10.019

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.