Gaussian function characterization of unnotched tension behavior in a carbon/epoxy composite containing localized fiber waviness

This study presents the results of analytical and experimental efforts performed on the tension behavior of a common aerospace grade carbon fiber/epoxy material system containing out-of-plane fiber waviness. The composite material selected for this study is one designated by the Federal Aviation Administration’s Advanced General Aviation Transportation Experiments program for use in aerospace structural applications. Unidirectional and multidirectional laminates were examined with different thicknesses containing three levels of waviness. The waviness morphology considered in this study is a ‘degrading’ type waviness, where a relatively sharp wave occurs on the first ply and is completely diminished at the other laminate face. To determine analytically the tensile stiffness, a Gaussian function is introduced to characterize the waviness observed and is used in a transformation-based classical lamination theory approach. The tension failure behavior is also reported for the waviness specimens tested.