Master curve approach to axial stiffness calculation for non-crimp fabric biaxial composites with out-of-plane waviness

• Published in: Composites. Part B, Engineering Vol. 64; pp. 214 - 221
• Main Authors: Zrida, H., Marklund, E., Ayadi, Z., Varna, J.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-08-2014; Elsevier
• Subjects: A. Polymer–matrix composites (PMCs); A. Tow; Amplitudes; Applied sciences; B. Mechanical properties; C. Finite element analysis (FEA); C. Laminate mechanics; Curved; Engineering Sciences; Exact sciences and technology; Forms of application and semi-finished materials; Laminates; Materials; Mathematical analysis; Mathematical models; Mechanics; Mechanics of materials; Polymer industry, paints, wood; Polymera konstruktionsmaterial; Polymeric Composite Materials; Stiffness; Technology of polymers; Wavelengths; Waviness; A. Polymer–matrix composites (PMCs); A. Tow; B. Mechanical properties; C. Finite element analysis (FEA); C. Laminate mechanics; Laminate; Material defect; Fiber reinforced material; Epoxy resin; Theoretical study; Mineral fiber; Modeling; Composite material; Finite element method; A. Polymer-matrix composites (PMCs); Ripple; Numerical simulation; Stiffness; Glass fiber; Needled material; Carbon fiber; Mechanical properties; Laminate mechanics; Tow; Polymer-matrix composites (PMCs); Finite element analysis (FEA)
• ISSN: 1359-8368; 1879-1069; 1879-1069
• DOI: 10.1016/j.compositesb.2014.04.023

The effect of 0°-tow out-of-plane waviness on the biaxial non-crimp-fabric (NCF) composite axial stiffness is investigated. Homogenizing, the bundle mesostructure of the NCF composite is replaced by layers. Then the composite is represented by a laminate with flat layers with effective stiffness properties representing the curved 0°-layer and the 90°-layer with varying thickness. It is shown that the NCF composite knock-down factor characterizing the stiffness degradation has almost the same dependence on wave parameters as the knock-down factor for the curved 0°-layer. Numerical analysis showed that 90°-layer knock-down factor versus amplitude curves for different wavelength can be reduced to one master curve which can be described by a one-parameter expression with the parameter dependent on the used material. This observation is used to obtain high accuracy for analytical predictions for knock-down factors for cases with different wavelength and amplitudes based on two FE calculations only.