Strength prediction of ply waviness in composite materials considering matrix dominated effects

Ply waviness (PW) is a commonly observed manufacturing defect in composite materials leading to degradation of the mechanical properties. The effects of matrix systems on the strength behavior of unidirectional laminates containing ply wavinesses are analyzed for compressive loading. An analytical approach based on Hsiao and Daniel (1996) allows an estimation of stiffness and strength in dependence on waveform and material. While the geometry of the waviness can be characterized by its amplitude to wavelength ratio and its wave shape (uniform or graded), composite constituents can be considered individually. The approach according to Hsiao and Daniel is enhanced by the Puck failure criterion Schürmann (2005) and is implemented as a graphical user interface (gui) using the software matlab. The analytical approach is validated against literature data. Strength properties are individually varied, indicating that failure behavior of wavy laminates is mostly affected by matrix dominated shear strength R12R12.