The development of spread-tow thin-ply technology and automated fiber placement has allowed for improved freedom concerning the design of composite laminates. This allows the previously inapplicable innovative stacking sequence to be applied to structural components. A disadvantage to this application is that numerous candidate stacking patterns must be reviewed in the design process. Furthermore, it was reported that the superior transverse strength and longitudinal shear strength of thin-ply CFRP do not always positively affect the notched laminate strength. To optimize the future design of CFRP laminated structures by tailoring the ply thickness and orientation, this study develops a nonlinear extended finite element method (XFEM) that considers both geometric and material nonlinearity, including plasticity, damage, and non-Hookean behavior. Using the developed scheme, the open-hole tensile strength of the CFRP laminates is evaluated in cases concerning various ply thicknesses and layups; the effects of nonlinearity on the laminate strength are subsequently examined.
