An experimental and computational investigation of embedded wrinkle's impacts on the compressive responses of thick unidirectional glass fiber-reinforced composites

In thick unidirectional glass fiber-reinforced composites, the out-of-plane embedded wrinkle flaws have a major impact on compressive failure, which should be taken into account and assessed during the design, manufacturing, and inspection phases. The thick unidirectional coupons with embedded wrinkles of various severities were manufactured and tested. The deformation of the wrinkle region was captured by the Digital Image Correlation (DIC). As the wrinkle angle increased, the compressive failure stress decreases and the modulus does not change significantly, while the wrinkle amplitude has a negative effect on both the compressive failure stress and elastic modulus. The linear texture image regression approach is used to account for the path of fibers. The high-fidelity three-dimensional finite element (FE) models considering the real paths of the fibers are established. To reveal the interplay and impact of wrinkle severity parameters on the compressive failure behavior of composites, the progressive damage analyses and cohesive elements are also incorporated. Compared with the experiments, the FE studies accurately identify the dominant failure modes and failure stress values for various wrinkle severity parameters.