Progressive Damage and Failure Responses of Hybrid 3D Textile Composites Subjected to Dynamic Flexural Loading

Abstract

The dynamic flexural response of a hybrid 3D textile composites (H3DTC) was examined through a three-point bend test. The H3DTC contains three different types of constituent fibers, including carbon, glass, and Kevlar that are integrally woven into a single preform. Tests were carried out using a drop tower facility, which can provide different impact velocities by varying the height of the weight that is dropped onto the specimen. High-speed cameras were utilized to record the deformation history and identify the modes of failure. The experimental results show that the development of kink bands in the tows undergoing compressive straining, limits the strength of the H3DTC in flexure, while the final catastrophic failure is due to tow rupture occurring in regions subjected to tensile straining. A global-local multiscale finite element (FE) model was developed to predict the progressive damage and failure response of the H3DTC subjected to low velocity impact. The composite was homogenized as an orthotropic solid at the macroscale, while the damage and failure was incorporated through a mesoscale FE model, which is a collection of repeat unit cells (RUCs) that are composed of fiber tows embedded in a surrounding matrix. A novel micromechanics model was implemented at the fiber-matrix level to compute the fiber tow constitutive responses at the mesoscale. The smeared crack approach (SCA) was employed to model the observed failure modes, including matrix cracking, tow kinking, and tow rupture. The computational results agree well with the experiment. Therefore, the proposed multiscale model can be used as a validated computational tool to understand the effect of textile architecture and constituent properties on the progressive damage and failure responses of 3D textile composites.