Nonlinear Deformation Behavior of New Braided Composites with Six-axis Yarn Orientations

Abstract

The braiding technology is one of fabrication methods that can produce three‐dimensional fiber preforms. Braided composites have many advantages over other two‐dimensional composites such as no delamination, high impact and fatigue properties, near‐net shape preform, etc. Due to the undulated yarns in the braided preforms, however, their axial stiffness is lower than that of uni‐directional or woven composites. To improve the axial stiffness, the longitudinal axial yarns were already introduced along with the braiding axis (five‐axis braiding technology). In this study, we developed a new braided structure using six‐axis braiding technology. In addition to braiding and longitudinal axial yarns, transverse axial yarn was introduced. New braided composites, so called six‐axis braiding composites, were manufactured using ultra high molecular weight polyethylene and epoxy resin and their mechanical properties were characterized. To investigate the mechanical performance of these braided composites according to their manufacturing conditions, a numerical analysis was performed using their unit‐cell modeling and finite element analysis. In the analysis the nonlinear deformation behavior will be included.