ON THE STRUCTURE AND PROPERTIES OF THREE-DIMENSIONAL BRAID REINFORCED COMPOSITES

• Main Author: WHYTE, DENNIS WINSTON
• Format: Dissertation
• Language: English
• Subjects: engineering, materials science

The development of 3-D braid reinforced composites is gaining increasing importance for use in engineering structural applications. In this study, a design methodology has been developed for the design, manufacture and analysis of the 3-D braid reinforced composite. Incorporated in this design methodology is the processing science base relating the fiber architecture, fiber material properties, fiber volume fraction, and the composite geometry to the structural characteristics of the braiding machine.
To provide a link between the processing science base and the mechanical behavior of the composite, a mathematical model has been developed. The model is referred to as the "Fabric Geometry Model" and is based on a combination of structural textile mechanics, a 3-D laminate theory type of analogy and numerical techniques. Loading of the composite is simulated by an incremental strain method and failure is determined by a maximum strain energy criterion. Excellent correlation between predicted values and experimental test values have been observed for tensile, compressive and shear stress states. The procedure can be applied to 3-D braid reinforced ceramic, metallic or resin matrix composite systems under tensile, compressive, shear and bending stress states.