MECHANICAL CHARACTERIZATION OF TRIAXIALLY BRAIDED HYBRID COMPOSITES

The use of advanced composites has been expanded to the oil and gas in dustry. One of the newly developed technologies is in composite coiled tubing that offers the potential of exceeding the performance of meta llic tubings. The high strains due to bending and the complex state of stress in these tubes necessitate the better understanding of the cor relation between fiber architecture and tube performance. Braided comp osites can withstand high bending deformation without severe degradati on of properties. In this study, braided hybrid composites are present ed as an option for achieving high performance coiled tubing under ten sile and flexural loads. The effects of material and fabric microstruc tural parameters on the mechanical behavior of braided hybrid composit es are studied. The mechanical characterization of triaxially braided composites has identified the influence of the mechanical properties o f the axial yam, the axial yam volume fraction, and the braid angle. O verall, this study provides a sound knowledge base for the design, fab rication, and characterization of triaxially braided composites for co iled tubing applications in the petroleum industry.