Pipes are used to traort oil, gas, water, sanitation and protection of telecommunication cables and transmission lines. Conventional metal pipes were replaced by fiber-reinforced composite pipes due to their disadvantages such as high weight and lack of resistance in corrosive environment. Tubular textiles can be produced using different conventional production systems such as filament winding, weaving, braiding and knitting. Weft knitting technology has a high potantial to produce the tubular and 3D complex structures. This study untertakes to investigate the mechnaical properties of the glass-epoxy composite pipe reinforced with 3D weft knitted spacer fabrics. The tubular spacer fabrics were produced on a modern flat knitting machine in a tubular form. This tubular structure consists of two independent outer and inner layers in cylindrical form that can be connected by several connecting layers. The produced knitted fabrics was utilized as reinforcement part to faricate a themoset composite using hand lay-up and vacuum infusion molding methods. Mechanical properties of the thermoset tubular composite reinforced with spacer knitted fabrics have not reported in the litrature. The tubular composites were subjeted to internal hydrostatic pressure and external static pressure. Multi-scaled finite element modeling was used to simulated the mechanical properties of the produced composite. The unit-cell of the knitted structure was created in Catia software and then fed to Abaqus software for further analysis. Engineering constants were obtained from fabric unit-cell riched by resin. Using the homogenization techniqe, the extracted engineering constants was assigned to a macro-scale model of knitted composite. The mechanical properties of composite structure were simulated in term of internal hydrostatic and external static pressures. The findings shows acceptable correlation between experimental and modeling results. Keywords: Composite pipes, External static pressure, Glass/epoxy composites, Internal hydrostatic pressure, Numerical simulation, Weft knitted spacer fabrics.
