Abstract: Traditional steel pipes applied to as submarine pipelines and risers in the deep oil exploitation have defects of poor corrosion resistance, large weight and weak flexibility. The thermoplastic glass fiber reinforced flexible pipes with features of high corrosion resistance, light weight and high strength and good flexibility are becoming the trend of marine pipelines development. Aiming at designing cross section structure of reinforcement layer of glass fiber reinforced flexible pipes, which are utilized to oil well in 500 m deep sea, according to DNVGL-RP-F119 specification and ABS relevant regulation, combination models of ±30°~±75°winding angle and 20~40 winding layers are set by experience, in response to the problem of winding angle and winding layers in reinforcement layer. ABAQUS finite element analysis software is employed to make strength analysis under three load cases in which the inner pressure is 30 MPa, tensile load is 60 t, external pressure is 5 MPa. Optimal winding angle ±60° is obtained which is satisfied with above three kinds of load cases. Moreover, after strength check of 90 MPa burst pressure and combined load case of tensile load and external pressure , it reveals that the reinforcement structure in which the optimal winding angle is ±60°and minimum winding layers are 36 can meet the requirement of technical indicators.

Key words: deep sea, glass fiber reinforced flexible pipe, cross structure design, finite element, winding angle, winding layer