Investigation On Mechanisms Of Filament-wound Fiber-reinforced Composite Flexible Pipe Under Internal Pressure

With rapid development of national economy and consumption of energy in our country, efficient supply of energy has become the key factor which restricts the sustainable and healthy progress. Exploitation in marine oil and gas field is an alternative way for energy supply in the future, and marine pipelines are important part for oil and gas field exploitation. Steel pipe is the most and extensive used pipe for marine oil and gas transportation, but its disadvantage is obvious:poor corrosion resistance; inefficient transportation and installation; high cost of maintenance. As a kind of new composite pipes, great corrosion resistance and flexibility, convenient transportation and installation of fiber reinforced composite flexible pipe has made it an excellent choice for transportation of marine oil and gas. According to the complicated structure, material and ocean environment, it’s very important to analyze the proper functioning and project for composite pipe.RTP is the pipe that consists of thermoplastic plastic as matrix and fiber-reinforced tapes, and its characteristic structure and material make its mechanism complicated. This paper analyzed the stress and burst pressure of the pipe subjected to short-term and long-term internal pressure, temperature variation around it. The main works of the paper are summarized as follows:(1) RTP and the material of it were simplified into the model consists of inner core, outer layer and reinforced layer. a plane model for the pipe was built and numerical method was used to analyze the stress, strain and burst pressure under internal pressure. At last, the results above were compared with the finite element analysis results.(2) On the basis of the previous model, the stresses, strains and burst pressure for the pipe subjected to internal pressure and thermoplastic loading with thermal variations.(3) On the basis of the previous model and the test data in existing literature, the stresses and strains of the pipe were computed by finite element method and numerical method considering the linear viscoelasticity of the high density Polyethylene. At last, the two results were compared.