Modelling and Analysis of Dynamic Stability of Glass Reinforced Plastic Pipes Subjected to Fluid Flow

Abstract

In the past, almost every industry worldwide patronized iron and its alloys for every major industrial design, construction and other forms of work. However, with the advent of the Glass Reinforced Plastic (GRP) as accepted in the United Kingdom or the Fibre Reinforced Plastic as accepted in the United States, which was discovered in the nineteen thirty’s (1930’s), the Glass Reinforced Plastic (GRP) has become very versatile as it has become a household name in most industries globally .It has attained this height through the significant properties it possesses, which include its ability to transform into moulds of difficult and delicate shapes and sizes which iron and its alloy may not find easy to submit to. It brings a host of other benefits in the form of long term performance and reliability, ease of installation and the ability to withstand corrosion and tuberculation. A service life of more than thrice that of the ductile iron pipes to mention but a few. Ductile Iron pipes are used in most petrochemical industries where pipeline plays a very important role in transporting crude oil and gas. As the service duration increases, the pipe lines are affected by corrosion mechanism which can lead to fatal accident. Corrosion can occur at both the internal and external surface of the pipelines. In general, corrosion would cause metal loss which leads to reduction in pipeline thickness and consequently reduce its strength. It becomes necessary that the stability of the Glass Reinforced Plastic (GRP) pipes are carefully investigated especially in the event of high pressure turbulent flows. This is the thrust of this work. In the light of the above, ductile iron pipes and Glass Reinforced Plastics (GRP) pipes of the same thicknesses were investigated, some special characteristics such as the bursting pressures were calculated using Peter Barlow’s formula. The ANSYS software was also used for modal analysis and compare the stress profile under dynamic condition for both pipes. Also the cost of production of pipes, classification and the difficulties encountered during their installation processes were examined. The result indicated an overwhelming encouragement to use Glass Reinforced Plastic (GRP) pipes as substitutes to the traditional ductile iron and its alloys in view of the fact that Glass Reinforced Plastic (GRP) pipes withstand corrosion and tuberculation while saving the huge cost that would have been used for pigging