Evaluation of optimisation techniques in the design of composite pipelines

The optimisation of design parameters associated with glass-reinforced epoxy pipelines for use in gas distribution networks is investigated. Maximum operating pressures are set at 70 bar with a factor of safety on burst pressures of 4.5. The optimisation procedures are extensively automated whereby iterative finite element solutions are executed under the control of a software suite containing information on the optimisation parameters, objective functions and constraints. As no optimisation algorithm is suitable for all parameters a variety of mathematical techniques are available, and these are extensively evaluated with respect to the design of a composite pipeline. The major parameters investigated are pipeline layer thicknesses and winding angles. Four optimisation procedures are extensively tested and evaluated and particular problems with parameters such as winding angles are exposed. Recommendations on preferred approaches to the application of optimisation techniques in the design of composite pipelines are advanced.