Abstract: The steel lazy wave catenary riser has many design parameters, which is cheerful due to its cheap price, and it is necessary to find the optimal design configuration with minimum stress among various parameters. The riser configuration influences of the horizontal span, suspension length, float length and float diameter are discussed at first. The full factorial design of experiment is used to determine the sample points, and then the static stress response surface model of a lazy wave steel catenary riser is established by using the catenary theory. Finally, the multi-objective particle swarm optimization algorithm is used to solve the pareto optimal solution set, which can be chosen for the optimal riser design in engineering. Comparing with single optimization object, the multi-objective particle swarm optimization algorithm can effectively deal with the minimization optimization for both the hang-off point and the touch-down zone of the riser, and the optimization results show that the force of the riser in the optimal scheme is significantly reduced at hang-off point and touch-down point.

Key words: Steel lazy wave catenary risers, Response surface model, Multiple objective, Particle swarm optimization