Optimization Design Method of the Umbilical Cable Global Configuration Based on Representative Fatigue Conditions

Abstract

Umbilical cable is one of the key equipment for deep sea oil and gas exploration. To ensure structural safety and normal functioning, the umbilical cable is often presented with a specific global configuration for compensating for the floating body motion due to the harsh environmental load during operation. Considering the reciprocating periodicity of the dynamic response of the umbilical cable under ocean wave loads, the fatigue analysis is required to ensure the safe operation. However, the numerous sea conditions lead to a huge amount of calculation. Aiming at the global configuration design of the lazy-wave umbilical cable, this study carried out a global configuration optimization design method based on a few representative fatigue conditions. The design variables were the control parameters of the global configuration, and the total length and the cumulative fatigue damage were the two objective functions. By resolving the optimization formulation, an optimal global configuration design for a dynamic umbilical cable with antifatigue performance and economic cost was obtained.