The coupling effect of current, wave and platform movement on the dynamic characteristics of marine risers with different elastic modulus and constraint number

Abstract

An experimental study was conducted to investigate the dynamic response of production risers under the coupling effect of current, wave and platform movement. Seven experimental parameters were considered, i.e., elastic modulus, constraint number, flow velocity, wave height, wave period, static movement of platform and dynamic movement of platform. Based on these parameters, 32 test conditions were designed and conducted. By employing a multiple nonlinear regression model and biased estimation regression method, the influence of coupling effect and the impact of various parameters on the dynamic response of the risers were obtained. The results showed that increasing the number of coupled parameters enhanced the model’s reliability; and when three parameters were coupled, an acceptable accuracy could be achieved. It’s also found that the sequence of importance for the vibration of the riser in the in-flow direction was: static displacement > elastic modulus > constraint number > wave period > wave height > flow velocity > dynamic displacement; while in the cross-flow direction was: elastic modulus > flow velocity > static displacement > wave period > wave height > constraint number > dynamic displacement.