液压式张紧器对顶张力立管静动力响应的影响

Influence of Hydro-Pneumatic Tensioner on Static and Dynamic Response of Top Tensioned Riser

为准确了解张紧器对立管静动力响应的影响以及处理传统分析时立管顶部简化处理的问题,本文充分考虑张紧器的作用,基于向量式有限元(VFIFE)法建立立管动力学模型,研究张紧器对立管静动力响应的影响以及对平台运动传递的规律。研究结果表明:本文建立的立管动力学分析模型能够有效考虑张紧器的影响;海流作用下立管的静力分析中,张紧器能提供更大的顶张力,从而减小立管的横向位移以及最大弯矩;波浪以及平台作用下的动态分析中,张紧器对平台纵荡的传递影响较小,对垂荡的补偿效应明显,补偿后的立管顶端位移远远小于平台运动幅值,并且在张紧器对顶部平台运动的缓冲作用下立管的位移和弯矩受平台运动影响不大。因此在分析中考虑张紧器对平台运动的传递补偿作用能更准确合理地施加顶张力以及平台运动,从而能更加有效的预测立管的响应。

In order to accurately understand the influence of the tensioner on the static and dynamic response of the riser and deal with the simplified treatment of the top of riser in the traditional analysis,this paper fully considers the role of the tensioner,establishes the riser dynamic model based on the vector form intrinsic finite element(VFIFE)method,and studies the influence of the tensioner on the static and dynamic response of the riser and the rules of motion transmission of the platform.The results show that the riser dynamic analysis model established in this paper can effectively consider the influence of tensioner.In the static analysis of riser under ocean current,the tensioner can provide greater top tension,so as to reduce the lateral displacement and maximum bending moment of riser.In the dynamic analysis under the action of wave and platform,the tensioner has little influence on the transmission of platform surge motion,and the compensation effect on heave motion is obvious.The vertical displacement at the top of the riser after compensation is far less than the platform motion amplitude,and the displacement and bending moment of the riser are not affected by the platform motion because of the tensioner.Therefore,considering the role of tensioner in the analysis can more accurately and reasonably apply top tension and platform motion,so as to more effectively predict the response of riser.