Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

Research on the articulated connector load response of serially connected multi-module platformYu-chao Chen1,2, Qi-bin Wang1,2, Xin-yun Ni1,2, Ye Lu1,2, Zhen Lu1,2, Xiao-ming Cheng1,2
1 China Ship Scientific Research Center, Wuxi, China
2 Taihu Laboratory of Deepsea Technological Science, Wuxi, China

the rigid body calculation model and the elastic calculation model. The
rigid body assumption ignores the structure stiffness and the rigid bodymodules are connected by consolidation or hinge constraints according
to the connector type. After calculating the load on the connection
section, the load distribution is carried out according to the arrangementof connector, and the load of a single connector is obtained.
The elastic calculation model takes elastic deformation into account.
After the complete structure model of the platform is established, themodules are connected by 6-DOF springs to simulate the stiffness
characteristics of the connector. The modal information of the multimodule platform and the connector load in specified mode are obtained
through hydroelastic analysis, after load RAO of each connector is
calculated, the extreme load is obtained through short-term prediction.
In this article, a three-module serially connected platform is taken as
the research object, and the rigid body calculation model and the elastic
calculation model are used to analyze the load of the connector. The
extreme load of the connector under the design condition is calculated,
and the results are compared and analyzed.

ABSTRACTThe articulated connector is suitable for serially connected multimodule platform, which can reduce the section load by releasing
relative pitch. The connector is an important part of the multi-module
platform system, and its load response will directly affect the safety ofthe platform. In this paper, a three-module serially connected platform
is taken as the research object, the rigid body calculation model and theelastic calculation model are used to analyze the load of the connector.
The rigid body assumption ignores the stiffness of the connector andthe platform. After calculating the load on the connection section, loaddistribution is performed in combination with the layout of theconnector. Then the force of each single connector is obtained. The
elastic model assumption considers the elastic deformation of theplatform and the connector. After the complete structure model of theplatform is established, the stiffness characteristics of each connector
are simulated through the elastic connection elements. After obtaining
the load RAO of each connector by the hydroelastic analysis method,the extreme load of each connector is obtained through short-termprediction. In this paper, after calculating the extreme load of theconnector under the design conditions, the results obtained by the twomethods are compared, and the reasons for the difference between them
are analyzed. Based on these results, this article also discusses theapplicability of the two methods at various stages of connector design.
KEY WORDS: Articulated connector; serially connected multimodule platform; load response; rigid body assumption; elastic modelassumption; hydroelastic analysis method

THEORETICAL BACKGROUD
Introduction of Three-dimensional Hydroelastic Theory
Assuming that the fluid is inviscid, non-rotating, incompressible anduniform, and the free surface wave is micro-amplitude wave. The fluid
motion can be described by the three-dimensional potential flow theory
in the Euler coordinate system. Combined with structural dynamics, thegeneralized three-dimensional linear frequency-domain hydroelastic
motion equation of the floating body is as follows (Wu, 1984):

INTRODUCTION(1)

Very large floating structures are usually divided into several basicmodules, which are combined by connectors to reduce the load of thestructure. It was noted (Miao et al., 2018; Ding et al., 2020) that thearticulated connector is a suitable type for serially connected multimodule platform, which can reduce the section load by releasing therelative pitch. As an important part of the multi-module platformsystem, the load response of the connector directly affects the safety ofthe platform.
The connector load response analysis usually adopts two forms (Riggset al., 2000; Li et al., 2017; Li et al., 2018; Yang et al. 2019), namely

Where [a] is generalized structural mass matrix, [b] is generalized
structural damping matrix, and [c] is generalized structural stiffness
matrix. [A] is generalized fluid additional mass matrix, [B] isgeneralized fluid additional damping matrix, and [C] is generalized
fluid restoring force matrix. {Z} is generalized surface distribution
force, {Δ} is Generalized concentrated force, and {Q} is generalized
body force array. {p} is generalized principal coordinate vector. The
expressions for each element in the fluid-added mass matrix, fluid-792