DESIGN AND DEVELOPMENT OF AN EFFICIENT COMPUTER SIMULATION MODEL FOR RESPONSE ANALYSIS OF A MOORED SEMI-SUBMERSIBLE

This paper presents the design and development of an efficient modular ‘Computer Simulation Model (CSM)’ for response analysis of a moored semi-submersible. The computer simulation model is designed in two split models (i.e. computational and experimental models) and each of these models consists of various modules. The modules are developed from basic governing equations related to motion and modules are integrated and we aim for a seamless integration. The moored semi-submersible is represented mathematically as six degrees of freedom dynamic system and the coupling effects between the structure and mooring lines are considered. The basic geometric configuration of semi- submersible is modelled and analyzed for stability computations in MS-Excel*TM and then the basic governing equations related to motion are modelled mathematically in a module and solved numerically with Ansys-AQWA**TM. The computational model is validated and verified with some available experimental results. The CSM is utilized to study the surge and sway responses with respect to the horizontal range of mooring lines and our results show good validation with the existing experimental results. Our presented results show that the fibre wires have minimum steady state response in surge and sway degrees of freedom as compared with the steel wires. However, they have large drift as compared with steel wires. Finally, we show that the computer simulation model can help in detailed analysis of responses and results can be utilized for design and development of new age semi-submersibles for optimum performances for a given set of parameters.

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Design and Development of an Efficient Computer Simulation Model for Response Analysis of a Moored Semi-Submersible

10.3940/rina.ijme.2019.a1.503 ◽

2019 ◽

Vol 161 (A1) ◽

Keyword(s):

Computer Simulation ◽

Simulation Model ◽

Degrees Of Freedom ◽

Experimental Results ◽

Response Analysis ◽

Computer Simulation Model ◽

Governing Equations ◽

Design And Development ◽

Mooring Lines ◽

Steel Wires

This paper presents the design and development of an efficient modular ‘Computer Simulation Model (CSM)’ for response analysis of a moored semi-submersible. The computer simulation model is designed in two split models (i.e. computational and experimental models) and each of these models consists of various modules. The modules are developed from basic governing equations related to motion and modules are integrated and we aim for a seamless integration. The moored semi-submersible is represented mathematically as six degrees of freedom dynamic system and the coupling effects between the structure and mooring lines are considered. The basic geometric configuration of semisubmersible is modelled and analyzed for stability computations in MS-Excel*TM and then the basic governing equations related to motion are modelled mathematically in a module and solved numerically with Ansys-AQWA**TM. The computational model is validated and verified with some available experimental results. The CSM is utilized to study the surge and sway responses with respect to the horizontal range of mooring lines and our results show good validation with the existing experimental results. Our presented results show that the fibre wires have minimum steady state response in surge and sway degrees of freedom as compared with the steel wires. However, they have large drift as compared with steel wires. Finally, we show that the computer simulation model can help in detailed analysis of responses and results can be utilized for design and development of new age semi-submersibles for optimum performances for a given set of parameters.

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Design of Computer Simulation Model for the Analysis 0f Coupling Effects between Actuators of Hydraulically Driven 6 DOF Parallel Manipulators

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.346.184 ◽

2011 ◽

Vol 346 ◽

pp. 184-189

Author(s):

Peter O. Ogbobe ◽

Zheng Mao Ye ◽

Hong Zhou Jiang ◽

Chi Fu Yang ◽

Jun Wei Han

Keyword(s):

Computer Simulation ◽

Simulation Model ◽

Natural Frequency ◽

Degrees Of Freedom ◽

Coupling Effect ◽

Mass Matrix ◽

Parallel Manipulators ◽

Computer Simulation Model ◽

Coupling Effects ◽

Coupling Property

This paper presents a computer simulation model to analyze coupling effects between actuators of a hydraulically driven six degrees of freedom parallel manipulators. The design is based on the multi-body dynamics model of the system built using Kane’s formulation and hydromechanics’ principles. Combining the two parts, an integrated computer simulation model is designed to analyze coupling effects using joint space inverse mass matrix. The designed computer simulation model was used to establish a coupling effects relationship between actuators. The simulation results in frequency domain show that the coupling effect is heavier between odd and even numbered actuators. The result further reveal that the dynamics coupling property of the system increase with the frequency and reach the maximum value at the natural frequency. At a frequency higher than the natural frequency the coupling property decreases. This study can assist to provide optimum methods for mechanism designers and can offer a basis for comparing and selection of design options. It can also lay a good foundation for studies on decoupling control strategies.

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