On the scale and elasticity effects in dynamic analysis of mooring lines
Abstract
Due to the complexity of hydrodynamics aspects of offshore structures behaviour, experimental tests are practically compulsory in order to be able to properly evaluate and then to validate their behaviour in real sea. Moreover, the necessity to carry out hydrodynamic tests is often required by customers, classification societies and other regulatory bodies. Consequently, the correct simulation of physical properties of the complex scaled models becomes a very important issue which, sometime, is not correctly understood and applied. The present paper is trying to evaluate such kinds of problems which could arise based on some systematic tests on the dynamic behaviour of a mooring chain reproduced at five different scales. Dynamic effects as well as the influences of the elasticity simulation for 5 different scales are evaluated together. It is pointed out the necessity to pay a deeper attention to the simulation of the elasticity of coupling elements in order to ensure an acceptable level of accuracy of the experimental results. It is concluded that a much deeper investigation has to be performed.
References
[2]. Chakrabarti, S., “Physical Model Testing of Floating Offshore Structures”, Dynamic Positioning Conference, Huston, USA, 1998.
[3]. Crudu, L., Obreja, D.C., Stoicescu, L.,“Experimental Research on the Dynamic Behaviour of Mooring Lines”, 16th International Conference on Offshore Mechanics and Arctic Engineering, ASME PAPER No. OMAE-97-1800, Yokohama, Japan, 1997.
[4]. Crudu, L., “Theoretical and experimental contributions on the hydrodynamics of moored offshore structures for oil exploitation”, Ph. D. Thesis (in Romanian), University of Galati, Romania, July, 2008.
[5]. Crudu, L., “Experimental investigation of mooring parameters on surge motions of a semisubmersible on longitudinal waves”, The Annals of the „Dunarea de Jos” University of Galati, Fascicle XI – Shipbuilding, 2012.
[6]. Emori, R.I., Schuring, D.J., “Scale Models in Engineering. Fundamentals and Applications”, Pergamon Press, 1977.
[7]. Kinoshita, T., Hirata, K., Colbourne, B., Pinkster, J.A., Jianmin, Y., Ha, M.K., Thiagarajan, K., Crudu, L., “Report of the ITTC Specialist Committee on Stationary Floating Systems”, 23rd International Towing Tank Conference (ITTC), Volume II, pp. 545-571, 8–14 September, Venice, Italy, 2002 and Marine Technology, Holland, 2002.
[8]. Matulea, I., Popa, V., Strat, I., Rusu, E., Talmaciu, N., Crudu, L., “Mecanica firelor aplicată în tehnologia marină”, Mecanica, Metode numerice, vol. I, Universitatea din Galaţi, 1988.
[9]. Nakajima, S., Motora, S., Fujimo, M., “On the Dynamic Analysis of Multi-Component Mooring Lines”, 14th OTC, paper no. 4309, Houston, Texas, May 1982
[10]. Remery, G.F.M., “Model Testing for the Design of Offshore Structures”, Symposium on Offshore Hydrodynamics, Publication no. 375, NSMB, Wageningen, August 1971.
[11]. van Sluijs, M.F., Blok, J.J., “The Dynamic Behaviour of Mooring Lines”, Offshore Technology Conference, Paper No. 2881, Houston, 1977.
