Abstract
Owing to the growth in human population, the land-scarce island countries and countries with long coastline are expanding their horizon to ocean environment through very large floating structures (VLFS) for different purposes as these are cost-effective, environment-friendly and can be manufactured easily. VLFS applications include floating airports, artificial islands, mobile offshore base and Mega-Float and are built using Pontoon-type or semi-submersible-type structures. In these types of structures, because of its large size, elastic deformations are more important than their rigid body motions. In this paper, hydroelastic behaviour of a barge Pontoon-type VLFS under various water depths is investigated. Analysis is based on three-dimensional linear hydroelastic theory to obtain the wave-induced hydroelastic response of the structures in the frequency domain. For solving this coupled fluid-structure interaction problem, the modal expansion method and the dry normal modes of vibration is commonly used for the floating structure. The structure is modelled using PATRAN [1], and the hydroelastic analysis is carried using HYDRAN-XR software. Responses in regular wave in the vertical mode at salient point along the length of the VLFS are presented for various wave headings and frequency. Vertical displacements at both edges of the structures and at the centre portion are found. Response for the six water depth conditions has been examined, and the observed results emphasize that vertical displacements are dominant in deep water conditions in relative to the shallow water conditions. Results also suggest that horizontal displacement is significantly higher in shallow water conditions.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
MSC (2012) Patran reference manual [online]
Aoki SI (1997) Shallow water effect on hydrodynamic coefficients of very large floating structures. In: The seventh international offshore and polar engineering conference, Jan. International Society of Offshore and Polar Engineers
Athanassoulis GA, Belibassakis KA (1999) A consistent coupled-mode theory for the propagation of small-amplitude water waves over variable bathymetry regions. J Fluid Mech 389:275–301
Athanassoulis GA, Belibassakis KA (1998) Water-wave Green’s function for a 3D uneven-bottom problem with different depths at x→+∞ and x→−∞. In: IUTAM symposium on computational methods for unbounded domains. Springer, Netherlands, pp 21–32
Ertekin RC, Kim JW (1999) Hydroelastic response of a floating mat-type structure in oblique, shallow-water waves. J Ship Res 43(4):241–254
Tkacheva LA (2000) Eigenvibrations of a flexible platform floating on shallow water. J Appl Mech Tech Phys 41(1):159–166
Zilman G, Miloh T (2000) Hydroelastic buoyant circular plate in shallow water: a closed form solution. Appl Ocean Res 22(4):191–198
Hong SY, Choi YR, Hong SW (2001) Investigation of draft effects on analysis of hydroelastic responses of pontoon-type VLFS. In: The eleventh international offshore and polar engineering conference, Jan. International Society of Offshore and Polar Engineers
Wang CD, Meylan MH (2002) The linear wave response of a floating thin plate on water of variable depth. Appl Ocean Res 24(3):163–174
Meylan MH (2002) Spectral solution of time-dependent shallow water hydroelasticity. J Fluid Mech 454:387–402
Riggs HR, Niimi KM, Huang LL (2007) Two benchmark problems for three-dimensional, linear hydroelasticity. J Offshore Mech Arct Eng 129:149–157
Riggs HR, Hideyuki S, Ertekin RC, Jang WK, Iijima K (2008) Comparison of hydroelastic computer codes based on the ISSC VLFS benchmark. J Ocean Eng 35:589–597
Sturova IV (2008) Unsteady behaviour of a heterogeneous elastic beam floating on shallow water. J Appl Math Mech 72(6):704–714
Sturova IV (2008) Effect of bottom topography on the unsteady behaviour of an elastic plate floating on shallow water. J Appl Math Mech 72(4):417–426
Karperaki AE, Belibassakis KA, Papathanasiou TK (2016) Time-domain, shallow-water hydroelastic analysis of VLFS elastically connected to the seabed. Mar Struct 48:33–51
Wang Y, Wang X, Xu S, Ding A, Li J (2017) Motion response of a tension-leg-moored VLFS in shallow water. In: The 27th international ocean and polar engineering conference, July. International Society of Offshore and Polar Engineers
Riggs HR (2016) Hydrodynamic response analysis with integrated structural finite element analysis. HYDRAN-XR 16.3
Acknowledgements
The authors would like to acknowledge Prof. H. Ronald Riggs, University of Hawai’i at Manoa, for providing valuable insights into HYDRAN-XR procedure.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2019 Springer Nature Singapore Pte Ltd.
About this paper
Cite this paper
Somansundar, S., Panneer Selvam, R. (2019). Hydroelastic Responses of a Pontoon-Type VLFS in Different Water Depths. In: Murali, K., Sriram, V., Samad, A., Saha, N. (eds) Proceedings of the Fourth International Conference in Ocean Engineering (ICOE2018). Lecture Notes in Civil Engineering, vol 22. Springer, Singapore. https://doi.org/10.1007/978-981-13-3119-0_18
Download citation
DOI: https://doi.org/10.1007/978-981-13-3119-0_18
Published:
Publisher Name: Springer, Singapore
Print ISBN: 978-981-13-3118-3
Online ISBN: 978-981-13-3119-0
eBook Packages: EngineeringEngineering (R0)