The 12th International Conference on Hydrodynamics
18 – 23 september 2016, Egmond aan Zee, The Netherlands
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EXTREME WAVE INTERACTION ON TRUSS STRUCTURE


Go-down ichd2016 Tracking Number 115

Presentation:
Session: Fluid structural inter-actions IV
Room: Room 4
Session start: 10:30 Tue 20 Sep 2016

Sruthi Chandrasekar   sruthichandrashekar@gmail.com
Affifliation: IIT Madras

Sriram Venkatachalam   vsriram@iitm.ac.in
Affifliation: IIT Madras


Topics: - Ship hydrodynamics resistance, propulsion, powering, seakeeping, manoeuvrability, slamming, sloshing, impact, green water, - Fluid-structural interactions and hydroelasticity

Abstract:

Owing to increased support for renewable resources, offshore wind turbines have got lot of attention these days. One important installation in offshore wind turbine is the substructure which is subjected to wave loads. The truss tower has several key advantages like less weight and a more flexible design. Extreme load may result from breaking waves. The magnitude of loading will depend on the substructure type which may also be a controlling factor in design. In this study experiments were conducted on truss structure. Forces so far calculated on the whole structure is based on formulas proposed for single cylinder. Hence to have clarity, the whole truss structure was tested. Focusing waves were generated and waves are made to break at specified location. Focusing waves were chosen for breaking of waves without slope. The focusing point was changed so that the waves break in-front of the structure, on the front leg, between the braces, on the rear leg which will form different loading cases. In order to understand the braced effects, the structure was dismantled and tested. Two legs with braces in the direction of wave and another setup with braces transverse to wave direction were installed. The same loading cases was executed for the above mentioned experimental setup. Load transducers were used to measure the response of the structure. Further the results were analyzed using Duhamel integral and the impact force estimated. The main aim of study is to understand the time variation of load and the time for which load acts. Comparison with existing theoretical formulas proposed for slamming load on cylinder proposed by Goda, et al. (1966), Wienke and Oumeraci (2005) were also done.