Hydro-Structural Design Aspects of Articulated Towers

[摘要] In this Thesis an investigation is presented into the performance of stand-alone articulated tower structures under different environmental loadings. An engineering approach is taken in analysing those design aspects, mainly associated with the dynamic response and structural strength of such structures. This enables the present analysis procedure to be applied to real design practice. Firstly, various aspects of the environmental conditions and the environmental loadings are reviewed. The major sources of the environmental loading include harmonic waves, low frequency wave drift, fluctuating winds and current. Secondly, the effect of the variation of those parameters defining the environmental loadings on the structural motion and internal sectional forces etc, of a monolithic single articulated tower is investigated. Conclusions are drawn regarding the selection of the values of those parameters. Thirdly, the effect of those parameters defining the geometrical dimensions of an articulated tower structure on its motion response, internal sectional forces and stability etc, is examined in detail. This is aimed at optimising the geometry of the articulated tower. Articulated tower structures of hybrid form, using lattices, are also studied in comparison with their equivalent monolithic form. Fourthly, studies were carried out on the viability of some of major assumptions made in the present work. They are associated with the non-linear interaction between an articulated tower and the environment and the rigid body mode vibration motion of the structure. Structural strength calculations for stiffened large diameter thin shell cylinders are presented, based on the DnV Rules, which are computerised. A structural weight optimisation is performed using a non-linear programming technique. This provides a useful means of assessing the structural strength for the design of articulated tower structures. Finally, model tests have been carried out and comparisons between the theoretical predictions and the model test measurements are presented.

[发布机构] University:University of Glasgow

[关键词] Naval engineering, Hydraulic engineering