This monograph provides a general background to the modelling of a special class of offshore structures known as compliant structures. External forcing is resisted by buoyancy and tension forces which increase when the structure is slightly offset from its equilibrium. The technical development given in this book is presented in such a way as to highlight the adaptability of the modelling, and the reader is shown how the techniques described can be applied to a variety of different offshore structures.

The purpose of this monograph is to show how a compliant offshore structure in an ocean environment can be modeled in two and three di mensions. The monograph is divided into five parts. Chapter 1 provides the engineering motivation for this work, that is, offshore structures. These are very complex structures used for a variety of applications. It is possible to use beam models to initially study their dynamics. Chapter 2 is a review of variational methods, and thus includes the topics: princi ple of virtual work, D'Alembert's principle, Lagrange's equation, Hamil ton's principle, and the extended Hamilton's principle. These methods are used to derive the equations of motion throughout this monograph. Chapter 3 is a review of existing transverse beam models. They are the Euler-Bernoulli, Rayleigh, shear and Timoshenko models. The equa tions of motion are derived and solved analytically using the extended Hamilton's principle, as outlined in Chapter 2. For engineering purposes, the natural frequencies of the beam models are presented graphically as functions of normalized wave number and geometrical and physical pa rameters. Beam models are useful as representations of complex struc tures. In Chapter 4, a fluid force that is representative of those that act on offshore structures is formulated. The environmental load due to ocean current and random waves is obtained using Morison's equa tion. The random waves are formulated using the Pierson-Moskowitz spectrum with the Airy linear wave theory.

This monograph provides a general background to the modelling of a special class of offshore structures known as compliant structures. External forcing is resisted by buoyancy and tension forces which increase when the structure is slightly offset from its equilibrium. The technical development given in this book is presented in such a way as to highlight the adaptability of the modelling, and the reader is shown how the techniques described can be applied to a variety of different offshore structures.

This report presents reliable techniques for modeling extremely compliant structures. The research focuses on severe geometric nonlinearities associated with very large displacements and rotations. The solution requires two major modeling improvements: formulation of well-conditioned finite elements and development of specific control strategies for nonlinear step-by-step solution. Inherent in the physics of the structure, natural events condition the new finite elements. Associated event control directs the numerical solution to adhere closely to the true nonlinear structural response path. The numerical strategies are a simple extension of the trapezoidal rule for time integration and Newton iteration for nonlinear step-by-step solution. The result is extremely fast, efficient, and stable nonlinear structural simulation. A high level of computational robustness is essential for development of fully nonlinear substructured models. A local/global approach allows each substructure to have its own specialized local submodel and its own associated local solution strategy. A global model then integrates all the super-element representations of each diverse submodel. The local/global framework allows the nonlinear solution strategies to efficiently concentrate computational power where and when needed among the submodels. Code development and test problems focus primarily on compliant marine structures, where the need for robust, highly nonlinear simulation is so great.

Compliant Offshore Structures deals with some aspects of the mechanics of compliant offshore structures. Analysis methods for determining the hydrostatic and hydrodynamic behavior, at wave frequencies only, of conventional and novel compliant structure types are described. The contribution of hull configuration for tandem hull vessels and of pneumatic compliances for ship shape and semi-submersible vessels is also emphasized. Comprised of 11 chapters, this book begins with an overview of the various conventional and emerging methods of hydrostatic and hydrodynamic analysis that are available for characterizing compliant marine structures. The response of compliant structures to ocean waves is given emphasis, along with the hydrostatic stability of a compliant vessel. The discussion then turns to the use of analysis methods for a variety of conventional and novel compliant structures such as semi-submersibles, ship forms, tensioned buoyant platforms, crane vessels, and vertical marine risers. However, those compliant structures that are believed to have a future application or, alternatively, are useful in illustrating an interesting performance feature are also considered. Among such structures are those with articulated joints, pneumatic compliances, and tandem hull marine vehicles. This monograph is intended for practicing engineers as well as undergraduate and postgraduate students.

This monograph provides a general background to the modelling of a special class of offshore structures known as compliant structures. External forcing is resisted by buoyancy and tension forces which increase when the structure is slightly offset from its equilibrium. The technical development given in this book is presented in such a way as to highlight the adaptability of the modelling, and the reader is shown how the techniques described can be applied to a variety of different offshore structures.

For students and professionals, this covers theory and methods for stochastic modelling and analysis of marine structures under environmental loads.

This book comprises the proceedings of the Fifth International Conference in Ocean Engineering (ICOE2019) focusing on emerging opportunities and challenges in the field of ocean engineering and offshore structures. Some of the themes covered in this volume are offshore structures and deepwater technology, ocean optics & acoustics, ocean renewable energy, marine spatial planning, climate change impacts & disaster risk reduction, etc. The essays are written by leading international experts, making it a valuable resource for researchers and practicing engineers alike.

This is the first book which exploits concepts and tools of global nonlinear dynamics for bridging the gap between theoretical and practical stability of systems/structures, and for possibly enhancing the engineering design in macro-, micro- and nano-mechanics. Addressed topics include complementing theoretical and practical stability to achieve load carrying capacity; dynamical integrity for analyzing global dynamics, for interpreting/predicting experimental behavior, for getting hints towards engineering design; techniques for control of chaos; response of uncontrolled and controlled system/models in applied mechanics and structural dynamics by also considerung the effect of system imperfections; from relatively simple systems to multidimensional models representative of real world applications; potential and expected impact of global dynamics for engineering design.

This plenary paper and the accompanying presentation have highlighted field problems involving fluid-structure interaction over a wide span of Navy operations. Considering the vast size and versatility of the Navy's inventory, the cases presented represent examples of a much larger problem. But even this limited set provides sufficient evidence that fluid-structure interaction does hinder the Navy's ability to accomplish its missions. This survey has also established that there are no accurate and generally applicable design tools for addressing these problems. In the majority of cases the state-of-practice is to either make ad-hoc adjustments and estimates based on historical evidence, or conduct expensive focused tests directed at each specific problem and/or candidate solution. Unfortunately, these approaches do not provide insight into the fundamental problem, and neither can be considered reliable regarding their likelihood of success. So the opportunities for applying computational fluid-structure interaction modeling to Navy problems appear limitless. Scenarios range from the "simple" resonant strumming of underwater and in-air cables, to the "self-contained" flow field and vibration of aircraft/ordnance bodies at various Mach numbers, to violent underwater transient detonations and local hull structural collapse. Generally applicable and computationally tractable design-oriented models for these phenomena are of course still far in the future. But the Navy has taken the first steps in that direction by sponsoring specialized numerical models, validation experiments tailored for specific applications, and conferences such as this one.