Dynamics of Ocean Structures

Entire course will be taught in THREE modules

First module will focus on fundamentals of structural dynamics- types of offshore structures- FORM based design concepts for deep-water offshore platforms

Second module will focus on structural dynamics as applied to different offshore structures. A few experimental studies on scaled models will also be discussed in detail

Third module will focus on introduction to stochastic dynamics. Nonlinear dynamic analysis of offshore structures under special environmental loads like earthquake loads, springing and ringing waves etc will be discussed with detailed explanations on development of mathematical models for such analysis. Introduction to numerical analysis using software, with a help of step-by-step procedure will also be highlighted through relevant screen shots.

CONTENTS OF THE COURSE

Module1 - Fundamentals of structural dynamics

Introduction to different types of ocean structures - Development of structural forms for deep and ultra-deep waters - Environmental forces  - Structural action of ocean structures  -  Introduction to structural dynamics -  Characteristics of single degree-of-freedom model  -  Methods of writing equation of motion: comparison of methods -  Free and forced vibration of single degree-of-freedom systems -  Undamped and damped systems -  Formulation of equation of motion - Examples -  Coulomb damping -  Comparison of damped and undamped forced vibration - response build up -  Estimate of damping: Classical damping, Rayleigh and Caughey -  Damping by mode superposition  - Numerical problems in single degree-of-freedom systems - Two degrees-of-freedom systems -  Formulation of equation of motion - Eigenvalues and eigenvectors - Orthogonality of modes - Study of multi degrees-of-freedom systems - Equations of motion - Natural frequencies and mode shapes - Stodola, Rayleigh-Ritz and influence coefficient methods, Dunkerley  -  Matrix methods for dynamic analysis  -  Modal response method - Modal mass contribution - Missing mass correction, Example problems - Duhamel's integrals

Module2 - Application of structural dynamics to offshore structures

Fluid-structure interaction - Dynamic analysis of offshore jacket platforms - Dynamic analysis of articulated towers - Iterative frequency domain - Multi-legged articulated towers(MLAT) - Response control of multi-legged articulated towers using tuned mass dampers - Experimental and analytical studies on MLAT - Development of Tension Leg Platforms and geometric optimization - Dynamic analyses of TLPs - Development of Mass, stiffness and damping matrices of TLP from first principles - Dynamic analysis methodology of offshore structures under earthquake loads - TLPs under seismic excitation - Development of new generation offshore structures - Buoyant Leg Structures and offshore triceratops - Comparison of experimental, analytical and numerical studies on offshore triceratops - Dynamic analysis of compliant offshore structures under extreme waves (springing and ringing responses) - Stability analysis of offshore compliant structures - Hydrodynamic performance of perforated cylinders under regular waves - Structural health monitoring of offshore platforms using WSN (wireless sensor networking) - Retrofitting and rehabilitation of offshore structures - Dynamic analysis of large floating structures: Buoyant leg supported regasification platforms

Module 3: Introduction to stochastic dynamics

Introduction to stochastic dynamics of ocean structures - Random environmental processes - Stationary process - Response spectrum - Narrow band process - Return period - Fatigue prediction

Tutorials will be given at the end of every topic in each module for self assessment.An exam will be also conducted at the end of the course for enabling issue of certificate by IIT Madras.