This textbook provides the material for both basic and intermediate moderncourses in dynamic analysis of ships and offshore structures. The word“modern” is used to signify that both deterministic and stochasticdynamics are covered. Because the main goal is to provide an introduction todynamic analysis, the basic elements are described in some detail. A consequenceof this is that the majority of the book deals with structures or structuralelements that can be modeled or reduced to a single-degree-of-freedom (SDOF)system. However, realizing that multi-degree-of-freedom (MDOF) systems areunavoidable in many practical situations the engineer is likely to meet, and,consequently, that the basic principles for their analysis should be understood,a chapter on linear MDOF systems is included. This is also done to clearlydemonstrate the principle of modal decomposition whereby an MDOF system isreduced to a set of uncoupled SDOF systems.

Broadly speaking, a dynamic analysis is carried out in two different waysaccording to how the loading is specified. If the time-variant loading is givenin such a way that we may consider it to be exactly known as a function of time,the same will apply to the response. In such a case, the dynamic analysis iscalled deterministic. This is in contrast to a stochastic analysis, where theloading is specified using probabilistic concepts. This implies that thecorresponding displacements and tensions can only be described in the sameway.