This book contains some new developments in the area of Structural Dynamics. In general it reflects the recent efforts of several Austrian research groups during the years 1985 - 1990. The contents of this book cover both theoretical developments as well as practical applications and hence can be utilized by researchers as well as the practicing engineers. Quite naturally, realistic modeling of a number of load types such as wind and earthquake loading, etc. , requires taking into account statistical uncertainties. Hence these loads have to be characterized by stochastic processes. As a consequence, stochastic aspects must play a major role in modem structural dynamics. Since an extended modeling of the load processes should not be counterbalanced by simplifying the structural models, considerable efforts have been put into the development of procedures which allow the utilization of e. g. FE models and codes which are utilized presently in context with simplified, i. e. deterministic load models. Thus the processing of the additional information on loads as well as including statistical properties of the material allows to provide additional answers, i. e. quantification of the risk of structural failure. This volume concentrates on four major areas, i. e. on load modeling, structural response analysis, computational reliability procedures, and finally on practical application. Quite naturally only special fields and particular, i. e. selected types of problems can be covered. Specific reference is made, however, to cases where generalizations are possible.