Structural Dynamics

The lectures will focus on one of the most important applications of structural dynamics – earthquake engineering of structures. The intention of this compact course is to give a broad introduction to the phenomena which aect the resistance of structures against damage and collapse caused by earthquakes. The scientic methods, on which the analysis of structural behaviour under seismic loads is based, are derived from rst principles. The topics of the course are treated in the sequence in which the corresponding events occur during an earthquake.     

The analysis of the dynamic behaviour of the structure is a well-established discipline of civil engineering. In engineering practice, it is frequently necessary to consider not only the structure itself but also the ground, liquids and gases with which it interacts. The large variety of phenomena, which are observed in dynamic behaviour, and the complexity of the interaction between the frequency spectra of the structure and its dynamic loading, have stimulated a great volume of the research leading to the very extensive treatment of structural dynamics topics in various types of publications and research reports. This situation raises the question how the large body of existing knowledge and experience can be passed on to those who stand at the beginning of their involvement with structural dynamics, particularly to students at our educational institutions.

The aim of this course is to provide an overview in which the main topics associated with the dynamic analysis of structures, the ground on which their foundations and basements rest are treated coherently. In order to avoid the large eort, which is required if knowledge on a topic must be collected from several books and papers with dierent approaches and notations, this course is self-contained. The reader is assumed to be familiar with the widely taught and standardized treatment of partial dierential equations and with matrix algebra, but not with any topics of structural dynamics. Only topics treated in the lecture notes are assumed to be known when a topic is treated in the course. Other publications are named in the reference list of the script so that the treatment of topics in the book can be compared to the treatment of the same topics in other texts, but the material in the additional publications is not required to develop an understanding of the material covered in this course.

Throughout the course, the theories, derivations and formulations are presented such that they can readily be cast into the software. The software itself is not listed in the script. In some cases, such software has been used to prepare diagrams which illustrate typical aspects of the dynamic behaviour of structures as well as their interaction with ground and uids. These diagrams are included in the script.