The calculation of structural response

This chapter covers the following topics.

Seismic engineers need to have a good understanding of the dynamic, non-linear response of structures to earthquake loading, and this chapter aims to provide a mainly qualitative introduction to the subject and to the range of analytical techniques that are available for calculating structural response.

Earthquake loading poses the structural analyst with one of the most challenging problems in engineering. A violent and essential unpredictable dynamic ground motion imposes extreme cyclic loads on engineering materials whose response under such conditions is complex and incompletely understood. If this is the case, engineering designers for whom this book is written may wonder whether there is any point in their getting to grips with the complex underlying theory of dynamic seismic analysis. In fact, current methods of analysis provide important insights into the way that structures respond to earthquakes, and hence the ways in which designers can control this response. Moreover, a basic understanding of analytical principles is essential to enable an informed and critical use to be made of computer-generated results, which form the basis for most seismic analysis and design. Therefore in the author's view earthquake engineers must make the effort to understand the basics of dynamic seismic analysis. To obtain a thorough understanding of the subject, reference needs to be made to some of the classic texts on the subject, for example Clough and Penzien (1993) and Chopra (2012), which are, however, lengthy and require considerable effort.