Seismic Methods

Folic R., Cosic M.: Seismic Methods (presentation)

The authors of the presentation, on the basis of the analysis of several thousand scientific papers, presented their original systematization of nonlinear seismic methods for structural performance analysis, which were developed in the last twenty years. Nonlinear seismic methods are generally classified into two groups: Nonlinear Static Analyses (NSA) and Nonlinear Dynamic Analyses (NDA). The analyses of non linear seismic structural response were classified separately from the target displacement analysis which defines the relationship of the seismic demand and the seismic response. On the other hand, the classification was also conducted depending on whether a nonlinear response of the system is obtained by the implementation of incremental-iterative procedures or by the implementation of semi-iterative and/or semi-incremental procedures. Nonlinear Dynamic Analyses were classified according to the concept of mathematical formulation, i.e. whether they are based on only one dynamic analysis, several dynamic analyses or are solved in combination with other methods. By implementing the conducted systematization and classification of nonlinear seismic methods, on can very efficiently consider which type of method is optimal for structural analysis and which type of method should be taken into account in the phase of preliminary and final analyses in the course of scientific research and professional projects.

Damping Models

Folic R., Cosic M., Folic B.: Damping Models (presentation)

This presentation shows the aspects of damping modelling in structural analysis through the systematization of damping types and flowcharts, depending on the type of analysis applied: linear and non-linear, static and dynamic. Damping has been systematized based on the way it was introduced into calculations, i.e. over material damping, link element damping and damping directly introduced into the analyses which are conducted in capacitive, time and frequency domains. In the process of creating numerical structural models, the type of damping and the way of its introduction into structural analysis can be very efficiently selected by applying the flow charts developed. By applying the developed flowcharts, alternative approaches to the introduction of damping into structural analysis can also be defined.