In practice, earthquake studies are usually carried out using the response spectrum method, as it has many advantages: The application is relatively simple, the calculation takes little time and the results are easy to understand. The method is based on spectra in the form of specific diagrams. They express how the model "responds" to a vibration excitation made in its bearings. In this way, it is possible to draw conclusions about the reaction of the structure in the event of an earthquake.
Response spectra are derived from the records of many earthquakes that have occurred around the world. They are also regulated in the relevant standards such as EN 1998-1 [1] or ASCE 7 [2]. For a detailed explanation of the response spectrum method, see Meskouris [3] and Wilson [4].
The add-on response spectrum method is an extension of the Modal analysis. This makes it possible to carry out earthquake analyzes according to the multimodal response spectrum method. The spectra can be selected in accordance with the standards or created in a user-defined manner. The resulting forces and deformations are then calculated from these specifications.
The currently available design standards and a summary of the functional scope can be found in the product description spectrum method Response spectrum method for RFEM 6/RSTAB 9 .
