As non-linear dynamic analysis (NLDA) is becoming more prevalent in codes and practice, there is a need to consolidate ground motion record selection and modification procedures from a structural engineering perspective. There are currently many options in seismic input selection and modification for NLDA available but little guidance is available to practitioners on which methods are appropriate for their specific application.

In this paper, the non-linear response of a code-conforming four-story reinforced concrete (RC) frame building is analyzed; the aim is to compare, in terms of inelastic seismic response, different options to obtain sets of accelerograms for NLDA. The study is code-based and then spectral-shape based; all the considered sets of records match, on average (in a range of periods) or individually (at the fundamental vibration period of the structure), the same target (i.e. design) spectrum for a case-study site in southern Italy. Additional criteria in terms of earthquake source parameters (i.e., magnitude and source-to-site distance)  and site classification are considered.

As structural response measures, or engineering demand parameters (EDPs), maximum inter-story drift ratio (MIDR), roof drift (RD) and the total (cumulative) hysteretic energy (EH) are considered to relate the ground motions to both peak and cyclic structural demand.

Analysis results show little evidence to support the need for a careful site-specific process of record selection by magnitude, distance and soil class once spectral matching is assured. Moreover, results indicate that the linearly scaled records do not show significant differences with respect to the unscaled records, for both peak and cyclic response parameters, suggesting that linear scaling is a fair procedure, as many studies point out, if the spectral shape is controlled.

Finally, it is discussed how, when selecting and scaling ground motion records, one can improve the resulting structural response prediction by taking into account integral record properties, other than spectral accelerations, that may be important to the non-linear cyclic response.