Influence of rotational component of earthquake excitation to the response of steel slender frame

This work is about the influence of rotational component of earthquake excitation to the response of high steel slender frames. In most of studies seismic input is being represented by translational only component of ground accelerations while the rotational one is ignored. This was due to the luck of records which measure the rotational component. Nowadays, technology provides such an instruments and relative records can be found. Elastic design response spectra for rotational components are introduced in regulations. Furthermore, the rotational component was not taken into account since its influence in low structures is not significant. In this paper the results in response and in internal forces of rotational component to the slender steel frame is examined. Time history analysis of a ten-story steel frame with and without rotational excitation component is performed. From the numerical results it is shown that the impact of rotational component in response and the internal forces of the frame is significant and should not be ignored to the design of structures.