A direct method for determining floor response spectra at the ITER Tokamak Complex

A suitable methodology to find the seismic floor response spectra (FRS) at a particular location of a structural system by a direct spectra-to-spectra method is presented in this work. This methodology was developed to obtain FRS inside the ITER Tokamak Complex building and the mechanical devices located in the building, as the Fusion Reactor Machine. Based on the well-established tools developed over the last decades in random vibration theory, the methodology developed totally in the frequency domain, has three main steps: First, the generation of a free-field acceleration PSD functions compatible with the Design Response Spectra; Second, the generation of the absolute acceleration PSD function at the locations of interest within the structure; Third, the determination of the FRS. To demonstrate the feasibility of the method, the FRS obtained at a different points of the Tokamak Complex are compared with the FRS obtained by means of the classical methods, based on time-histories of absolute acceleration obtained in time-domain. The comparison reveals a great accuracy of the proposed method.