Applied Conceptual Investigation of Earthquake Record Data in the Time Domain and its Relationship with the Frequency Domain by Using Rapid Screening Method (case study: Sarpol-e-Zahab Earthquake)

Engineers usually pay attention to Peak Ground Acceleration (PGA) and the approximate duration of the record when dealing with the acceleration time history. However, according to the basic principles of dynamics, vibrations, and Fourier transform and understanding of the intensity of earthquake and its related parameters from the fundamentals of earthquake engineering, it is possible to obtain a relatively accurate understanding and prediction of the characteristics of the frequency domain and the intensity of the earthquake by taking a careful and deeper look at the time history. The importance of such a skill in performing dynamic analyses is doubled. The process of selecting and scaling records will be also done with higher accuracy if there is such a skill. In this paper, a careful and heuristic view at the time history and its relationship with the frequency domain is presented based on the analysis of Sarpol-e-Zahab earthquake records in the SeismoSignal software. The results indicate that there is a good agreement between the conclusions from the time history and the frequency domain, and by looking carefully at the time history of the earthquake record, an important part of its characteristics can be discovered before performing the frequency domain analyses. For dynamic analysis and understanding the relations between the record and the response of the structures and their failures, visual understanding of earthquake time history is also very important. According to the case study presented in this paper, it is possible to achieve such a skill based on the principles of earthquake engineering and the applied mathematics.