Strong ground motions in the near field to the fault rupture mechanism, due to the presence of large and energetic pulses in the relevant time history, can produce and induct the seismic wave-type behavior in the continuum contour of the site and strongly affect the variation domain of the structures response parameters. This trend is such that there is a significant increase in the possibility of extensive structural damage and the occurrence of dynamic instability modes. Therefore, evaluating the seismic performance of structures under such strong ground motions is very complex and many factors are involved in it.

In this study by using several mathematical parametric expressions with the ability to fit the shape of the velocity and acceleration pulse, the waveform structures in the time history of near-field records have been modeled and adjusted. The process of simulation and closed-form fits was performed in a way that in addition to matching the existing pulses in the velocity and acceleration time histories, the diagram of cumulative changes of kinetic energy also has a good agreement with the corresponding one related to the real record. In addition to modeling velocity pulses, diagram of cumulative changes of energy release under artificial time series and the real record has also been calculated and compared. The results of this study describe the features and functionalities for the closed form-fitting model in performing simulations and computational validation on strong earthquake records.