Hamid Reza Ahmadi - Faculty of Civil and Environmental Engineering,Tarbiat Modares University, Al-e-Ahmad
Farhad Daneshjoo

A large number of time-frequency distributions have been suggested by researchers. However,their capabilities for signal processing and feature extraction are different. There is nosingle ideal time-frequency distribution for every application. The operator needs to select a distribution that most clearly reveals the information of interest for a given signal. Therefore,in this study, three well known time-frequency distributions consisting of Born-Jordan distribution,Margenau-Hill distribution and Rihaczek distribution were evaluated and assessed to extract dynamic properties from concrete piers of bridges. For this purpose, a finite-elementmodel of a concrete bridge with simple span was used. The model was excited by groundmotion records, and its responses were recorded at the piers. The response signals are processed by the TFDs and related time-frequency plans were calculated. Then, with comparison and evaluation the plans, the optimal TFD for signal processing of concrete piers of bridges under seismic loads was identified.

square time-frequency distribution; concrete piers of bridges; seismic response signals