Multi-Degree-of-Freedom Linear Modal Analysis And Application In Bridge Testing

Vibration testing has experienced half century. In the 1970's, vibration testing technology entered into a important phase. In this time, as a result of major development in computer technologies and Fast Fourier Transform wider application, many frequency analyzer based on digital signal processing theory and multi-function signal analysis software occurred. Which greatly strengthened analysis function to engineer vibration signal's time field and frequency field.Vibration testing method is inverse processing of theory analysis method. It main requires some excitation to make testing objects produce vibration response. Directly presenting the charactestic of excitation and system vibration response by seismometer (e.g. characterstic of displacement, velocity and acceleration). And then obtaining the system modal characterstic by analog signal analysis or digital signal analysis. At present, modal analysis technology has been a important engineer technology in China, it has been a important part of vibration engineer. Modal analysis or experimental modal analysis become a very important method for all kinds of product design and function estimation.