Methods and apparatus for monitoring structural members subject to transient loads

摘要

A method and apparatus for monitoring the structural acoustic signature of a structural member in response to a transient load, corresponding to detected vibration frequencies transmitted by the structural member including the fundamental and harmonic frequencies of the structural member, to determine changes in structural integrity and to determine the nature and type of transient loads. The structural acoustic signature of the structural member in a first condition in response to a first transient load is compared to a structural acoustic signature from a second transient load whereby differences in the signatures correspond to the occurrence of changes in the elastic qualities or condition of the structural member. The signatures are preferably evaluated in the frequency domain. The nature and type of transient load can be determined by evaluating the waveform shape of a structural member in response to the unknown load against a history of waveform shapes corresponding to known laods. A plurality of remote structural members such as highway bridges may be monitored by a central station.