A Complete description of intensity fields of thin isotropic plates for flexural waves in general field conditions

In engineering practice, structural intensity gives valuable information of sources and sinks of vibration excitations as well as a detailed knowledge of energy propagation through structures. As a result, proper damping treatment can be employed to mitigate noise and vibration harness (NVH) problems. In this paper, a complete description of general vibration intensity fields (W/m) in the frequency domain for isotropic plates is formulated considering flexural waves which is not based on some approximation such as far-field conditions. An 8-point transducer array is required to get an intensity vector in a particular direction taking into account as many as fifteen cross-spectra of field signals. A multi-channel FFT analyser is useful for this measurement. However, one transducer frequency response method is also employed to estimate these cross-spectra alternately. It gives the measurements free from phase mismatch errors.