Experimental Spatial Power Flow Using a Scanning Laser Doppler Vibrometer

Abstract

Abstract An experimental spatial power flow (ESPF) method which computes the energy path continuously over the surface of a vibrating structure is presented. The ESPF method is a novel approach based on a spatially dense representation of the system’s dynamics obtained by solving for the 3-D complex-valued velocity field from experimental data acquired by a scanning laser Doppler vibrometer (SLDV). Quintic B-spline surfaces used to represent the extracted velocity field allow the power flow to be computed continuously over the surface of the structure. The active and reactive power flow components are kept separate throughout the solution. To validate the ESPF concept, power flow results of a prescribed velocity field were compared with simulated experimental results. The power flow computed from the prescribed velocity field compared closely to the power flow computed from the simulated experimental results indicating the validity of the ESPF concept. The ESPF method was then applied to a simply supported thin steel plate. The experimental power flow results distinctly show the locations of the energy sources and sinks and identify the energy path in the plate.