Structural energy flows in water filled pipes: implementation of measurement technique based on PVDF reusable strain gauges

The purpose of this work is an implementation the newly developed measurement technique for structural energy estimation in-situ. The technique based on reusable PVDF strain gauges in measurement of structural energy flows transferred by longitudinal and shear forces, bending and torsional moments in water filled pipes are presented and discussed. Developed technique was implemented for determination of the efficiency of noise control means in the pipeline with the test rig "Flow". The technique also applied in order to determine the components of vibrational energy flows generated by pump incorporated into the rig "Impedance". Measurements were performed when real pumps have been run. The relationships between four structural components in pipe walls and water ones transferred with plane waves in the pipe channel were determined. Degree of uncertainty in proposed technique was revealed using error analyses taking into account the real data about coherence function and measured phase angle between force/moment and linear/angular velocity. The reliability of preformed measurements at tonal components of structural energy spectra proofed employing an error analyses and energy balance calculation in pipe cross section. The possibilities and limitations of the technique were addressed.