The Location of Building Defects Using Structural Intensity

Many defects in the construction of buildings act as transmission paths across which unwanted sound can travel. The resulting increase in power flow can be measured using structural intensity techniques and the location of the source found from the intersection of two or more intensity vectors. This technique can be used to locate a source (or sometimes a sink) when the intensity being measured is above the residual or background intensity.

Some applications of this technique are discussed and it is used to locate a point source on a concrete floor and a line source exciting a concrete block wall. The technique was found to work well for a point source but was less reliable for a line source. This was partly because a line source is less well spatially defined and partly because the damping of the wall was low, resulting in a high residual intensity.