Partial and Segmented Modal Sensors for Beam Structures

Abstract

The idea of using shaped sensors, and to a lesser extent actuators, for beam- and plate-type structures has been a subject of intense interest for many years. Typically for beam-type problems, the sensor width is varied along the length of the beam. The shape of the sensor is obtained by considering the modes of the beam and usually requires that the sensor covers the whole beam. This paper extends the previous results for distributed sensors for beams in two ways: the optimum sensor shapes that cover only a portion of the beam-type structures are derived and the optimum shapes for segmented sensors, that enable multiple modes to be sensed, are derived. The effect of geometric tolerances and the sensor output response to higher modes has been established. Although it is possible to derive the required sensor shapes, geometric tolerances will often make these sensors difficult to manufacture. The approach is demonstrated with a pinned-pinned beam example.