STRUCTURAL MODAL TESTING WITH VARIOUS ACTUATORS AND SENSORS

This paper presents the theoretical formulation of generic frequency r esponse functions (FRFs) for continuous systems associated with variou s forms of actuation and sensing methods. The generic actuator and sen sor eigenfunctions are identified and interpreted physically. The FRF can then be expressed in a conventional modal format. The testing proc edure by roving the sensor with the fixed actuator results :in the sen sor eigenfunction after the extraction of modal parameters. In contras t, roving :he actuator with the fixed sensor results in the actuator e igenfunction. The physical meanings of the extracted mode shapes are s hown to be characterised by the form of the actuators and sensors. The lateral vibration of a one-dimensional beam problem is illustrated to demonstrate the applications of various forms of actuators and sensor s to structural modal testing. Three types of actuators and three type s of sensors are considered, and the feasibility of structural testing for applying any combination of the actuators and sensors is shown. T his work provides the theoretical base for applying various forms of a ctuators and sensors to structural modal testing. (C) 1998 Academic Pr ess.