Modal Parameter Estimation for Piezostructures

Abstract

This paper is motivated by the need for consistency between piezostructure measurements and existing modal analysis approaches. Fundamental relationships are developed which reveal that the existing framework of traditional modal analysis approaches can be used to estimate modal parameters which describe the piezostructure dynamics. The modal analysis technique is a frequency domain method where the relationship between pole-residue models for conventional structures and piezostructures is developed. Since typical arrangements of piezoelectric sensors and actuators for modal testing lead to ambiguous mode shape estimates, the use of sensoriactuator transducers provides critical drive-point response information. Also, the existence of a transformation between the structure’s modal matrix and the piezostructure’s electromechanical coupling matrix is shown. It is shown that combining the results of a traditional modal test and a piezostructure modal test enables a modal filtering operation which produces experimental measurements of the electromechanical coupling matrix. This method of modal analysis of a piezostructure is demonstrated numerically for a cantilevered beam.