Modeling, Analysis and Design of SMART Composite Structures and Curved Actuators.

摘要

A general framework has been developed for the analysis of laminated smart structures with embedded and/or surface bonded piezoelectric actuators and sensors. The theory addresses the following issues: (1) accurate description of transverse shear effect in the laminated structural model, (2) presence of multiple delaminations and (3) characterization of delamination placement and size on dynamic characteristics. The mathematical model has been implemented using finite element method and extensive numerical investigations have been performed to validate the model with three-dimensional results and available experimental data. Results indicate that the presence of delaminations affect the modal strain distributions in smart composite laminates. The developed theory has been used to characterize delaminations in smart composite plates of arbitrary thickness and results indicate that dynamic strain is a better indicator of damage than frequencies or mode shapes. Significant differences are noted in the RMS values of the response, calculated using modal strain, indicating the presence of damage. A control system has also been designed to minimize the effect of damage. New damage indices based on modal strain are proposed and show promising results.