An Electric Node Concept for Solid-Shell Elements for Laminate Composite Piezoelectric Structures

The eight-node solid-shell finite element models have been developed for the analysis of laminated composite plate/shell structures embedded with piezoelectric actuators and sensors. To resolve the locking problems of the solid-shell elements in laminated materials and improve accuracy, the assumed natural strain method and hybrid stress method are employed. Introduction of the concept of the electric nodes can effectively eliminate the burden of constraining the equality of the electric potential for the nodes lying on the same electrode. Furthermore, the nonlinear electric potential distribution in piezoelectric layer is described by introducing internal electric potential. The developed finite element models, especially electric potential node model, are simpler over other models but can still obtain same accuracy as exact solution described. Several examples are studied and compared with exact solution and other predicted results to illustrate the accuracy of the present model, and efficacy and effect caused by nonlinear electric potential distribution on frequency and electric fields in smart structure modeling.