Implementation of a coupled thermo-piezoelectric-mechanical model in the LQG controller design for smart composite shells

The present paper aims to develop a completely coupled thermo-piezoelectric-mechanical theory, based on an improved layerwise displacement field and higher order electrical and temperature fields, to study dynamic response and control of smart composite shells. A variational principle, addressing the interaction between thermal, piezoelectric and mechanical fields, is used to derive the governing equations of equilibrium. Finite element technique is used to ensure application to practical geometry and boundary conditions. Numerical analysis is conducted for simply supported cylindrical shells with distributed self-sensing piezoelectric actuators. Control authority is investigated using Linear Quadratic Gaussian (LQG) theory. Parametric studies are conducted to investigate the effect of two-way coupling, placement of actuators, coupling and flexibility of the primary structure.