Static and dynamic analysis of peizothermoelastic laminated shell composites with distributed sensors and actuators

In the development of smart shell composite structures, piezoelectrics are widely used as sensors and actuators for monitoring and controls of structural systems. The objectives of this research are: (1) to develop a new theory for a thick/thin piezothermoelastic laminated shell composite; (2) to study shell's dynamic behaviors, and (3) to study its sensor and control characteristics.; The shell structure is made of multi-layer laminae and each lamina could be a host composite material, a sensor layer or an actuator layer. In this dissertation a new generic theory for nonlinear piezothermoelastic laminae is developed. The nonlinear piezothermoelastic shell equations and boundary conditions are derived using Hamilton's principle. The equations are also simplified to account for thin shell composites, in which the Kirchhoff-Love thin shell assumptions are employed. The equations are further simplified to a Linear case in which the strain-displacement relations are linear when the deflections are reasonably small. As applications of geometric nonlinear theory, case studies are discussed for specific materials and specific geometries.; Natural frequencies, mode shapes, and modal dampings for the generic piezothermoelastic shell composites are investigated. Forced vibrations are discussed where excitation forces include mechanical, electric, and temperature forces. Sensor outputs of the piezoelectric layer due to the direct piezoelectric effect and pyroelectric effect, as well as distributed actuator are discussed.; The developed theories are applied to the laminated cylindrical shell composites. Its natural frequencies and mode shapes are evaluated in the simply supported boundary condition. Generic solution procedures for the response are derived and applied to the cylindrical laminated shell composites. Numerical examples are provided to illustrate the multi-field step and impulse responses. Dynamics and feedback control effectiveness of this shell with curvature changes are evaluated. A theory of segmented sensor, actuator, and feedback vibration control for cylindrical shell is provided. The shell considered in this case is a three elastic composite laminae sandwiched between two piezoelectric laminae. Detailed segmented sensor/actuator electromechanics, membrane/bending contributions, and spatial effects are studied.; By considering geometric nonlinear effect, piezothermoelastic beam and plate composites are discussed. Static deflections are solved under static electric and/or temperature loads. Dynamic behaviors and control effects of the composite with an initial large static deflection are studied. Parametric studies are conducted and numerical examples are provided.