Wave propagation in smart laminated composite cylindrical shells reinforced with carbon nanotubes in hygrothermal environments

Wave propagation problem is solved in smart laminated carbon nanotube (CNT)-reinforced composite cylindrical shells coupled with piezoelectric layers on the top and bottom surfaces in hygrothermal environments for the first time. The motion equations are derived based on the first-order shear deformation shell theory considering the transverse shear effects and rotary inertia. The hygrothermal effects are also included in the mathematical modeling and the effective material properties of a CNT-reinforced composite shell are estimated through the Mori-Tanaka micromechanical model. Dispersion solutions are obtained by solving an eigenvalue problem. Parametric studies are carried out to investigate the effects of temperature/moisture variation, CNT volume fraction and orientation, piezoelectricity, shell geometry, stacking sequence, and material properties of the host substrate laminated composite shell at different axial and circumferential wave numbers. The results show that the temperature/moisture variation influences moderately on the dispersion solutions of smart laminated CNT-reinforced composite shells. The presented methodology and results can be used in wave propagation analysis of smart laminated CNT-reinforced composite shells affected by hygrothermal environmental conditions.