Investigation of state vector computational solution on modeling of wave propagation through functionally graded nanocomposite doubly curved thick structures

In this paper, a solution strategy based on the state vector technique is proposed to study the vibroacoustic performance of carbon nanotube (CNT)-reinforced composite doubly curved thick shells employing three-dimensional theory. For this purpose, the properties of the nanocomposite media are investigated by the rule of mixture which includes some productivity parameters. This approach considers various distributions of CNT which can be identical or functionally graded through thickness direction. Since the state vector solution is used to solve the three-dimensional equations of motion, the nanocomposites are divided intoslayers for stress and strain components according to approximate layer model along with local transfer matrix. This process is followed by the global transfer matrix for all of the layers of thick shell. After obtaining the sound transmission loss of structure, various configurations are presented to validate the results. Hence, not only the precision of the formulation is confirmed but also the importance of considering the three-dimensional theory is remarked due to very reliable outcomes at high-frequency domain for CNT-reinforced composite thick shells. Furthermore, it is shown that the CNTs are able to enhance the sound insulation property of doubly curved structures. Finally, a new approach is made to present the sound pressure level of CNT doubly curved shells with respect to various CNT materials in different distributions.