Nonlinear Dynamic Analysis of Functionally Graded Carbon Nanotube-Reinforced Multilayer Composite Plates Under Blast Loading Using Isogeometric Analysis

The occurrence of an explosion generates wave propagation in the surrounding environment, exposing nearby structures to intense dynamic excitations. These excitations may cause instantaneous deformations, structural damage, or even complete collapse. In this study, the dynamic response of multilayer functionally graded carbon nanotube-reinforced composite (FG-CNTRC) plates under blast loading is investigated using the von Karman assumptions and first-order shear deformation theory. The governing equations are discretized via an isogeometric numerical method utilizing B-spline basis functions. A semi-analytical multiple time-scale method is employed to solve the nonlinear forced vibration differential equation. Both transient and steady-state responses are analyzed, and for the first time, a closed-form time-domain solution is derived for the nonlinear forced vibration of FG-CNTRC plates subjected to blast loading. The novelty of this study lies in the integration of the isogeometric method with von Karman nonlinearity and a semi-analytical time-domain approach to capture the transient and steady-state behavior of FG-CNTRC plates. A detailed parametric study is conducted for five distinct CNT distribution patterns and various lamination sequences, revealing their effects on nonlinear frequency ratios, vibration attenuation, and blast resilience. The proposed framework offers both accuracy and efficiency in modeling high-rate dynamic responses of composite structures.