An isogeometric approach for vibration characteristics analysis of functionally graded triply periodic minimal sandwich curved-doubly shell integrated with magneto-electro surface layers subjected to low-velocity impact load

In this paper, the isogeometric analysis (IGA) method is employed to analyze the oscillation characteristics of functionally graded triply periodic minimal surface (FG-TPMS) curved-doubly shells integrated with magneto-electric surface layers (referred to as "FG-TPMS-MEE curved-doubly shells") subjected to low-velocity impact loads. This study presents low-velocity impact load model based on a single spring-mass (S-M) approach. The FG-TPMS-MEE curved-doubly shells are covered with two magneto-electric surface layers, while the core layer consists of three types: I-graph and Wrapped Package-graph (IWP), Gyroid (G), and Primitive (P), with various graded functions. These types are notable for their exceptional stiffness-to-weight ratios, enabling a wide range of potential applications. The Maxwell equations and electromagnetic boundary conditions are applied to compute the change in electric potentials and magnetic potentials. The equilibrium equations of the shell are derived from a refined higher-order shear deformation theory (HSDT), and the transient responses of the FG-TPMS-MEE curved-doubly shells are subsequently determined using Newmark's direct integration method. These results have applications in structural vibration control and the analysis of structures subjected to impact or explosive loads. Furthermore, this study provides a theoretical prediction of the low-velocity impact load and magneto-electric-elastic effects on the free vibration and transient response of FG-TPMS-MEE curved-doubly shells.