Torsional stability capacity of a nano-composite shell based on a nonlocal strain gradient shell model under a three-dimensional magnetic field

This paper considers a single-walled composite nano-shell (SWCNS) exposed in a torsional critical stability situation. As the magnetic field affects remarkably nanostructures in the small size, a three-dimensional magnetic field is assessed which contains magnetic effects along the circumferential, radial and axial coordinates system. Based on the results of the nonlocal model of strain gradient small-scale approach and the first-order shear deformation shell theory (FSDST), the problem is estimated. Afterward, the numerical results are taken analytically and compared with other existing literature. Hereafter, the influences of various factors, such as the magnetic field, are discussed deeply. It is observed that when the magnetic field is studied in three dimensions, the transverse magnetic effect is the most serious factor that affects fundamentally the torsional stability of the shell.