Shahrood University of Technology Journal of Solid and Fluid Mechanics 2251-9475 14 3 2024 07 22 Comparison of nonclassical controllers on piezoelectric nanoresonator: nonlinear ‎frequency response and stability analysis Comparison of nonclassical controllers on piezoelectric nanoresonator: nonlinear ‎frequency response and stability analysis 125 139 3267 10.22044/jsfm.2024.14369.3851 FA Sayyid H. Hashemi Kachapi Assistant Professor, Department of Mechanical Engineering, University of Mazandaran, Babolsar, Islamic Republic of ‎Iran S. Gh. Hashemi Kachapi Ph.D. Student, Department of Physics, University of Kashan, Kashan, Islamic Republic of Iran Journal Article 2024 04 01 In current study, nonlinear vibrations and stability analysis of piezoelectric nanoresonator (PENR) ‎considering with the effects of non-‎classical controllers such as strain gradient (SGT), nonlocal (NLT) and ‎Gurtin–Murdoch surface/interface ‎‎(GMSIT) theories are presented in comparison with the classical theory ‎‎(CT). PENR subjected to nonlinear ‎electrostatic excitation with direct (DC) and alternative (AC) voltages ‎and also visco-pasternak medium. For ‎this work, Hamilton’s principle and Galerkin technique are used to ‎obtain the governing ‎equations and boundary conditions and also to solve the equation of motion. Complex ‎averaging method ‎combined with arc-length continuation is used to investigate nonlinear frequency response ‎and stability ‎analysis of PENR. The results show that ignoring small-scale and surface/interface effects give ‎inaccurate ‎predictions of vibrational response of the PENR. It is indicated that in different boundary ‎condition, material ‎length scale and nonlocal scale parameters respectively lead to decreasing and increasing ‎of PENR stiffness ‎and also the amplitude of oscillation and the range of instability of non-classic theories of ‎NLT and SGT are ‎greater than that of the classical one. Also changes of surface/interface parameters lead to ‎decreasing or ‎increasing of the resonant frequency, resonance amplitude, nonlinear behavior and the ‎system's instability of ‎PENR.‎ In current study, nonlinear vibrations and stability analysis of piezoelectric nanoresonator (PENR) ‎considering with the effects of non-‎classical controllers such as strain gradient (SGT), nonlocal (NLT) and ‎Gurtin–Murdoch surface/interface ‎‎(GMSIT) theories are presented in comparison with the classical theory ‎‎(CT). PENR subjected to nonlinear ‎electrostatic excitation with direct (DC) and alternative (AC) voltages ‎and also visco-pasternak medium. For ‎this work, Hamilton’s principle and Galerkin technique are used to ‎obtain the governing ‎equations and boundary conditions and also to solve the equation of motion. Complex ‎averaging method ‎combined with arc-length continuation is used to investigate nonlinear frequency response ‎and stability ‎analysis of PENR. The results show that ignoring small-scale and surface/interface effects give ‎inaccurate ‎predictions of vibrational response of the PENR. It is indicated that in different boundary ‎condition, material ‎length scale and nonlocal scale parameters respectively lead to decreasing and increasing ‎of PENR stiffness ‎and also the amplitude of oscillation and the range of instability of non-classic theories of ‎NLT and SGT are ‎greater than that of the classical one. Also changes of surface/interface parameters lead to ‎decreasing or ‎increasing of the resonant frequency, resonance amplitude, nonlinear behavior and the ‎system's instability of ‎PENR.‎ Piezoelectric nanoresonator Nonlocal strain gradient theory Gurtin–Murdoch surface/interface Nonlinear ‎frequency response Complex averaging method. ‎ https://jsfm.shahroodut.ac.ir/article_3267_ea1a572483bf3b8bc70b3bc2c39eceda.pdf