Shahrood University of Technology Journal of Solid and Fluid Mechanics 2251-9475 14 5 2024 11 21 Comparison of nonclassical controllers on piezoelectric nanoresonator: natural ‎frequency and pull in voltage analysis Comparison of nonclassical controllers on piezoelectric nanoresonator: natural ‎frequency and pull in voltage analysis 109 120 3378 10.22044/jsfm.2025.14362.3849 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 Due to the importance of the application of piezoelectric nanostructures and due to their mass and small size ‎at the nano level, parameters depending on the size and surface energy should be included in the theoretical ‎models of their dynamic analysis and mathematical modeling. In current work, some nonclassical controller ‎effects such as strain gradient (SGT), nonlocal (NLT) and Gurtin–Murdoch surface/interface (GMSIT) ‎theories are presented for analyzing of nonlinear vibration in piezoelectric nanoresonator (PENR) compared ‎to classical theory (CT). PENR subjected to nonlinear electrostatic excitation with direct (DC) and ‎alternating (AC) voltages and also visco-pasternak medium. For this analysis, Hamilton’s principle, ‎Galerkin technique, combination of Complex averaging method and arc-length continuation are used to ‎analyze 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 the dimensionless natural ‎frequency, resonant frequency, resonance amplitude, nonlinear behavior and the system's instability of ‎PENR.‎ Due to the importance of the application of piezoelectric nanostructures and due to their mass and small size ‎at the nano level, parameters depending on the size and surface energy should be included in the theoretical ‎models of their dynamic analysis and mathematical modeling. In current work, some nonclassical controller ‎effects such as strain gradient (SGT), nonlocal (NLT) and Gurtin–Murdoch surface/interface (GMSIT) ‎theories are presented for analyzing of nonlinear vibration in piezoelectric nanoresonator (PENR) compared ‎to classical theory (CT). PENR subjected to nonlinear electrostatic excitation with direct (DC) and ‎alternating (AC) voltages and also visco-pasternak medium. For this analysis, Hamilton’s principle, ‎Galerkin technique, combination of Complex averaging method and arc-length continuation are used to ‎analyze 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 the dimensionless natural ‎frequency, resonant frequency, resonance amplitude, nonlinear behavior and the system's instability of ‎PENR.‎ https://jsfm.shahroodut.ac.ir/article_3378_e2984e7960d3aa4d9851b55832ac0b8c.pdf