Nonlinear Analyses of Porous Functionally Graded Sandwich Piezoelectric Nano-Energy Harvesters under Compressive Axial Loading

Abstract

In this study, a sandwich piezoelectric nano-energy harvester model under compressive axial loading with a core layer fabricated of functionally graded (FG) porous material is presented based on the nonlocal strain gradient theory (NSGT). The von Karman type geometric nonlinearity and the axial loading were considered. The electromechanical governing equations were obtained using Hamilton’s principle. The nonlinear vibration frequencies, root mean square (RMS) voltage output and static buckling were obtained using the Galerkin method. The effects of different types of porous distribution, porosity coefficients, length scale parameters, nonlocal parameters, flexoelectricity, excitation frequencies, lumped mass and axial loads on the natural frequency and voltage output of nanobeams were investigated. Results show that the porous distributions, porosity coefficient of porous materials, the excitation frequencies and the axial load have a large effect on the natural frequency and voltage output of the sandwiched piezoelectric nanobeams. When the NSGT is considered, the critical buckling load depends on the values of the nonlocal parameters and strain gradient constants. In addition, the electromechanical conversion efficiency of the post-buckling process is significantly higher than that of the pre-buckling process. The flexoelectric effect can significantly increase the RMS voltage output of the energy harvester.

Three-Dimensional Thermoelasticity Analysis of Viscoelastic FGM Plate Embedded in Piezoelectric Layers under Thermal Load

“…By solving Equation (45), the displacement components at the bottom surface of the sensor layer u 0 v 0 w 0 are obtained; then, using Equations ( 23), (26), and (37), mechanical and electrical state variables can be computed. Finally, modified Dubner's and Abats's numerical techniques are employed to transform the displacement and stress fields from Laplace to the time domain [39].…”

“…Using the meshless methods and third-order shear deformation theory, Moradi-Dastjerdi and Behdinan [25] analyzed thermo-electro-mechanic behaviors of the sandwich FG plate attached to piezoelectric layers in the framework of HSDT. Using a sandwich nanobeam model, the electromechanical response of a piezoelectric energy harvester under compressive axial load was considered by Zeng et al [26] for both prebuckling and postbuckling states, utilizing the Galerkin technique and the harmonic balance method. Xiang and Shi [27] investigated the thermo-viscoelastic behavior of beams made of FG piezoelectric material (FGPM) using the Airy stress function based on elasticity theory.…”

Nonlinear dynamic response of bimorph piezoelectric energy harvester with functionally graded porous core

“…By means of porous piezoelectric thin films, a flexible dual-cantilever energy harvester is offered to harvest the mechanical energy from the motion of the pacemaker by Dong et al 37 Shin et al 32 investigated porous sandwich structures based on ceramic piezoelectric materials for energy harvesting applications materials with high piezoelectric charge coefficient and low dielectric constant Fan 38 proposed a nano energy harvester with porous piezoelectric materials based on Biot’s porous elasticity and derived the analytical expressions for the resonant frequencies and the energy capturing ability of the porous energy harvester. A sandwich piezoelectric nano-energy harvester model under compressive axial loading with a core layer made-up FG porous material is presented by Zeng et al 39 with the von Karman type assumption. The effects of various porosity forms, porosity coefficients, length scale, excitation frequencies and lumped on the natural frequency and voltage output of nanobeams were investigated.…”