scholarly journals Geometrical nonlinearity analysis of a piano hammer using a finite element method

2013 ◽  
Vol 34 (3) ◽  
pp. 219-220
Author(s):  
Hideo Suzuki
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Geometrical Nonlinearity ◽  
Element Method

Modal reduction-based finite element method for nonlinear FG piezoelectric energy harvesters

2021 ◽  
pp. 107754632110481
Author(s):  
Parisa Fatehi ◽  
Mojtaba Mahzoon ◽  
Mehrdad Farid ◽  
Hassan Parandvar
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Initial Conditions ◽  
Geometrical Nonlinearity ◽  
Polymer Materials ◽  
Computational Time ◽  
Accurate Estimation ◽  
Piezoelectric Energy ◽  
Modal Reduction ◽  
Element Method

In this study, harvesting energy from a nonlinear functionally graded (FG) piezoelectric cantilever beam under harmonic excitation is investigated. The material properties of the piezoelectric are assumed to be a combination of piezo-ceramic and piezo-polymer materials for high performance and flexibility. The neutral axis is obtained in order to eliminate bending–stretching coupling. The geometrical nonlinearity and electromechanical coupling are incorporated in the coupled nonlinear equations that are derived using the generalized Hamilton’s principle and solved using the combination of modal reduction and finite element methods. The shooting method is employed to obtain steady-state periodic response of an FG nonlinear harvester with appropriate initial conditions. Also it is shown that at least two-mode approximation is required for accurate estimation of nonlinear response and harvested power. Using the method of nonlinear modal reduction, the unstable branches for frequency domain solution are estimated and the computational time is reduced considerably compared to full finite element method. A case study is also accomplished in detail to analyze the effects of base amplitude values and material distribution on harvested power and bandwidth.

scholarly journals Nonlinear Vibrations of 3D Laminated Composite Beams

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
S. Stoykov ◽  
S. Margenov
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Geometrical Nonlinearity ◽  
Strain Tensor ◽  
Laminated Composite ◽  
Composite Beams ◽  
Orthotropic Materials ◽  
Warping Function ◽  
Laminated Composite Beams ◽  
Element Method

A model for 3D laminated composite beams, that is, beams that can vibrate in space and experience longitudinal and torsional deformations, is derived. The model is based on Timoshenko’s theory for bending and assumes that, under torsion, the cross section rotates as a rigid body but can deform longitudinally due to warping. The warping function, which is essential for correct torsional deformations, is computed preliminarily by the finite element method. Geometrical nonlinearity is taken into account by considering Green’s strain tensor. The equation of motion is derived by the principle of virtual work and discretized by thep-version finite element method. The laminates are assumed to be of orthotropic materials. The influence of the angle of orientation of the laminates on the natural frequencies and on the nonlinear modes of vibration is presented. It is shown that, due to asymmetric laminates, there exist bending-longitudinal and bending-torsional coupling in linear analysis. Dynamic responses in time domain are presented and couplings between transverse displacements and torsion are investigated.

scholarly journals Research on the Behavior of the Steel Plated Shear Wall by Finite Element Method

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
S. M. R. Mortazavi ◽  
M. Ghassemieh ◽  
M. S. Ghobadi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Geometrical Nonlinearity ◽  
Time History ◽  
Shear Wall ◽  
Analytical Models ◽  
Nonlinear Time History Analysis ◽  
Cyclic Behavior ◽  
Wall Structure ◽  
Element Method

From the early’ 70s till today, steel shear walls have been used as the primary lateral force resisting system in some of the significant buildings around the world. To assist understanding the behavior of this system, there have been research programs in USA, Canada, Japan, and UK. This research presents the dynamic and cyclic behavior of steel plated shear wall. In order to simulate the behavior of such a wall structure, finite element method of analysis is implemented. Several analytical models are implemented, in order to obtain the dynamic as well as cyclic behavior of such system. The material nonlinearity as well as geometrical nonlinearity along with the postbuckling behavior of steel plate subjected to cyclic loading has also been employed. The hysteresis diagrams of steel shear wall system in terms of storey shear drift are presented. The results obtained from the analyses are compared to some experimental results reported by other researchers previously. The nonlinear time history analysis of such system is carried out for different seismic response spectra. Finally, the significant factors and parameters of the steel plated shear wall which affect the overall behavior of such system are acknowledged and their effects were recognized.

Simulation of tuning graphene plasmonic behaviors by ferroelectric domains for self-driven infrared photodetector applications

Nanoscale ◽  
2019 ◽  
Vol 11 (43) ◽  
pp. 20868-20875 ◽  
Author(s):  
Junxiong Guo ◽  
Yu Liu ◽  
Yuan Lin ◽  
Yu Tian ◽  
Jinxing Zhang ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Interfacial Effect ◽  
Infrared Photodetector ◽  
The Finite Element Method ◽  
Ferroelectric Domains ◽  
Element Method

We propose a graphene plasmonic infrared photodetector tuned by ferroelectric domains and investigate the interfacial effect using the finite element method.

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