Active Control of Thermally Induced Vibrations in Smart Structure Instrumented with Piezoelectric Materials

2014 ◽  
Vol 612 ◽  
pp. 169-174 ◽  
Author(s):  
Anshul Sharma ◽  
C.K. Susheel ◽  
Rajeev Kumar ◽  
V.S. Chauhan
Keyword(s):  
Finite Element ◽  
Fuzzy Logic ◽  
Negative Feedback ◽  
Fuzzy Logic Controller ◽  
Coupling Effect ◽  
Shear Deformation Theory ◽  
Smart Structure ◽  
Feedback Controller ◽  
Mechanical Coupling ◽  
Degenerated Shell Element

In this paper, a finite element model of piezolaminated composite shell structure is developed using nine-noded degenerated shell element. The stiffness, mass and thermo-electro-mechanical coupling effect is incorporated in finite element modeling using first order shear deformation theory and linear piezoelectric theory. The sensor voltage is calculated using the same formulation and fuzzy logic controller is used to calculate the actuator voltage. The fuzzy logic controller is designed as double input-single output (DISO) system using 49 If-Then rules. The performance of fuzzy logic controller is compared with convention constant-gain negative feedback controller. The simulation results illustrate the superiority of fuzzy logic controller over constant-gain negative feedback controller.

Active Vibration Attenuation of Smart Shell Structure Instrumented With Piezoelectric Layers

2018 ◽  
pp. 22-49 ◽  
Author(s):  
Anshul Sharma
Keyword(s):  
Finite Element ◽  
Fuzzy Logic ◽  
Spherical Shell ◽  
Active Control ◽  
Degrees Of Freedom ◽  
Fuzzy Logic Controller ◽  
Equations Of Motion ◽  
Piezoelectric Sensor ◽  
Smart Structure ◽  
Fuzzy Logic Approach

The active control of vibration of piezoelectric flexible smart structure is an important issue in engineering. Reducing vibration may improve the user's comfort and safety. This chapter presents a fuzzy logic approach for active control of vibration of a smart composite laminated spherical shell. The spherical shell is in the form of a layered composite shell having collocated piezoelectric sensor/actuator pair. The vibratory response of the shell is modeled using finite element method. There are five mechanical degrees of freedom per node and the potential difference across the piezoelectric layer is introduced as an additional electrical degree of freedom on an element level. The mode superposition method has been used to transform the coupled finite element equations of motion in the physical coordinates into a set of reduced uncoupled equations in the modal coordinates. The simulation results illustrate that the superiority of designed nonconventional fuzzy logic controller over conventional controllers.

Analysis of the Electro-Mechanical Responses of the Piezoelectric Motor Based on Finite Element Method

2014 ◽  
Vol 697 ◽  
pp. 181-186
Author(s):  
Zi Lei Wang ◽  
Tian De Qiu
Keyword(s):  
Finite Element ◽  
Coupling Effect ◽  
Complex Stress ◽  
Piezoelectric Resonator ◽  
Element Analysis ◽  
Mechanical Coupling ◽  
Mechanical Responses ◽  
Stress Boundary Condition ◽  
Piezoelectric Field ◽  
Stress Boundary

The piezoelectric field and structure field of piezoelectric resonator of ultrasonic motor are intercoupling. It is difficult to obtain the solution under some circumstances because of the complex stress boundary condition and the influence of coupling effect. An electro-mechanical coupling finite-element dynamic equation is established on the basis of the Hamilton’s Principle about piezoceramic and elastomer. The equation is decoupled through the shock excitation of the piezoelectric resonator and the piezoelectricity element and material provided by finite-element analysis. As a result, an admittance curve as well as the distribution status of the nodal DOF is obtained, which provides an effective method to solve electro-mechanical coupling problems.

Influence of coupled fields on free vibration and static behavior of functionally graded magneto-electro-thermo-elastic plate

2017 ◽  
Vol 29 (7) ◽  
pp. 1430-1455 ◽  
Author(s):  
Vinyas Mahesh ◽  
Piyush J Sagar ◽  
Subhaschandra Kattimani
Keyword(s):  
Finite Element ◽  
Electric Fields ◽  
Elastic Plate ◽  
Coupling Effect ◽  
Shear Deformation Theory ◽  
Functionally Graded ◽  
Finite Element Formulation ◽  
Geometrical Parameters ◽  
Element Formulation ◽  
Elastic Plates

In this article, the influence of full coupling between thermal, elastic, magnetic, and electric fields on the natural frequency of functionally graded magneto-electro-thermo-elastic plates has been investigated using finite element methods. The contribution of overall coupling effect as well as individual elastic, piezoelectric, piezomagnetic, and thermal phases toward the stiffness of magneto-electro-thermo-elastic plates is evaluated. A finite element formulation is derived using Hamilton’s principle and coupled constitutive equations of magneto-electro-thermo-elastic material. Based on the first-order shear deformation theory, kinematics relations are established and the corresponding finite element model is developed. Furthermore, the static studies of magneto-electro-elastic plate have been carried out by reducing the fully coupled finite element formulation to partially coupled state. Particular attention has been paid to investigate the influence of thermal fields, electric fields, and magnetic fields on the behavior of magneto-electro-elastic plate. In addition, the effect of pyrocoupling on the magneto-electro-elastic plate has also been studied. Furthermore, the effect of geometrical parameters such as aspect ratio, length-to-thickness ratio, stacking sequence, and boundary conditions is studied in detail. The investigation may contribute significantly in enhancing the performance and applicability of functionally graded magneto-electro-thermo-elastic structures in the field of sensors and actuators.

Development of Numerical Code for Coupling Dynamical Response of Typical Tokomak Structures Using Volumetric Finite Element

2013 ◽  
Author(s):  
Zhensheng Yuan ◽  
Weixin Li ◽  
Jingyi Xu ◽  
Wenjing Wu ◽  
Zhenmao Chen
Keyword(s):  
Magnetic Field ◽  
Finite Element ◽  
Coupling Effect ◽  
Time Integration ◽  
Numerical Code ◽  
Dynamical Response ◽  
Vacuum Vessel ◽  
Integration Algorithm ◽  
Simulation Accuracy ◽  
Mechanical Coupling

Aiming to simulate the dynamical response of a non-ferromagnetic conductive structure in a strong magnetic field, a code of finite element method (FEM) was developed based on the reduced vector potential (Ar) method and a step by step time integration algorithm. The electromagneto-mechanical coupling effect was taken into consideration by adding ν × B term in the eddy current governing equation to calculate the additional electric field induced by the movement of the structure. The hexahedral isoparametric element was adopted in this code in order to simplify the correspondence between the simulation of electromagnetic force and the dynamical response, which enables the application of the code developed by authors to more complicated structures. To verify the validity of the new numerical code, the benchmark problem (TEAM-16) as a simplified model of Tokamak vacuum vessel structure was simulated. By numerical results contrasted between the current code and the ANSYS software, the code was proved to be more effective than typical commercial codes for structural analysis of a magneto-mechanical coupling problem. The simulation results proved that the new code can improve simulation accuracy especially in case of a large external magnetic field. In addition, the magnetic damping effect was also discussed in the paper.

Influence of temperature and strain rate on the longitudinal compressive crashworthiness of 3D braided composite tubes and finite element analysis

2016 ◽  
Vol 26 (7) ◽  
pp. 1003-1027 ◽  
Author(s):  
Xianyan Wu ◽  
Qian Zhang ◽  
Bohong Gu ◽  
Baozhong Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Strain Rate ◽  
Coupling Effect ◽  
Three Dimensional ◽  
Composite Tubes ◽  
Element Analysis ◽  
Impact Compression ◽  
Mechanical Coupling ◽  
The Impact

This article reports the longitudinal compressive crashworthiness of three-dimensional four-step circular braided carbon/epoxy composite tubes at temperatures of 23, −50, and −100℃ under strain rate ranging from 340 to 760/s both experimentally and finite element analysis. The experimental results showed that the compression strength, stiffness, and specific energy absorption increased with the decrease in temperature and with the increase in strain rate. It also showed that, the compressive damage morphologies were sensitive to the change in temperature and strain rate. A coupled thermal-mechanical numerical analysis was conducted to find the thermo/mechanical coupling effect on the compressive crashworthiness of the three-dimensional composite tube. The temperature distributions in the braided preform and the resin during the impact compression were also calculated through finite element analysis. From the finite element analysis results, the inelastic heat generation was seen to be more in the preform than the matrix and its distribution and accumulation led to the damage progress along the loading direction.

Fuzzy Vibration Control of Flexible Solar Panel Using Piezoelectric Stack

2011 ◽  
Vol 50-51 ◽  
pp. 214-218 ◽  
Author(s):  
Rui Xu ◽  
Dong Xu Li ◽  
Jian Ping Jiang
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Logic Controller ◽  
Bending Moment ◽  
Finite Element Method Simulation ◽  
Positive Control ◽  
Smart Structure ◽  
Solar Panel ◽  
The Finite Element Method ◽  
Dynamical Equations ◽  
Logic Control

To effectively suppress vibrations of the flexible solar panel, the fuzzy logic control with piezoelectric smart structure is studied. The bending moment induced in the solar panel by the PZT stack actuator is formulated. The dynamical equations of the solar panel are derived. A fuzzy logic controller which uses universal fuzzy sets is designed. Considered the characteristic of the PZT stack, only positive control voltages were loaded to it. The finite element method simulation results demonstrate that the fuzzy logic controller can suppress the vibrations of the flexible spacecraft solar panel effectively.

Chemical Shrinkage and Residual Stresses in Laminated Composites during Cure

2005 ◽  
Vol 297-300 ◽  
pp. 2870-2875
Author(s):  
Soo Yong Lee ◽  
Jung Sun Park
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Composite Structures ◽  
Laminated Composites ◽  
Shear Deformation Theory ◽  
Chemical Shrinkage ◽  
Element Analysis ◽  
Finite Element Program ◽  
Residual Strains ◽  
Degenerated Shell Element

The residual stress that occurs in fiber-reinforced thermosetting composite materials during cure is one of the severe factors that can deteriorate the performance of composite structures. To investigate residual stresses occurring in laminated composites during cure, an incremental viscoelastic constitutive equation is derived as a function of temperature, degree of cure and chemical shrinkage. A finite element program is developed on the basis of a 3-D degenerated shell element and the first order shear deformation theory. Experiments were performed to measure the coefficients of chemical shrinkage of the Hercules AS4/3501-6 composite during cure. Residual strains were measured using strain gages during cure and compared with the results of finite element analysis. Good agreement is found between numerical and experimental results. It is found that the chemical shrinkage seriously affects the residual strains of the composite during cure.

Finite element analysis of frictionless contact problems using fuzzy control approach

2015 ◽  
Vol 32 (3) ◽  
pp. 585-606 ◽  
Author(s):  
F Massa ◽  
H Do ◽  
O Cazier ◽  
T Tison ◽  
B Lallemand
Keyword(s):  
Finite Element ◽  
Fuzzy Logic ◽  
Contact Problem ◽  
Fuzzy Logic Controller ◽  
Computational Time ◽  
Contact Method ◽  
Normal Contact ◽  
Content Type ◽  
Frictionless Contact ◽  
Non Linear

Purpose – The purpose of this paper is to present a new way to solve numerically a mechanical frictionless contact problem within a context of multiple sampling, frequently used to design robust structures. Design/methodology/approach – This paper proposes to integrate a control-based approach, currently used in automation domain, for the solving of non-linear mechanical problem. More precisely, a fuzzy logic controller is designed to create a link between the normal gaps identified between the bodies and the normal contact pressures applied at the interface. Findings – With this new strategy, the initial non-linear problem can be decomposed into a set of reduced linear problems solved using the finite element method. A projection built from the modal bases of each component in contact is considered to reduce computational time. Moreover, the proposed numerical applications highlight an interesting compromise between computation time and precision of contact data. Research limitations/implications – Currently, the proposed Fuzzy Logic Controller for Contact method has been developed for a frictionless contact problem in the case of 2D numerical applications. Therefore, as obtained results are very interesting, it will be possible to expand on these works in a future works for more complex problems including friction, 3D model and transient dynamic responses by adding other controllers. Originality/value – In conclusion, this paper highlights the interest of studying a contact problem by considering automation approaches and defines the basis of future multidisciplinary works.

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