active control of nonlinear forced vibration in a flexibl

24
This article was downloaded by: [Monash University Library] On: 07 December 2014, At: 06:12 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK Mechanics of Advanced Materials and Structures Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/umcm20 Active control of nonlinear forced vibration in a flexible beam using piezoelectric material Feng-Ming Li a , Guo Yao b & Yimin Zhang b a College of Mechanical Engineering, Beijing University of Technology, Beijing 100124, China b School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819, China Accepted author version posted online: 18 Nov 2014. To cite this article: Feng-Ming Li, Guo Yao & Yimin Zhang (2014): Active control of nonlinear forced vibration in a flexible beam using piezoelectric material, Mechanics of Advanced Materials and Structures, DOI: 10.1080/15376494.2014.981613 To link to this article: http://dx.doi.org/10.1080/15376494.2014.981613 Disclaimer: This is a version of an unedited manuscript that has been accepted for publication. As a service to authors and researchers we are providing this version of the accepted manuscript (AM). Copyediting, typesetting, and review of the resulting proof will be undertaken on this manuscript before final publication of the Version of Record (VoR). During production and pre-press, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal relate to this version also. PLEASE SCROLL DOWN FOR ARTICLE Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content. This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http:// www.tandfonline.com/page/terms-and-conditions

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  • This article was downloaded by: [Monash University Library]On: 07 December 2014, At: 06:12Publisher: Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House,37-41 Mortimer Street, London W1T 3JH, UK

    Mechanics of Advanced Materials and StructuresPublication details, including instructions for authors and subscription information:http://www.tandfonline.com/loi/umcm20

    Active control of nonlinear forced vibration in aflexible beam using piezoelectric materialFeng-Ming Lia, Guo Yaob & Yimin Zhangba College of Mechanical Engineering, Beijing University of Technology, Beijing 100124, Chinab School of Mechanical Engineering and Automation, Northeastern University, Shenyang110819, ChinaAccepted author version posted online: 18 Nov 2014.

    To cite this article: Feng-Ming Li, Guo Yao & Yimin Zhang (2014): Active control of nonlinear forced vibration in a flexiblebeam using piezoelectric material, Mechanics of Advanced Materials and Structures, DOI: 10.1080/15376494.2014.981613

    To link to this article: http://dx.doi.org/10.1080/15376494.2014.981613

    Disclaimer: This is a version of an unedited manuscript that has been accepted for publication. As a serviceto authors and researchers we are providing this version of the accepted manuscript (AM). Copyediting,typesetting, and review of the resulting proof will be undertaken on this manuscript before final publication ofthe Version of Record (VoR). During production and pre-press, errors may be discovered which could affect thecontent, and all legal disclaimers that apply to the journal relate to this version also.

    PLEASE SCROLL DOWN FOR ARTICLE

    Taylor & Francis makes every effort to ensure the accuracy of all the information (the Content) containedin the publications on our platform. However, Taylor & Francis, our agents, and our licensors make norepresentations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of theContent. Any opinions and views expressed in this publication are the opinions and views of the authors, andare not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon andshould be independently verified with primary sources of information. Taylor and Francis shall not be liable forany losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoeveror howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use ofthe Content.

    This article may be used for research, teaching, and private study purposes. Any substantial or systematicreproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in anyform to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions

    http://www.tandfonline.com/loi/umcm20http://www.tandfonline.com/action/showCitFormats?doi=10.1080/15376494.2014.981613http://dx.doi.org/10.1080/15376494.2014.981613http://www.tandfonline.com/page/terms-and-conditionshttp://www.tandfonline.com/page/terms-and-conditions
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    Active control of nonlinear forced vibration in a flexible beam using piezoelectric material

    Feng-Ming Li 1

    , Guo Yao 2, Yimin Zhang

    2

    1. College of Mechanical Engineering, Beijing University of Technology, Beijing 100124, China

    2. School of Mechanical Engineering and Automation, Northeastern University, Shenyang

    110819, China

    Abstract: Geometric nonlinearities of the beam and piezoelectric patch are considered. Velocity

    feedback control algorithm is implemented applying piezoelectric materials. The equation of

    motion of the system is established using Hamiltons principle. The effects of control gains on

    primary resonance properties of the beam are studied. It is observed that with the amplitude of

    external excitation increasing, the amplitude of resonance curve increases. The velocity feedback

    control can improve unstable resonance of the beam. When the control gain is increased to a

    certain value, the unstable regions in the resonance and amplitude-frequency curves disappear.

    Key words: Beam; piezoelectric material; nonlinear vibration; active control; multiple-scales

    method.

    Corresponding author. Tel.: +86 10 67392704.

    Email address: [email protected] (F.-M. Li). Dr., Professor of Beijing University of Technology, Beijing, China.

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    1 Introduction

    The nonlinear forced vibrations of the mechanical structures are commonly seen in many

    mechanical applications and the nonlinear dynamic characteristics of these structural systems are

    focused by numerous researchers. Maccari [1] studied the time-delayed feedback control of the

    primary resonance of a cantilevered beam. By applying the asymptotic perturbation method, the

    amplitude-frequency relation of the system was obtained and the effects of the time delay and

    feedback control gains on the resonance of the beam were studied. El-Bassiouny [2] studied the

    resonances and control of a cantilevered beam by using the multiple-scales method and found

    that the quantic velocity feedback control can stabilize the unstable amplitude. Yao and Li [3]

    studied the bifurcation and chaotic motions of the two-dimensional composite laminated plates in

    subsonic flow. They obtained the critical instability velocities of the plate by computing a

    generalized double integral. Li and Liu [4] studied the nonlinear vibration and active control of a

    simply supported beam subjected to axial harmonic excitation. The effects of the velocity

    feedback control gains on the stability of the beam were discussed.

    Based on the Euler-Bernoulli beam theory, Rafiee et al. [5] studied the nonlinear free and

    forced vibration of a nanotube by using the multiple-scales method. The effects of the spring

    constant of the elastic foundation and the aspect ratio of the nanotube on the nonlinear oscillation

    properties of the system were discussed. Shooshtari and Rafiee [6] investigated the primary and

    secondary resonances of a symmetric functionally graded beam by using the multiple-scales

    method. The amplitude-frequency relation of the system was obtained and the effects of the

    system parameters on the resonance properties of the beam were studied. Emam and Nayfeh [7]

    studied the nonlinear vibration of a clamped beam subjected to uniform axial load and transverse

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    harmonic excitation. The bifurcation and chaos of the buckled beam were analysed.

    The nonlinear vibration and its control of the plates and shells were also extensively studied.

    Abe et al. [8] investigated the primary resonance of a composite rectangular plate by using the

    multiple-scales method. Zhang [9] analysed the chaotic motion of a composite plate subjected to

    parametric excitation. Tang and Chen [10] researched the nonlinear vibration of a plate

    considering the internal resonance. Singha and Daripa [11] studied the nonlinear forced vibration

    of a plate under transverse harmonic excitation and in-plane periodical load. Amabili [12-14]

    conducted a series of relevant investigations in the nonlinear vibration of the cylindrical shells.

    Li and Yao [15] studied the 1/3 subharmonic resonance of a composite cylindrical shell subjected

    to subsonic airflow. The necessary condition for the 1/3 subharmonic resonance of the shell was

    obtained.

    From the literatures mentioned above, it can be seen that the unstable nonlinear resonances

    of the flexible structures are common in the mechanical engineering. So it is necessary to

    investigate the characteristics of the nonlinear resonance and to search for appropriate control

    algorithm to stabilize the nonlinear vibration system. In the present study, the equation of motion

    of the beam bonded with piezoelectric patch is established using the Hamiltons principle. The

    nonlinear forced vibration of the beam is studied by applying the multiple-scales method. The

    velocity feedback control algorithm is adopted to stabilize the unstable resonance and the applied

    external control voltages on the piezoelectric actuators are presented to show the feasibility of

    the active control strategy.

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    2 Structural equation of motion

    The simply supported beam with rectangular cross section as shown in Fig. 1 is considered.

    The piezoelectric patch is well bonded on the surface of the beam. Fig. 1 shows the Cartesian

    coordinates, in which the x-axis is established at the neutral surface of the base beam and along

    the axial direction. The harmonic force F(t) = F0cos(t) is applied transversely at the position x

    = xF of the base beam. In the study, the effects of the axial deformation on the transverse

    displacement of the beam are neglected.

    The material of the base beam is homogenous and isotropic. The normal stress and normal

    strain in the beam are expressed as

    xx E , 2

    2

    2

    )(2

    1

    x

    w

    x

    wzx

    , (1)

    where w is the transverse deflection of the beam, and x, x and E are the normal stress, normal

    strain and elastic modulus, respectively.

    The piezoelectric material is transversely isotropic and the polarization direction is in the

    z-axis. The constitutive equation of the piezoelectric material is expressed as

    z

    p

    x

    p

    x Eec 3111 , zp

    xz EeD 3331 , (2)

    where px and p

    x are the normal stress and normal strain of the piezoelectric material, c11, e31

    and 33 are the elastic constant, piezoelectric constant and dielectric constant of the piezoelectric

    material, Dz is the electric displacement in the z direction, and Ez = V0(t)/hp is the electric

    intensity, in which V0 is the external applied voltage on the piezoelectric layer and hp is the

    thickness of the piezoelectric layer. Since the piezoelectric material is well bonded on the surface

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    of the base beam and the influences of the axial deformation on the transverse displacement of

    the beam are neglected, it is assumed that the normal strain px of the piezoelectric material is

    the same as that of the base beam, i.e. the deformations between the piezoelectric material and

    the base beam are consistent.

    The kinetic and potential energies of the total structure can be obtained as [4]

    L

    xt

    wmT

    0

    2d)(2

    1, (3a)

    pp V

    zzV

    xpx

    Vxx VEDVVU d

    2

    1d

    2

    1d

    2

    1

    LLL

    xx

    w

    x

    wax

    x

    wVax

    x

    wa

    0

    2

    2

    2

    30 2

    2

    020

    2

    2

    2

    1 d)(dd)(

    206

    0

    45

    0

    204 d)(d)( Vax

    x

    wax

    x

    wVa

    LL

    , (3b)

    where L is the length of the base beam, m = S +pSp is the mass per unit length of the base beam

    and piezoelectric material, and p are the mass densities of the base beam and piezoelectric

    material, S and Sp are the section areas of the base beam and piezoelectric patch, and the

    coefficients can be expressed as

    24

    )364( 22113

    1

    hhhhbhcEbha

    ppp ,

    2

    )2(312

    hhbea

    p ,

    4

    )(113

    hhhbca

    pp ,

    2

    314

    bea ,

    8

    11

    5

    pbhcEbha

    ,

    ph

    bLa

    2

    336

    , (4)

    where h is the thickness of the base beam and b is the width of the base beam and piezoelectric

    patch.

    The work done by the external applied force F is written as

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    FxxFFwW . (5)

    Hamiltons principle is written as

    0dd)(2

    1

    2

    1

    tWtUT Ft

    t

    t

    t , (6)

    where denotes the first variation, and t1 and t2 are the integration time limits.

    The first order expansion of the transverse displacement of the simply supported beam is

    considered. So the displacement w can be expressed as

    L

    xtWtxw

    sin)(),( , (7)

    where W(t) is the displacement amplitude, i.e. the generalized coordinates.

    Substituting Eqs. (3), (5) and (7) into Eq. (6), and performing the variation operation in

    terms of W, the following nonlinear equation of motion of the whole structure can be obtained:

    tFWaWaWVaWaVat

    W cos

    d

    d1

    3

    11

    2

    10098072

    2

    , (8)

    where 2

    27

    4

    mL

    aa

    ,

    4

    4

    18

    2

    mL

    aa

    ,

    2

    2

    49

    2

    mL

    aa

    ,

    4

    3

    310

    4

    mL

    aa

    ,

    4

    4

    511

    3

    mL

    aa

    , and

    L

    x

    mL

    FF F

    sin

    2 01 .

    One can observe that the second and fourth terms in Eq. (8) are the electromechanical

    coupling terms which relate the external applied voltage to the structural deformation, and

    indicate that the external applied voltage will affect the nonlinear dynamic properties of the

    structural system. Furthermore, it can be seen that the structural vibration equation is cubic

    nonlinear.

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    3 Controller design

    The piezoelectric material can be activated by appropriate external control voltage to obtain

    active damping and improve structural vibration stability. To achieve this aim, a velocity

    feedback control strategy can be applied. The velocity at position x0 of the beam is measured by

    a velocity sensor and fed back to the controller. The controller calculates control voltage with

    velocity feedback control method, and exerts the voltage to the piezoelectric actuator patch to

    produce control force. The control voltage exerted to the piezoelectric actuator is proportional to

    the velocity at the position x0, and can be expressed as

    t

    W

    L

    xK

    t

    txwKV

    d

    dsin

    d

    ),(d 000

    , (9)

    where K is the feedback control gain for the piezoelectric actuator.

    Substituting Eq. (9) into Eq. (8), and combining with Eq. (7), the equation of motion is

    changed to the following cubic nonlinear equation with active damping

    tFWaWat

    WWaWa

    t

    Wc

    t

    Wp cos

    d

    d

    d

    d

    d

    d1

    3

    11

    2

    101282

    2

    , (10)

    where L

    xKacp

    07 sin

    and

    L

    xKaa 0912 sin

    .

    The second term in Eq. (10) is the active damping force due to the velocity feedback, and

    the coefficient cp is the active damping coefficient which is related to the feedback control gain K.

    We can see from Eq. (10) that by applying the piezoelectric material and velocity feedback

    control, the active damping can be produced to influence the structural dynamic response. By

    actively adjusting the feedback control gain K, the structural dynamic properties will be changed.

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    4 Active control of nonlinear vibration

    The active control for the nonlinear vibration of the beam will be investigated by solving

    the steady response of the equation of motion, i.e. Eq. (10). By defining 82

    0 a , Eq. (10) can

    be changed to the following form:

    tFWaWat

    WWaW

    t

    Wc

    t

    Wp cos

    d

    d

    d

    d

    d

    d1

    3

    11

    2

    1012

    2

    02

    2

    . (11)

    Defining the following non-dimensional variables:

    h

    WW ,

    1

    00

    , tt 1 ,

    1

    , (12)

    where 4

    2

    1mL

    EI is the first natural frequency of the base beam, in which

    12

    3bhI is the

    moment of inertia for the cross section of the base beam. Substituting the above non-dimensional

    variables into Eq. (11) results in the following dimensionless equation of motion:

    tFWWt

    WWW

    t

    Wc

    t

    W p cos

    d

    d

    d

    d

    d

    d 3220

    1

    2

    2

    , (13)

    where , and are the dimensionless coefficients and expressed as: 1

    12

    ha

    , 2

    1

    10

    ha

    and 2

    1

    2

    11

    ha

    , and 2

    1

    1h

    FF is the dimensionless force amplitude. For the sake of the

    convenience of writing, the symbol over the non-dimensional variables will be omitted in

    what follows.

    The method of multiple-scales [16, 17] will be used to solve the nonlinear equation of

    motion. So the following substitutions are made:

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    ccp

    1

    , , , , fF , (14)

    where is a small dimensionless perturbation parameter. Then Eq. (13) can be changed to

    tfWWt

    WWW

    t

    Wc

    t

    W cos

    d

    d

    d

    d

    d

    d 32202

    2

    . (15)

    Suppose the solution of Eq. (15) can be expressed as the following form:

    ),,,(),,,(),,,(),( 21022

    21012100 TTTWTTTWTTTWtW , (16)

    where Tn = nt (n = 0, 1, 2, ), and the first two time scales are taken. T0 = t is the fast varying

    time scale and T1 = t is the slowly varying time scale. So the time derivatives are written as

    follows:

    10

    10d

    dDD

    TTt ,

    10

    2

    0

    10

    2

    2

    0

    2

    2

    2

    22d

    dDDD

    TTTt . (17)

    In this paper, the nonlinear primary resonance is studied. So we set

    220 , (18)

    where is the tuning parameter describing the approaching degree between and .

    Substitution of Eqs. (16)-(18) into Eq. (15), after equating coefficients of same power of ,

    results in the following differential equations:

    002

    0

    2

    0 WWD , (19)

    )cos(2 03

    0

    2

    0000000101

    2

    1

    2

    0 TfWWWDWWcDWDDWWD . (20)

    The complex solution of Eq. (19) can be obtained as

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    )iexp()()iexp()( 01010 TTaTTaW , (21)

    where a is the complex conjugate of a.

    Substituting Eq. (21) into Eq. (20) yields the following equation:

    )i2exp()i()iexp()2

    13ii2( 0

    22

    0

    2

    1

    2

    1

    2

    0 TaaTfaaaacaWWD

    ccaaTa )i3exp( 03 , (22)

    where a is the derivative of a with respect to T1, and cc indicates the complex conjugate part at

    the right hand side of Eq. (22). Eliminating the secular terms in Eq. (22) leads to

    02

    13ii2 2 faaaaca . (23)

    In order to solve function a, one writes a in exponential function form as follows:

    )iexp(2

    1Aa , (24)

    where A and are all real function of T1. Substituting Eq. (24) into Eq. (23) and dividing the real

    parts from the imaginary parts yield

    sin2

    1

    2

    1fcAA

    , (25)

    cos228

    3 2

    A

    fA . (26)

    By letting 0 A and substituting

    22

    0 in Eqs. (25) and (26), the stationary

    solution can be obtained as

    0])[()(2

    3

    16

    9 2222222

    0

    22

    0426

    fAcAA

    . (27)

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    The above formulation is called as the resonant curve equation which relates the displacement

    amplitude A with the force amplitude f and frequency . From Eq. (27) one can see that the

    feedback control gain K (which is related to the damping coefficient c) has effects on the

    structural dynamic response.

    When the active control is implemented, the external applied voltage amplitude can be

    obtained by combining Eqs. (9), (21) and (24) as

    L

    xKAhV 010 sin

    . (28)

    Next, the influences of the different parameters on the structural primary resonant curve

    characteristics will be analyzed.

    5 Example and discussions

    A simply supported beam with geometric nonlinearity bonded with piezoelectric layer

    subjected to external force F is shown in Fig. 1. The parameters for the base beam and

    piezoelectric material are shown in Table 1. The velocity sensor is located at the middle position

    of the beam, i.e. x0 = L/2. The external force F is assumed to be also applied at the middle

    position of the beam, i.e. xF = L/2.

    5.1 Validity of the present methodology

    In this section, the validity of the present study is verified by comparing the amplitude-frequency

    curve obtained from Eq. (27) with that by numerical simulation. In numerical calculation, the

    time-domain responses of the beam under certain excitation frequencies are computed using the

    4th order Runge-Kutta method. The response amplitudes corresponding to different excitation

    frequencies are extracted from the time-domain responses. Fig. 2 shows the comparison of the

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    amplitude-frequency response at the center of the beam obtained by this method with that by the

    numerical calculation. In Fig. 2 the solid curve represents the stable response of the beam, the

    dashed line denotes the unstable response, and the dots represent the vibration amplitude of the

    beam obtained from the numerical simulation. From Fig. 2 it can be seen that the

    amplitude-frequency curve obtained by the present method is in agreement with that from the

    numerical simulation, which verifies the validity of the present methodology.

    5.2 Nonlinear dynamic properties of the uncontrolled beam

    In this section, the nonlinear dynamic properties of the uncontrolled beam under harmonic

    external excitation are investigated. From Eq. (27), one can obtain the relation between the

    amplitude of the resonance displacement and the amplitude of the external excitation. For =

    1.2, it implies that the frequency of the external excitation is 1.2 times of the fundamental natural

    frequency of the beam with piezoelectric actuator. Fig. 3 shows the variations of the

    displacement amplitude A with the force amplitude f of the uncontrolled dynamic system. It can

    be seen in Fig. 3 that the displacement amplitude is a multi-valued function of the external force

    amplitude. This may lead to instability of the system. For example, with the force amplitude f

    increasing from 0, the amplitude of the displacement A increases continuously from 0. When f

    increases to 1.75, the displacement amplitude rapidly changes from 0.15 to 0.32 and then

    increases gradually. Similarly, when the non-dimensional amplitude of the external excitation f

    decreases from 6, the displacement amplitude A of the beam decreases continuously first and

    jumps suddenly from 0.27 to 0 when f decreases to 0. This is called the jump phenomenon. The

    discontinuous changes of the displacement amplitude with respect to the force amplitude may

    make damage to the structural system.

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    Fig. 4 shows the amplitude-force curves of the beam for different non-dimensional external

    excitation frequencies. It can be seen in Fig. 4 that when =1.1, the amplitude-force curve is a

    single-valued curve and the displacement amplitude of the beam increases with the external

    excitation amplitude increasing. When = 1.15 and = 1.2, the amplitude-force curves are

    multi-valued ones. For = 1.2, the interval of the external excitation amplitude for the

    multi-valued range of the steady state response is larger than that for = 1.15. Fig. 5 shows the

    amplitude-frequency curves of the beam under different force amplitudes. In Fig. 5, the solid

    lines represent the stable displacement amplitudes and the dashed lines represent the unstable

    amplitudes of the displacement. It can be seen in Fig. 5 that with the frequency of the external

    excitation increasing, the vibration amplitude increases first and then decreases. The beam

    exhibits the hardening-type nonlinearity and with the amplitude of the external excitation

    increasing, the vibration amplitude increases also and the frequency interval for the unstable

    region is prolonged.

    5.3 Active vibration control

    The effects of the velocity feedback control on the resonance curve and the

    amplitude-frequency relations of the beam are investigated. Fig. 6 shows the variations of the

    displacement amplitude A with the force amplitude f under different feedback control gains. In

    the simulation, the frequency of the external excitation is chosen as = 1.2. It can be seen in Fig.

    6 that with the velocity feedback control gain increasing, the interval for the unstable resonance

    amplitude of the beam is reduced. When K is increased to 1000, the displacement amplitude is a

    single-valued function of the force amplitude. In such situation, the jump phenomenon of the

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    displacement amplitude with respect to the amplitude of the external force will disappear.

    Fig. 7 shows the external applied control voltage amplitudes with respect to the force

    amplitude f for different feedback control gains when = 1.2. It can be seen that with the

    feedback control gain increasing, the amplitude of the external applied voltage increases and the

    maximal amplitude of the control voltage is about 450V.

    Fig. 8 shows the amplitude-frequency curve of the beam with different feedback control

    gains when F0 = 2N. It can be seen in Fig. 8 that with the feedback control gain increasing, the

    amplitude of the resonance is decreased and the unstable region of the displacement amplitude is

    reduced. When K is increased to 1000, the unstable region of the vibration amplitude disappears.

    Fig. 9 represents the relations between the amplitudes of the applied external voltages and

    the frequency of the external force under different control gains. It can be seen in Fig. 9 that the

    peaks of the voltage amplitudes are about 420V for different control gains. But for K = 1000, the

    unstable region of the voltage amplitude will disappear. So the effects of the velocity feedback

    control gain on the stability of the applied external voltage can not be ignored.

    Fig. 10 shows the displacement-time histories at the center of the beam with and without

    velocity feedback control. It can be seen in Fig. 10 that for the uncontrolled beam, the maximum

    non-dimensional amplitude of the transverse vibration is about 0.5. When the feedback control

    gain K is chosen to be 1000, the maximum amplitude of the vibration is fallen to about 0.25,

    which implies that the velocity feedback control strategy can stabilize the nonlinear primary

    resonance of the beam.

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    6 Conclusions

    The nonlinear primary resonance properties and active control of a flexible beam under

    transverse harmonic excitation are studied. The equation of motion of the beam with geometric

    nonlinearity is established using the Hamiltons principle. The method of multiple-scales is

    applied to analyze the primary resonance properties of the beam, and velocity feedback control is

    used to stabilize the nonlinear vibration of the beam. From the theoretical analysis and numerical

    simulations, the following conclusions can be drawn:

    (1) For the uncontrolled system, the jump phenomenon appears. When the excitation frequency

    > 1, the vibration amplitude can be multi-valued function of the external excitation

    amplitude and the frequency interval for the unstable region is prolonged with the excitation

    frequency increasing.

    (2) The beam exhibits the hardening-type of nonlinearity. With the amplitude of the external

    excitation increasing, the amplitude of the steady state response increases and the

    hardening-type of nonlinearity is strengthened.

    (3) The velocity feedback control can stabilize the unstable primary resonance. With the

    feedback control gain increasing, the amplitude of the resonance curve and the peak values of

    the amplitude-frequency curves are reduced.

    (4) When the feedback control gain is increased to a certain value, the unstable region of the

    vibration amplitude will disappear, and the jump phenomenon is also avoided. The applied

    external voltages are in reasonable range, which shows the feasibility of the active control.

    Acknowledgements

    This research is supported by the National Basic Research Program of China (No.

    2011CB711100) and the National Natural Science Foundation of China (No. 11172084 and

    10672017).

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    References

    [1] Maccari A. Vibration control for the primary resonance of a cantilever beam by a time delay

    state feedback. Journal of Sound and Vibration, 2003, 259(2): 241-251.

    [2] El-Bassiouny A.F. Single-mode control and chaos of cantilever beam under primary and

    principal parametric excitations. Chaos, Solitons and Fractals, 2006, 30(5): 1098-1121.

    [3] Yao G., Li F.M. Chaotic motion of a composite laminated plate with geometric nonlinearity

    in subsonic flow. International Journal of Non-Linear Mechanics, 2013, 50: 81-90.

    [4] Li F.M., Liu C.C. Parametric vibration stability and active control of nonlinear beams.

    Applied Mathematics and Mechanics, 2012, 33(11): 1381-1392.

    [5] Rafiee M., Mareishi S., Mohammadi M. An investigation on primary resonance phenomena

    of elastic medium based single walled carbon nanotubes. Mechanics Research

    Communications, 2012, 44: 51-56.

    [6] Shooshtari A., Rafiee M. Nonlinear forced vibration analysis of clamped functionally graded

    beams. Acta Mechanica, 2011, 221(1-2): 23-38.

    [7] Emam S.A., Nayfeh A.H. On the nonlinear dynamics of a buckled beam subjected to a

    primary-resonance excitation. Nonlinear Dynamics, 2005, 35 (1): 1-17.

    [8] Abe A., Kobayashi Y., Yamada G. Two-mode response of simply supported, rectangular

    laminated plates. International Journal of Non-Linear Mechanics, 1998, 33(4): 675-690.

    [9] Zhang, W. Global and chaotic dynamics for a parametrically excited thin plate. Journal of

    Sound and Vibration, 2001, 239(5): 1013-1036.

    [10] Tang Y.Q., Chen L.Q. Nonlinear free transverse vibrations of in-plane moving plates:

    Without and with internal resonances. Journal of Sound and Vibration, 2011, 330(1):

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    110-126.

    [11] Singha M.K., Daripa R. Nonlinear vibration and dynamic stability analysis of composite

    plates. Journal of Sound and Vibration, 2009, 328(4-5): 541-554.

    [12] Amabili M. Nonlinear vibrations of angle-ply laminated circular cylindrical shells: Skewed

    modes. Composite Structures, 2012, 94(12): 3697-3709.

    [13] Amabili M. A comparison of shell theories for large-amplitude vibrations of circular

    cylindrical shells: Lagrangian approach. Journal of Sound and Vibration, 2003, 264 (5):

    1091-1125.

    [14] Amabili M. Nonlinear vibrations of circular cylindrical shells with different boundary

    conditions. AIAA Journal, 2003, 41(6): 1119-1130.

    [15] Li F.M., Yao G. 1/3 Subharmonic resonance of a nonlinear composite laminated cylindrical

    shell in subsonic air flow. Composite Structures, 2013, 100: 249-256.

    [16] Shen Y.J, Yang S.P., Xing H.J, Gao G.S. Primary resonance of Duffing oscillator with

    fractional-order derivative. Communications in Nonlinear Science and Numerical Simulation,

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    [17] Hu H., Dowell E.H., Virgin L.N. Resonances of a harmonically forced Duffing oscillator

    with time delay state feedback. Nonlinear Dynamics, 1998, 15(4): 311-327.

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    The list of the figures

    x

    z

    O

    F(t) Piezoelectric material

    Base beam

    Fig. 1 The schematic diagram of a beam with piezoelectric patch.

    xF

    0 0.5 1 1.5 20

    0.1

    0.2

    0.3

    0.4

    0.5

    0.6

    0.7

    w/h

    Fig. 2 Comparison of the amplitude-frequency curve of the beam calculated by the present method with that by

    numerical simulation (F0 = 5N, K = 1103).

    Present result

    Numerical simulation

    0 1 2 3 4 5 60

    0.05

    0.1

    0.15

    0.2

    0.25

    0.3

    0.35

    0.4

    f

    A

    Fig. 3 The variation of the displacement amplitude A with the force amplitude f when = 1.2.

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    0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50

    0.05

    0.1

    0.15

    0.2

    0.25

    0.3

    0.35

    0.4

    = 1.1

    = 1.15

    = 1.2

    f

    A

    Fig. 4 Amplitude-force curves of the beam for different external excitation frequencies.

    A

    F0 = 1N

    F0 = 2N

    F0 = 3N

    Fig. 5 Amplitude-frequency curves of the beam for different force amplitudes.

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    0 1 2 3 4 50

    0.05

    0.1

    0.15

    0.2

    0.25

    0.3

    0.35

    0.4

    f

    A

    K = 0

    K = 300

    K = 600

    K = 1000

    Fig. 6 The variations of the displacement amplitude A with the force amplitude f under different feedback

    control gains when = 1.2.

    0 1 2 3 4 50

    100

    200

    300

    400

    500

    V0(V

    )

    f

    K = 300

    K = 600

    K = 1000

    Fig. 7 The amplitudes of the applied external voltages with respect to the force amplitude f for different

    feedback control gains when = 1.2. Dow

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    A

    K = 300

    K = 600

    K = 1000

    Fig. 8 Amplitude-frequency curves of the beam with different feedback control gains when F0 = 2N.

    V0(V

    ) K = 300

    K = 600

    K = 1000

    Fig. 9 Variations of the amplitudes of the applied external voltages with the frequency of the external force for

    different feedback control gains when F0 = 2N.

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    0 50 100 150 200 250 300

    -0.4

    -0.2

    0

    0.2

    0.4

    0.6

    K = 0 K = 1000

    t

    w/h

    Fig. 10 Displacement-time histories at the center of the beam under different feedback control gains.

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    Table 1 The parameters for the base beam and piezoelectric material.

    Elastic constant Mass density Piezoelectric constant Length Width Thickness

    E or c11/(GPa) /(kgms2) e31/(Cm

    2) L/(m) b/(m) h/(m)

    Base beam(Al) 71 2710 0.5 0.01 0.005

    Piezoelectric layer(PZT-5H) 126 7500 6.50 0.5 0.01 0.001

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