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    18 July 2007, Volume 28 Issue 7
    Articles
    Green quasifunction method for vibration of simply-supported thin polygonic plates on Pasternak foundation
    YUAN Hong;LI Shan-qing;LIU Ren-huai
    2007, 28(7):  847-853 .  doi:10.1007/s10483-007-0701-y
    Abstract ( 1355 )   PDF (180KB) ( 628 )  
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    A new numerical method---Green quasifunction is proposed. The idea of Green quasifunction method is clarified in detail by considering a vibration problem of simply-supported thin polygonic plates on Pasternak foundation. A
    Green quasifunction is established by using the fundamental solution and boundary equation of the problem. This function satisfies the homogeneous boundary condition of the problem. The mode shape differential equation of the vibration problem of simply-supported thin plates on Pasternak foundation is reduced to two simultaneous Fredholm integral equations of the second kind by Green formula. There are multiple choices for the normalized boundary equation. Based on a chosen normalized boundary equation, a new normalized boundary equation can be established such that the irregularity of the kernel of integral equations is overcome. Finally, natural frequency is obtained by the condition that there exists a nontrivial solution in the numerically discrete algebraic equations derived from the integral equations. Numerical results show high accuracy of the Green quasifunction method.
    Analytical solution for functionally graded anisotropic cantilever beam subjected to linearly distributed load
    HUANG De-jin;DING Hao-jiang;CHEN Wei-qiu
    2007, 28(7):  855-860 .  doi:10.1007/s10483-007-0702-1
    Abstract ( 1184 )   PDF (266KB) ( 801 )  
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    The bending problem of a functionally graded anisotropic cantilever beam subjected to a linearly distributed load is investigated. The analysis is based on the exact elasticity equations for the plane stress problem. The stress function is introduced and assumed in the form of a polynomial of the longitudinal coordinate. The expressions for stress components are then educed from the stress function by simple differentiation. The stress function is determined from the compatibility equation as well as the boundary conditions by a skilful deduction. The analytical solution is compared with FEM calculation, indicating a good agreement.
    Forced vibration and special effects of revolution shells in turning point range
    ZHANG Zhi-liang;CHENG Chang-jun
    2007, 28(7):  861-872 .  doi:10.1007/s10483-007-0703-x
    Abstract ( 1374 )   PDF (335KB) ( 555 )  
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    The forced vibration in the turning point frequency range of a truncated revolution shell subject to a membrane drive or a bending drive at its small end or large end is studied by applying the uniformly valid solutions obtained in a previous paper. The vibration shows a strong coupling between the membrane and bending solutions: either the membrane drive or the bending drive causes motions of both the membrane type and bending type. Three interesting effects characteristic of the forced vibration emerge from the coupling nature: the non-bending effect, the inner-quiescent effect and the inner-membrane-motion-and-outer-bending-motion effect. These effects may have potential applications in engineering.
    Lateral resonances in initial stressed 1-3 piezocomposites
    ZHANG Hong-yan;SHEN Ya-peng;YIN Guan-sheng
    2007, 28(7):  873-881 .  doi:10.1007/s10483-007-0704-x
    Abstract ( 1458 )   PDF (352KB) ( 499 )  
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    A theoretical analysis of the lateral resonances in 1-3 piezocomposites with poling initial stress is conducted using the Bloch wave theory. Based on the linear piezoelectricity theory, theoretical formulations that include initial stress for the propagation of acoustic plane waves are made. Numerical calculations are performed to study the effects of the initial stress on the lateral mode frequencies and the stop band. It is found that lateral mode frequencies increase with the piezoelectricity of the piezocomposites, but decrease with the poling initial stress. The influence of the initial shear stress on the lateral mode frequencies is minimal, and can thus be neglected.
    Kink wave determined by parabola solution of a nonlinear ordinary differential equation
    LI Ji-bin;LI Ming;NA Jing
    2007, 28(7):  883-892 .  doi:10.1007/s10483-007-0705-z
    Abstract ( 1445 )   PDF (176KB) ( 487 )  
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    By finding a parabola solution connecting two equilibrium points of a planar dynamical system, the existence of the kink wave solution for 6 classes of nonlinear wave equations is shown. Some exact explicit parametric representations of kink wave solutions are given. Explicit parameter conditions to guarantee the existence of kink wave solutions are determined.
    Control of chaotic oscillations of a satellite
    Alexey Bobtsov;Nikolay Nikolaev;Olga Slita
    2007, 28(7):  893-900 .  doi:10.1007/s10483-007-0706-z
    Abstract ( 1324 )   PDF (314KB) ( 549 )  
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    Analytical conditions and practical methods of their realization are proposed to solve a problem of a command signal tracking for a nonlinear disturbed system. Nonlinear disturbed plants consisting of linear dynamic block and nonlinear block in feedback are considered. Nonlinear part of the plant and disturbance are unknown and bounded. The paper illustrates a possibility of applications of proposed algorithms to control libration angle of satellite.
    Weighted Cebysev-Ostrowski type inequalities
    Arif Rafiq;Nazir Ahmad Mir;Farooq Ahmad
    2007, 28(7):  901-906 .  doi:10.1007/s10483-007-0707-z
    Abstract ( 1144 )   PDF (116KB) ( 523 )  
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    In account of the famous Cebysev inequality, a rich theory has appeared in the literature. We establish some new weighted Cebysev type integral inequalities. Our proofs are of independent interest and provide new estimates on these types of inequalities.
    Physical factors of primary jet vectoring control using synthetic jet actuators
    XIA Zhi-xun;LUO Zhen-bing
    2007, 28(7):  907-920 .  doi:10.1007/s10483-007-0708-z
    Abstract ( 1156 )   PDF (1658KB) ( 533 )  
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    A primary jet vectoring using synthetic jet actuators with different exit configurations was investigated, and the main physical factors influencing jet vectoring were analyzed and summarized. The physical factors of the pressure difference, the location and area of the lower pressure region, the component of the synthetic jet momentum and the entrainment ratio of the synthetic jet flow to primary jet flow directly control the vectoring force and the vectoring angle. Three characteristic parameters of the synthetic jet contribute to the pressure difference and the area of the lower pressure region Boththe extension step and slope angle of the actuator exit have functions of regulating the location of the lower pressure region, the area of the lower pressure region, and the entrainment ratio of the synthetic jet flow to primary jet flow. The slope angle of the actuator exit has additional functions of regulating the component of the synthetic jet momentum. Based upon analyzing the physical factors of jet vectoring control with synthetic jets, the source variables of the physical factors were established. A preparatory control model of jet vectoring using synthetic jet actuator was presented, and it has the benefit of explaining the efficiency of jet vectoring using synthetic jet actuator with source variables at different values, and it indicates the optimal actuator is taking full advantage of the regulating function.
    Numerical study of dynamic phase transitions in shock tube
    WANG Ping;TANG Shao-qiang
    2007, 28(7):  921-929 .  doi:10.1007/s10483-007-0709-z
    Abstract ( 1317 )   PDF (938KB) ( 523 )  
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    Shock tube problem of a van der Waals fluid with a relaxation model was investigated. In the limit of relaxation parameter tending towards zero, this model yields a specific Riemann solver. Relaxing and relaxed schemes were derived. For an incident shock in a fixed tube, numerical simulations show convergence toward the Riemann solution in one space dimension. Impact of parameters was studied theoretically and numerically. For certain initial shock profiles, nonclassical reflecting wave was observed. In two space dimensions, the effect of curved wave fronts was studied, and some interesting wave patterns were exposed.
    Unconventional Hamilton-type variational principles for nonlinear elastodynamics of orthogonal cable-net structures
    LI Wei-hua;LUO En;HUANG Wei-jiang
    2007, 28(7):  931-942 .  doi:10.1007/s10483-007-0710-x
    Abstract ( 1383 )   PDF (205KB) ( 548 )  
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    According to the basic idea of classical yin-yang complementarity and modem dual-complementarity, in a simple and unified new way proposed by Luo, the unconventional Hamilton-type variational principles for geometrically nonlinear elastodynamics of orthogonal cable-net structures are established systematically, which can fully characterize the initial-boundary-value problem of this kind of dynamics. An important integral relation is made, which can be considered as the generalized principle of virtual work for geometrically nonlinear dynamics of orthogonal cable-net structures in mechanics. Based on such relationship, it is possible not only to obtain the principle of virtual work for geometrically nonlinear dynamics of orthogonal cable-net structures, but also to derive systematically the complementary functionals for five-field, four-field, three-field and two-field unconventional Hamilton-type variational principles, and the functional for the unconventional Hamilton-type variational principle in phase space and the potential energy functional for one-field unconventional Hamilton-type variational principle for geometrically nonlinear elastodynamics of orthogonal cable-net structures by the generalized Legendre transformation given in this paper. Furthermore, the intrinsic relationship among various principles can be explained clearly with this approach.
    Three-point explicit compact difference scheme with arbitrary order
    of accuracy and its application in CFD
    LIN Jian-guo;XIE Zhi-hua;ZHOU Jun-tao
    2007, 28(7):  943-953 .  doi:10.1007/s10483-007-0711-x
    Abstract ( 1369 )   PDF (640KB) ( 688 )  
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    Based on the successive iteration in the Taylor series expansion method, a three-point explicit compact difference scheme with arbitrary order of accuracy is derived in this paper. Numerical characteristics of the scheme are studied by the Fourier analysis. Unlike the conventional compact difference schemes which need to solve the equation to obtain the unknown derivatives in each node, the proposed scheme is explicit and can achieve arbitrary order of accuracy in space. Application examples for the convection-diffusion problem with a sharp front gradient and the typical lid-driven cavity flow are given. It is found that the proposed compact scheme is not only simple to implement and economical to use, but also is effective to simulate the convection-dominated problem and obtain high-order accurate solution in coarse grid systems.
    Markovian risk process
    WANG Han-xing;YAN Yun-zhi;ZHAO Fei;FANG Da-fan
    2007, 28(7):  955-962 .  doi:10.1007/s10483-007-0712-y
    Abstract ( 1205 )   PDF (163KB) ( 524 )  
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    A Markovian risk process is considered in this paper, which is the generalization of the classical risk model.It is proper that a risk process with large claims is modelled as the Markovian risk model.In such a model, the occurrence of claims is described by a point process {N(t)}t>0 with N(t) being the number of jumps during the interval (0,t] for a Markov jump process. The ruin probability Ψ(u) of a company facing such a risk model is mainly studied. An integral equation satisfied by the ruin probability function Ψ(u) is obtained and the bounds for the convergence rate of the ruin probability Ψ(u) are given by using a generalized renewal technique developed in the paper.
    A kind of bivariate spline space over rectangular partition and pure bending of thin plate
    WANG Ren-hong;CHANG Jin-cai
    2007, 28(7):  963-971 .  doi:10.1007/s10483-007-0713-y
    Abstract ( 1719 )   PDF (396KB) ( 692 )  
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    The mechanical background of the bivariate spline space of degree 2 and smoothness 1 on rectangular partition is presented constructively. Making use of mechanical analysis method, by acting couples along the interior edges with suitable evaluations, the deflection surface is divided into piecewise form, therefore, the relation between a class of bivariate splines on rectangular partition and the pure bending of thin plate is established.In addition, the interpretation of smoothing cofactor and conformality condition from the mechanical point of view is given.Furthermore, by introducing twisting moments, the mechanical background of any spline belong to the above space is set up.
    Alternating segment explicit-implicit scheme for nonlinear third-order KdV equation
    QU Fu-li;WANG Wen-qia
    2007, 28(7):  973-980 .  doi:10.1007/s10483-007-0714-y
    Abstract ( 1407 )   PDF (928KB) ( 970 )  
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    A group of asymmetric difference schemes to approach the Korteweg-de Vries (KdV) equation is given here. According to such schemes, the full explicit difference scheme and the full implicit one, an alternating segment explicit-implicit difference scheme for solving the KdV equation is constructed. The scheme is linear unconditionally stable by the analysis of linearization procedure, and is used directly on the parallel computer. The numerical experiments show that the method has high accuracy.
    On a class of quasilinear Schrödinger equations
    SHU Ji;ZHANG Jian
    2007, 28(7):  981-986 .  doi:10.1007/s10483-007-0715-y
    Abstract ( 1320 )   PDF (129KB) ( 483 )  
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    A type of quasilinear Schrodinger equations in two space dimensions which describe attractive Bose-Einstein condensates in physics is discussed.By establishing the property of the equation and applying the energy method, the blowup of solutions to the equation are proved under certain conditions. At the same time, by the variational method, a sufficient condition of global existence which is related to the ground state of a classical elliptic equation is obtained.
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