three dimensional exact solution for the vibration of functionally graded rectangular plates abstract a three dimensional exact solution is presented for free and forced vibrations of simply supported functionally graded rectangular plates suitable displacement functions that identically satisfy boundary conditions are used to reduce equations governing steady state vibrations of a plate to a set of coupled ordinary differential equations which are then solved by employing the power series method the exact solution is valid for thick and thin plates and for arbitrary variation of material properties in the thickness direction results are presented for two constituent metal ceramic functionally graded rectangular plates that have a power law through the thickness variation of the volume fractions of the constituents the effective material properties at a point are estimated by either the mori tanaka or the self consistent schemes exact natural frequencies displacements and stresses are used to assess the accuracy of the classical plate theory the first order shear deformation theory and a third order shear deformation theory for functionally graded plates parametric studies are performed for varying ceramic volume fractions volume fraction profiles and length to thickness ratios results are also computed for a functionally graded plate that has a varying microstructure in the thickness direction using a combination of the mori tanaka and the self consistent methods forced vibrations of a plate with a sinusoidal spatial variation of the pressure applied on its top surface are scrutinized

hybrid uncertainty analysis of functionally graded plates via multiple imprecise random field modelling of uncertain material properties abstract this paper presents the mixed probabilistic non probabilistic uncertainty problem regarding the hybrid uncertainty propagation on physical model of functionally graded plates through dissimilarly uncertain characterisation of material properties in the presence of the multiple imprecise random field modelling the spectral stochastic finite element framework is extended to perform mixed uncertainty analysis of functionally graded material whereby the spatial variation of elastic modulus of the plate is uniquely characterised as the multiple imprecise random field modelling more than a purely homogeneous random field this characterisation has originated in heeding the construction of physical models and the significant influences of separately uncertain characteristics propagated on the physical model through different material ingredients are examined to make physical models more reliable and realistic mechanics and mathematics intrusive formulations are then established to explicitly produce the uncertain but bounded statistical characteristics of responses namely interval mean value interval standard deviation bounded surfaces of statistical moments and bounding distribution functions are vividly depicted for demonstration the feasibility and effectiveness of the presented work are illustrated via test cases of numerical examples

feature point correspondence in the presence of occlusion occlusion and poor feature point detection are two of the main difficulties in the use of multiple frames for establishing correspondence of feature points a formulation of the correspondence problem as an optimization problem is used to handle these difficulties modifications to an existing iterative optimization procedure for solving the formulation of the correspondence problem are discussed experimental results are presented to show the merits of the formulation

variable kinematic model for the analysis of functionally graded material plates this work addresses the static analysis of functionally graded material plates subjected to transverse mechanical loadings the unified formulation and principle of virtual displacements are employed to obtain both closed form and finite element solutions the use of the unified formulation permits a large variety of plate models with variable kinematic assumptions to be compared in the same framework these differ according to the order of the expansion in the thickness direction and the variable description the order of the expansion ranges from 1 to 4 thus covering first order as well as higher order theories the description of the unknowns can be equivalent single layer or layerwise the dependence of the material data on the thickness direction was introduced by employing thickness functions that are derived from the legendre polynomials that are used in the layerwise case the proposed approach is independent of the used transition function and as a result any continuous variations of the material properties in the thickness direction may be easily implemented the obtained solutions closed form and finite element are validated through comparison with three dimensional exact solutions and other available solutions these show the limitations of classical plate theories as well as the convenience of the use of the proposed variable kinematic models for the analysis of functionally graded material plates

asymptotics of wave motion in transversely isotropic plates abstract the present investigation is concerned with elastic wave motion in infinite transversely isotropic plate by asymptotic method the differential equations for the flexural and extensional motions are derived from the system of three dimensional dynamical equations of linear elasticity all coefficients of the differential operator are presented as explicit functions of the material parameter cs2 cl2 the ratio of the squared velocities of flexural shear and extensional longitudinal waves the velocity dispersion equations for the flexural and extensional wave motions are deduced analytically from the three dimensional analog of rayleigh lamb frequency equation for plates the approximations for long and short waves are also obtained the dispersion curves for phase velocity and group velocity spectrum are shown graphically for flexural and extensional wave motions of the plate the results for isotropic materials have been deduced as special cases

comutations underlying the measuremnt of visual motion abstract the organization of movement in a changing image provides a valuable source of information for analyzing the environment in terms of objects their motion in space and their three dimensional structure a description of this movement is not provided to our visual system directly however it must be inferred from the pattern of changing intensity that reaches the eye this paper examines the problem of motion measurement which we formulate as the computation of an instantaneous two dimensional velocity field initial motion measurements occur at the location of significant intensity changes as suggested by marr and ullman 1 these measurements provide only one component of velocity and must be integrated to compute the two dimensional velocity field a fundamental problem for this integration is that motion is not determined uniquely from the changing image an additional constraint of smoothness of the velocity field is formulated based on the physical assumption that surfaces are generally smooth allowing the computation of a unique solution a theoretical analysis of the conditions under which this computation yields the correct velocity field suggests that the solution is physically plausible empirical studies show the results to be consistent with human motion perception

structure from motion of rigid and jointed objects a method for recovering the three dimensional structure of moving rigid and jointed objects from several single camera views is presented the method is based on the fixed axis assumption all movement consists of translations and rotations about an axis that is fixed in direction for short periods of time this assumption makes it possible to recover the structure of any group of two or more rigidly connected points the structure of jointed objects is recovered by analyzing them as collections of rigid parts and then unifying the structures proposed for the parts the method presented here has been tested on several sets of data including movies used to demonstrate human perception of structure from motion

on the asymptotic spatial behaviour in the theory of mixtures of thermoelastic solids this paper is concerned with the study of asymptotic spatial behaviour of solutions in a mixture consisting of two thermoelastic solids a second order differential inequality for an adequate volumetric measure and the maximum principle for solutions of the one dimensional heat equation are used to establish a spatial decay estimate of solutions in an unbounded body occupied by the mixture for a fixed time the result in question proves that the mechanical and thermal effects are controlled by an exponential decay estimate in terms of the square of the distance from the support of the external given data the decay constant depends only on the thermal constitutive coefficients of the mixture

uniqueness and estimation of three dimensional motion parameters of rigid objects with curved surfaces two main results are established in this paper first we show that seven point correspondences are sufficient to uniquely determine from two perspective views the three dimensional motion parameters within a scale factor for the translations of a rigid object with curved surfaces the seven points should not be traversed by two planes with one plane containing the origin nor by a cone containing the origin second a set of essential parameters are introduced which uniquely determine the motion parameters up to a scale factor for the translations and can be estimated by solving a set of linear equations which are derived from the correspondences of eight image points the actual motion parameters can subsequently be determined by computing the singular value decomposition svd of a 3 3 matrix containing the essential parameters

generalized thermoelastic extensional and flexural wave motions in homogenous isotropic plate by using asymptotic method abstract in this paper the asymptotic method has been applied to investigate propagation of generalized thermoelastic waves in an infinite homogenous isotropic plate the governing equations for the extensional transversal and flexural motions are derived from the system of three dimensional dynamical equations of linear theories of generalized thermoelasticity the asymptotic operator plate model for extensional and flexural free vibrations in a homogenous thermoelastic plate leads to sixth and fifth degree polynomial secular equations respectively these secular equations govern frequency and phase velocity of various possible modes of wave propagation at all wavelengths the velocity dispersion equations for extensional and flexural wave motion are deduced from the three dimensional analog of rayleigh lamb frequency equation for thermoelastic plate the approximation for long and short waves along with expression for group velocity has also been obtained the rayleigh lamb frequency equations for the considered plate are expanded in power series in order to obtain polynomial frequency and velocity dispersion relations and its equivalence established with that of asymptotic method the numeric values for phase velocity group velocity and attenuation coefficients has also been obtained using mathcad software and are shown graphically for extensional and flexural waves in generalized theories of thermoelastic plate for solid helium material

perturbation theory for normal operators let e 3 x 7 a x be a c mapping with its values being un bounded normal operators with common domain of denition and compact resolvent here c stands for c1 c real analytic c m denjoy carleman of beurling or roumieu type c0 1 locally lipschitz or ck the param eter domain e is either r or rn or an innite dimensional convenient vector space we completely describe the c dependence on x of the eigenvalues and the eigenvectors of a x thereby we extend previously known results for self adjoint operators to normal operators partly improve them and show that they are best possible for normal matrices a x we obtain partly stronger results

flexural and transversal wave motion in homogeneous isotropic thermoelastic plates by using asymptotic method abstract the present investigation is concerned with the flexural and transversal wave motion in an infinite transversely isotropic thermoelastic plate by asymptotic method the governing equations for the flexural and transversal motions have been derived from the system of three dimensional dynamical equations of linear theory of coupled thermoelasticity the asymptotic operator plate model for free vibrations both flexural and transversal in a homogenous thermoelastic plate leads to fifth degree and cubic polynomial secular equations respectively that governs frequency and phase velocity of various possible modes of wave propagation at all wavelengths all the coefficients of differential operator have been expressed as explicit functions of the material parameters the velocity dispersion equations for the flexural and transversal wave motion have been deduced from the three dimensional analog of rayleigh lamb frequency equation for thermoelastic plate waves the approximations for long and short waves and expression for group velocity have also been derived the thermoelastic rayleigh lamb frequency equations for the considered plate are expanded in power series in order to obtain polynomial frequency and velocity dispersion relations whose equivalence is established with that of asymptotic method the dispersion curves for phase velocity group velocity and attenuation coefficient of various flexural and transversal wave modes are shown graphically for aluminum epoxy material elastic and thermoelastic plates

analysis of the dispersion spectrum of fluid loaded anisotropic plates flexural type branches and real valued loops abstract the subsonic spectrum of complex velocity versus real frequency in immersed anisotropic plates is considered for the various options of presupposed choice of modes in the loading fluid half spaces two principal implications of the latter prerequisite are investigated the first is related to the family of flexural type branches with origin at v 0 k 0 which evolve from the so called a 0 and a 1 free plate branches in a way that depends on the choice of fluid modes by inspecting the low frequency solutions of the dispersion equations corresponding to the different choices of fluid modes a complete set of the flexural type branches in an anisotropic fluid loaded plate is identified the result generalizes and also rectifies the interpretation commonly adopted for the isotropic case the second issue is concerned with the real valued loops on otherwise complex subsonic branches involving the fluid mode increasing away from the plate this phenomenon has been broadly discussed in numerical and experimental works on isotropic plates the topological origin and shape of the real loops for an arbitrary plate can be readily viewed by way of the graphical layout of the sextic plate formalism to this end three possibilities are considered namely the sound velocity in the fluid c f being i less than the rayleigh velocity ii greater than that but less than the bulk wave threshold in the plate and iii greater than the bulk wave threshold these lead to three basic configurations in case i a closed real loop exists provided than the fluid to solid density ratio is smaller than a certain critical value estimated here in a simple explicit form case ii is typically characterized by the presence of two open real valued arches with common high frequency limits case iii produces an infinite sequence of progressively narrowing real valued arches whose upper arms rise up to c f and then transform into descending curves of solutions associated with the decreasing fluid modes akin to the sezawa continuum a general overview of the locus of looping branches is supplied by analytical estimates and numerical examples

higher order piezoelectric plate theory derived from a three dimensional variational principle a three dimensional mixed variational principle is used toderive a kth order two dimensional lineartheory for an anisotropichomogeneouspiezoelectric pzt plate themechanicaldisplacements theelectricpotential theinplane components of the stress tensor and the in plane components of the electric displacement are expressed as a e niteseries of orderk inthethickness coordinate bytakinglegendrepolynomialsas thebasisfunctions however the transverse shear stress the transverse normal stress and the transverse electric displacement are expressed as a e nite series of order k 2 in the thickness coordinate the formulation accounts for the double forces without moments that may change the thickness of the plate results obtained by using the plate theory are given for the bending of a cantilever thick plate loaded on the top and the bottom surfaces by uniformly distributed 1 normal tractions and 2 tangential tractions results are also computed for the bending of a cantilever thick pzt beam loaded by 1 a uniformly distributed charge density on the top and the bottom surfaces and 2 equal and opposite normal tractions distributed uniformly only on a part of the beam the seventh order plate theory captures well the boundary layer effects near the clamped and the free edges and adjacent to the top and the bottom surfaces of a thick orthotropic cantilever beam with the span to the thickness ratio of two also through the thickness variation of the transverse shear and the transverse normal stresses agree well with those computed from the analytical solution of the three dimensional elasticity equations the governing partial differential equations are second order so that lagrange basis functions can be used to solve the problem by the e nite element method

vibration characteristics and transient response of shear deformable functionally graded plates in thermal environments free and forced vibration analyses for initially stressed functionally graded plates in thermal environment are presented material properties are assumed to be temperature dependent and graded in the thickness direction according to a simple power law distribution in terms of the volume fractions of the constituents theoretical formulations are based on reddy s higher order shear deformation plate theory and include the thermal effects due to uniform temperature variation the plate is assumed to be clamped on two opposite edges with the remaining two others either free simply supported or clamped one dimensional differential quadrature technique galerkin approach and the modal superposition method are used to determine the transient response of the plate subjected to lateral dynamic loads comprehensive numerical results for silicon nitride stainless steel rectangular plates are presented in dimensionless tabular and graphical forms the roles played by the constituent volume fraction index temperature rise shape and duration of dynamic loads initial membrane stresses as well as the character of boundary conditions are studied the results reveal that when thermal effects are considered functionally graded plates with material properties intermediate to those of isotropic ones do not necessarily have intermediate natural frequencies and dynamic responses

3 d motion estimation understanding and prediction from noisy image sequences this paper presents an approach to understanding general 3 d motion of a rigid body from image sequences based on dynamics a locally constant angular momentum lcam model is introduced the model is local in the sense that it is applied to a limited number of image frames at a time specifically the model constrains the motion over a local frame subsequence to be a superposition of precession and translation thus the instantaneous rotation axis of the object is allowed to change through the subsequence the trajectory of the rotation center is approximated by a vector polynomial the parameters of the model evolve in time so that they can adapt to long term changes in motion characteristics the nature and parameters of short term motion can be estimated continuously with the goal of understanding motion through the image sequence the estimation algorithm presented in this paper is linear i e the algorithm consists of solving simultaneous linear equations based on the assumption that the motion is smooth object positions and motion in the near future can be predicted and short missing subsequences can be recovered noise smoothing is achieved by overdetermination and a leastsquares criterion the framework is flexible in the sense that it allows both overdetermination in number of feature points and the number of image frames

three dimensional analysis for transient coupled thermoelastic response of a functionally graded rectangular plate abstract the generalized coupled thermoelasticity based on the lord shulman theory is considered to study the transient thermoelastic response of functionally graded rectangular plates the state equations of functionally graded rectangular plate subjected to time dependent thermal loads were established by using of state space approach in which three displacement components three stress components the temperature and the heat flux were chosen as state variables by giving simply supported boundary conditions and assuming that the material properties of the plate have an exponential law distribution along the thickness coordinate the equations were solved by the numerical laplace transformations and shooting methods for transient thermal responses of a three dimensional functionally graded rectangular plate due to a thermal shock on its top surface effects of the volume fraction distributions of material constituents on the thermal responses including the temperature change the displacement and the stresses distributions were investigated

two dimensional optimization of material composition of functionally graded materials using meshless analyses and a genetic algorithm abstract we propose a methodology for the two dimensional simulation and optimization of material distribution of functionally graded materials for thermomechanical processes the proposed approach focuses on metal ceramic functionally graded materials which offer great promise in applications where the operating conditions are severe the two dimensional quasi static heat conduction and thermoelasticity problems are analyzed using the element free galerkin method the spatial distribution of ceramic volume fraction is obtained by piecewise bicubic interpolation of volume fractions defined at a finite number of grid points the effective material properties at a point in the domain are estimated from the local volume fractions of the material constituents using the mori tanaka and self consistent homogenization schemes the volume fraction distribution is optimized using a real coded genetic algorithm the element free galerkin code is validated by comparing the results with an exact thermoelasticity solution for a simply supported plate subsequently we use the genetic algorithm and element free galerkin analyses to optimize the material composition for two model problems in the first problem we minimize the peak residual stress when the functionally graded component is cooled from a high fabrication temperature the goal of the second model problem is to minimize the mass of a graded component with constraints on the peak effective stress and maximum temperature experienced by the metal

the local structure of image discontinuities in one dimension the detailed structure of intensities in the local neighborhood of an edge can often indicate the nature of the physical event givinig rise to that edge we argue that the limit as we approach arbitrarily close to either side of an edge of such image parameters as type of texture texture gradient color appropriate directional derivatives of intensity etc is a key aspect of this structure however the general problem of capturing this local structure is surprisingly complex thus we restrict ourselves in this paper to a relatively simple domain one dimensional cuts through idealized images modeled by piecewise smooth c1 functions corrupted by gaussian noise within this domain we define local structure to be the limit of the uncorrupted intensity and of its derivatives as we approach arbitrarily close to either side of a discontinuity we develop a technique that captures this local structure while simultaneously locating the discontinuities and demonstrate that these tasks are in fact inseparable the technique is an extension using estimation theory of the classical definition of discontinuity it handles in a consistent fashion both jump discontinuities in the function and jump discontinuities in its first derivative so called step edges are a special case of the former and roof edges of the latter it also integrates again in a consistent fashion information derived from a number of different neighborhood sizes

an analysis of the elastic net approach to the traveling salesman problem this paper analyzes the elastic net approach durbin and willshaw 1987 to the traveling salesman problem of finding the shortest path through a set of cities the elastic net approach jointly minimizes the length of an arbitrary path in the plane and the distance between the path points and the cities the tradeoff between these two requirements is controlled by a scale parameter k a global minimum is found for large k and is then tracked to a small value in this paper we show that 1 in the small k limit the elastic path passes arbitrarily close to all the cities but that only one path point is attracted to each city 2 in the large k limit the net lies at the center of the set of cities and 3 at a critical value of k the energy function bifurcates we also show that this method can be interpreted in terms of extremizing a probability distribution controlled by k the minimum at a given k corresponds to the maximum a posteriori map bayesian estimate of the tour under a natural statistical interpretation the analysis presented in this paper gives us a better understanding of the behavior of the elastic net allows us to better choose the parameters for the optimization and suggests how to extend the underlying ideas to other domains

the convenient setting for non quasianalytic denjoy carleman differentiable mappings abstract for quasianalytic denjoy carleman differentiable function classes c q where the weight sequence q q k is log convex stable under derivations of moderate growth and also an l intersection see 1 6 we prove the following the category of c q mappings is cartesian closed in the sense that c q e c q f g c q e f g for convenient vector spaces applications to manifolds of mappings are given the group of c q diffeomorphisms is a regular c q lie group but not better

analytical solution for rectangular thick laminated plates subjected to arbitrary boundary conditions three dimensional deformations of a multilayered linear elastic anisotropic rectangular plate subjected to arbitrary boundary conditions at its edges are analyzed by the generalized eshelby stroh formalism the rectangular laminate consists of anisotropic and homogeneous laminae of arbitrary thicknesses perfect bonding is assumed between the adjoining laminae in the sense that both surface tractions and displacements are assumed to be continuous across their interfaces the analytical solution is in terms of infinite series and the effect of truncating the series on the accuracy of the solution is scrutinized the method is also applicable to rectangular laminated plates with edges of each lamina subjected to different boundary conditions results are presented for thick plates with different sets of edge boundary conditions e g two opposite edges simply supported and the other two subjected to eight different conditions or all four edges clamped

motion from point matches multiple of solutions in this paper we study the multiplicity of solutions of the motion problem given n point matches between two frames how many solutions are there to the motion problem we show that the maximum number of solutions is 10 when 5 point matches are available this settles a question that has been around in the computer vision community for a while we follow two tracks we show that the two approaches are compatible and yield the same result we then describe a computer implementation of the second approach that uses maple a language for symbolic computation the program allows us to compute exactly the solutions for any configuration of 5 points some experiments are described

point set registration coherent point drift point set registration is a key component in many computer vision tasks the goal of point set registration is to assign correspondences between two sets of points and to recover the transformation that maps one point set to the other multiple factors including an unknown nonrigid spatial transformation large dimensionality of point set noise and outliers make the point set registration a challenging problem we introduce a probabilistic method called the coherent point drift cpd algorithm for both rigid and nonrigid point set registration we consider the alignment of two point sets as a probability density estimation problem we fit the gaussian mixture model gmm centroids representing the first point set to the data the second point set by maximizing the likelihood we force the gmm centroids to move coherently as a group to preserve the topological structure of the point sets in the rigid case we impose the coherence constraint by reparameterization of gmm centroid locations with rigid parameters and derive a closed form solution of the maximization step of the em algorithm in arbitrary dimensions in the nonrigid case we impose the coherence constraint by regularizing the displacement field and using the variational calculus to derive the optimal transformation we also introduce a fast algorithm that reduces the method computation complexity to linear we test the cpd algorithm for both rigid and nonrigid transformations in the presence of noise outliers and missing points where cpd shows accurate results and outperforms current state of the art methods

correspondence problem in image sequence analysis abstract an algorithm to address the correspondence problem in image sequence analysis is proposed the underlying philosophy of this algorithm is reductionist and is based on the assertion that measurements pertaining to motion that are obtained from the whole image sequence must be very similar to the measurements that are obtained from corresponding portions of the image sequence the algorithm has been extensively tested on synthesized data as well as on real image sequences it appears that the assumption underlying the proposed algorithm is quite useful and applicable to a large class of images the proposed algorithm has a high degree of inherent parallelism and is thus suited for implementation on parallel machines

generalized plane strain thermoelastic deformation of laminated anisotropic thick plates the generalized plane strain quasi static thermoelastic deformations of laminated anisotropic thick plates are analyzed by using the eshelby stroh formalism the laminated plate consists of homogeneous laminae of arbitrary thicknesses the three dimensional equations of linear anisotropic thermoelasticity simplified to the case of generalized plane strain deformations are exactly satisfied at every point in the body the analytical solution is in terms of an infinite series the continuity conditions at the interfaces and boundary conditions at the bounding surfaces are used to determine the coeacients the formulation admits diaerent mechanical and thermal boundary conditions at the edges of each lamina and is applicable to thick and thin laminated plates results are computed for thick laminated plates with edges either rigidly clamped simply supported or traction free and compared with the predictions of the classical laminated plate theory and the first order shear deformation theory the boundary layer eaect near clamped and traction free edges is investigated 2001 elsevier science ltd all rights reserved

finding trajectories of feature points in a monocular image sequence identifying the same physical point in more than one image the correspondence problem is vital in motion analysis most research for establishing correspondence uses only two frames of a sequence to solve this problem by using a sequence of frames it is possible to exploit the fact that due to inertia the motion of an object cannot change instantaneously by using smoothness of motion it is possible to solve the correspondence problem for arbitrary motion of several nonrigid objects in a scene we formulate the correspondence problem as an optimization problem and propose an iterative algorithm to find trajectories of points in a monocular image sequence a modified form of this algorithm is useful in case of occlusion also we demonstrate the efficacy of this approach considering synthetic laboratory and real scenes

geometrically nonlinear analysis of functionally graded plates using a cell based smoothed three node plate element cs min3 based on the c0 hsdt abstract a cell based smoothed three node mindlin plate element cs min3 based on the first order shear deformation theory fsdt was recently proposed for static and dynamics analyses of mindlin plates in this paper the cs min3 is extended to geometrically nonlinear analysis of functionally graded plates fgps subjected to thermo mechanical loadings in the fgps the material properties are assumed to vary through the thickness by a simple power rule of the volume fractions of the constituents the nonlinear formulation is based on the c0 type high order shear deformation plate theory c0 hsdt and the von karman strains which deal with small strains and moderate rotations in the analysis process both thermal and mechanical loadings are considered and a two step procedure is performed including a step of analyzing the temperature field along the thickness of the plate and a step of analyzing the geometrically nonlinear behavior of the fgps subjected to both thermal and mechanical loadings the accuracy and reliability of the proposed method is verified by comparing its numerical solutions with those of available other numerical results

three dimensional analysis of transient thermal stresses in functionally graded plates an analytical solution is presented for three dimensional thermomechanical deformations of a simply supported functionally graded fg rectangular plate subjected to time dependent thermal loads on its top and or bottom surfaces material properties are taken to be analytical functions of the thickness coordinate the uncoupled quasi static linear thermoelasticity theory is adopted in which the change in temperature if any due to deformations is neglected a temperature function that identically satisfies thermal boundary conditions at the edges and the laplace transformation technique are used to reduce equations governing the transient heat conduction to an ordinary differential equation ode in the thickness coordinate which is solved by the power series method next the elasticity problem for the simply supported plate for each instantaneous temperature distribution is analyzed by using displacement functions that identically satisfy boundary conditions at the edges the resulting coupled odes with variable coefficients are also solved by the power series method the analytical solution is applicable to a plate of arbitrary thickness results are given for two constituent metal ceramic fg rectangular plates with a power law through the thickness variation of the volume fraction of the constituents the effective elastic moduli at a point are determined by either the mori tanaka or the self consistent scheme the transient temperature displacements and thermal stresses at several critical locations are presented for plates subjected to either time dependent temperature or heat flux prescribed on the top surface results are also given for various volume fractions of the two constituents volume fraction profiles and the two homogenization schemes 2003 elsevier ltd all rights reserved

three dimensional thermomechanical buckling of functionally graded materials three dimensional thermomechanical buckling analysis is discussed for functionally graded materials material properties are varied continuously in the thickness direction according to a simple power law distribution the three dimensional finite element model is adopted using an 18 node solid element and the assumed strain mixed formulation is used to prevent locking as well as to maintain kinematic stability for thin structures the thermal buckling behavior under time dependent temperature rise is compared with that under time independent temperature rise in time dependent temperature distribution temperature at each node is obtained by solving the thermomechanical equations and the crank nicolson method is used for a time discretization in the case of time independent temperature distribution thermal buckling is investigated under uniform linear and sinusoidal temperature rise numerical results are compared with those of previous works in addition the changes of critical buckling temperature due to temperature field volume fraction distributions and system geometric parameters are studied

exact solution for thermoelastic deformations of functionally graded thick rectangular plates an exact solution is obtained for three dimensional deformations of a simply supported functionally graded rectangular plate subjected to mechanical and thermal loads on its top and or bottom surfaces suitable temperature and displacement functions that identically satisfy boundary conditions at the edges are used to reduce the partial differential equations governing the thermomechanical deformations to a set of coupled ordinary differential equations in the thickness coordinate which are then solved by employing the power series method the exact solution is applicable to both thick and thin plates results are presented for two constituent metal ceramic functionally graded rectangular plates that have a power law through the thickness variation of the volume fractions of the constituents the effective material properties at a point are estimated by either the mori tanaka or the self consistentschemes exact displacementsand stressesatseveral locations for mechanical and thermal loads are used toassess theaccuracyof the classical plate theory thee rst ordershear deformation theory and athird order shear deformation theory for functionally graded plates results are alsocomputed for a functionally graded plate with material properties derived by the mori tanaka method the self consistent scheme and a combination of these two methods

control of nonlinear vibrations of functionally graded plates using 1 3 piezoelectric composite performance of the vertically obliquely reinforced 1 3 piezoelectric composite material as the constraining layer of the active constrained layer damping treatment for controlling geometrically nonlinear vibrations of the functionally graded plates subjected to a temperature field has been investigated unlike the existing analyses the finite element model uses the induced transverse normal stress in the active constraining layer for the active damping of nonlinear vibrations of the overall functionally graded plates the temperature field is assumed to be uniform over the substrate plate surfaces and varied through the thickness of the host functionally graded plates the temperature dependent material properties of the functionally graded substrate plates are assumed to be graded in the thickness direction of the plates according to a power law distribution and poisson s ratio is assumed to be a constant over the domain of the plate the constrained viscoelastic layer of the active constrained layer damping treatment is modeled using the golla hughes mctavish method the first order shear deformation theory and the green lagrange nonlinear strain displacement relations are used to model the open loop and closed loop nonlinear dynamics of the overall functionally graded substrate plates under a thermal environment the analysis suggests the potential use of the active constrained layer damping treatment with its constraining layer made of the vertically reinforced 1 3 piezoelectric composite material for active control of geometrically nonlinear vibrations of functionally graded plates in the absence or presence of the temperature gradient across the thickness ofthe plates the analysis also reveals that the active constrained layer damping patch is more effective for controlling the nonlinear vibrations of functionally graded plates when it is attached to the softest surface of the functionally graded plates than when it is bonded to the stiffest surface of the plates the effect of piezoelectric fiber orientation in the active constraining layer on the control authority of the active constrained layer damping treatment has also been investigated

on the problem of correspondence in range data and some inelastic uses for elastic nets in this work the authors propose a novel method to obtain correspondence between range data across image frames using neural like mechanisms the method is computationally efficient and tolerant of noise and missing points elastic nets which evolved out of research into mechanisms to establish ordered neural projections between structures of similar geometry are used to cast correspondence as an optimization problem this formulation is then used to obtain approximations to the motion parameters under the assumption of rigidity inelasticity these parameter scan be used to recover correspondence experimental results are presented to establish the veracity of the scheme and the method is compared to earlier attempts in this direction