摘要:

A three-dimensional asymptotic scheme that combines the transfer matrix method and the asymptotic expansion technique is used to analyze thermo-electro-mechanical deformations of a piezothermoelastic laminate with surface tractions, electric potentials, and temperatures specified on its top and bottom surfaces. The scheme results in a hierarchy of two-dimensional equations with the same homogeneous operator for each order. For an elastic problem, the homogeneous operator reduces to that for classical thin-plate equations. Results computed for a simply supported rectangular plate with edges grounded are found to be in excellent agreement with the exact solution of the problem.

ISSN:0149-5739    

DOI:10.1080/014957300280470

出版商:Informa UK Ltd    

年代:2000

数据来源: Taylor

摘要:

Two refined higher order theories, one that neglects and the other that takes into account the effect of transverse normal deformation, are used to develop two discrete finite element models for the thermal buckling analysis of composite laminates and sandwiches. The two models, one with nine degrees of freedom per node and the other with eleven degrees of freedom, are based on a nine-node Lagrangian isoparametric element. The geometric stiffness matrices are developed by taking into consideration the effects of the higher order terms on the initial in-plane and transverse shear stresses. The accuracy of the present formulations is first evaluated by analyzing sample problems for which analytical three-dimensional solutions exist in the literature. Numerical results are presented for the first time for sandwich plates, demonstrating the importance and accuracy of the higher order theory in comparison to first-order theory. Some new results are also given for sandwich plates with angle-ply composite face sheets, showing the effects of various boundary conditions and of variations in geometric and lamina tion parameters on critical temperature.

ISSN:0149-5739    

DOI:10.1080/014957300280489

出版商:Informa UK Ltd    

年代:2000

数据来源: Taylor

摘要:

A probabilistic finite-element approach for modeling the temperature and displacement fields in structures is proposed. The theoretical formulation of the problem is described. It presents probabilistic distributions for temperature and displacement taking into account the random thermal properties of a material. An example of the thermal analysis in random conditions is demonstrated.

ISSN:0149-5739    

DOI:10.1080/014957300280498

出版商:Informa UK Ltd    

年代:2000

数据来源: Taylor

摘要:

The problem considered in this article is the response of a graded composite material plate containing some noncollinear cracks subjected to dynamic thermal loading. It is assumed that all the material properties depend only on the coordinates y (along the thickness direction) . In the analysis, graded regions are treated as a series of perfectly bonded composite layers, each layer being assigned slightly different material properties. Utilizing the Laplace transform and Fourier transform techniques, the general solution for each layer is derived. The complete solution of the entire medium is then obtained by introducing the mechanical boundary and layer interface conditions. The main features of the proposed method are: (1) the material may be orthotropic, (2) multiple crack problem, (3) the material properties may vary arbitrarily along the thickness direction, and (4) with the inertial terms taken into account, the present algorithm can be applied to a fracture problem under dynamic mechanical loading. Numerical examples are provided for a FGM and a substrate FGM coating structure under a nonuniform heating condition. Transient and steady-state thermal stress intensity factors are calculated and their variation due to a change of the material gradient and the location of the crack are studied.

ISSN:0149-5739    

DOI:10.1080/014957300280506

出版商:Informa UK Ltd    

年代:2000

数据来源: Taylor

摘要:

The induced temperature, displacement, and stress fields in an infinite nonhomoge neous viscoelastic aeolotropic solid having a spherical cavity are obtained. The medium considered is heated by a distributed heat source in such a way that the flux changes exponentially in the radial direction. The type of nonhomogeneity is such that the elastic constants and the coefficient of linear thermal expansion are proportional to the nth power of the radial distance. The viscoelastic nature of the material is characterized by a model where the elastic constants are replaced by appropriate differential operators. The problem is solved analytically employing the integral transform technique. Numeri cal values of the field quantities at different points of the medium at different instants of time are computed for an exemplary case.

ISSN:0149-5739    

DOI:10.1080/014957300280515

出版商:Informa UK Ltd    

年代:2000

数据来源: Taylor

ISSN:0149-5739    

DOI:10.1080/014957300280524

出版商:Informa UK Ltd    

年代:2000

数据来源: Taylor