in this paper, a general solution for torsion of hollow cylinders made of functionally graded materials (fgm) was investigated. the problem was formulated in terms of prandtl’s stress and, in general, the shear stress and angle of twist were derived. variations in the material properties such as young’s modulus and poisson’s ratio might be arbitrary functions of the radial coordinate. various m...

We establish a lower bound for the gradient of the solution to∞-Laplace equation in a strongly star-shaped annulus with capacity type boundary conditions. The proof involves properties of the radial derivative of the solution, so that starshapedness of level sets easily follows.

This article presents an exact solution for an axisymmetric functionally graded piezoelectric (FGP) rotating disk with constant thickness subjected to an electric field and thermal gradient. All mechanical, thermal and piezoelectric properties except for Poisson’s ratio are taken in the form of power functions in radial direction. After solving the heat transfer equation, first a symmetric dist...

Time-dependent creep analysis is crucial for the performance and reliability of piezoactuators used for high-precision positioning and load-bearing applications. In this study history of stresses, deformations and electric potential of hollow rotating cylinders made of functionally graded piezoelectric material (FGPM), e.g., PZT_7A have been investigated using Mendelson’s method of successive e...

Based on the radial basis function (RBF), nonsingular general solution, and dual reciprocity method (DRM), this paper presents an inherently meshless, integration-free, boundaryonly RBF collocation technique for numerical solution of various partial differential equation systems. The basic ideas behind this methodology are very mathematically simple. In this study, the RBFs are employed to appr...