A theoretically exact computational boundary is introduced, that is based on modal residual potentials for the spherical geometry. The boundary produces a set of first-order, uncoupled ordinary differential equations for nodal boundary responses, and a set of uncoupled time-stepping equations for modal boundary responses. The two sets are coupled through nodal-modal transformation based on the ...

The variational iteration method [1, 2], which is a modified general Lagrange multiplier method, has been shown to solve effectively, easily, and accurately a large class of nonlinear problems with approximations which converges (locally) to accurate solutions (if certain Lipschitz-continuity conditions are met). It was successfully applied to autonomous ordinary differential equations and nonl...

The shear stress distribution between a partially electroded thin piezoelectric film and a semi-infinite elastic substrate is analyzed. It is shown that the shear stress is governed by a pair of integro-differential equations. These equations are solved numerically using the concept of elements and the finite difference method. A few special cases are treated analytically. The behavior of the s...

Explicit solutions of differential equations complex fractional orders with respect to functions and continuous variable coefficients are established. The representations given in terms some convergent infinite series integro-differential operators, which can be widely efficiently used for analytic computational purposes. In the case constant coefficients, solution expressed multivariate Mittag...

In the research, special type of linear volterra integro-differential equations is considered. This paper compares the Homotopy perturbation method (HPM) with finite difference method for solving these equations. HPM is an analytical procedure for finding the solutions of problems which is based on the constructing a Homotopy with an imbedding parameter p that is considered as a small parameter...

this paper is concerned with investigation of vertical impedance function of a surface rigid circular foundation resting on a semi-infinite transversely isotropic alluvium. to this end, the equations of motion in cylindrical coordinate system, which because of axissymmetry are two coupled equations, are converted into one partial differential equation using a method of potential function. the g...

Lyapunov functions/functionals have found their footing in Volterra integro-differential equations. This is not the case for integral equations, and it therefore further explored this paper. In manuscript, we utilize functionals combined with Laplace transform to qualitatively analyze solutions of equation addition, extend our method nonlinear equations infinite delay, several kernels. We menti...