Antiplane strain of an elliptical cylinder with a crack

The antiplane strain of an anisotropic elliptical cylinder with a crack is examined. An infinite system of linear algebraic equations is obtained from the boundary conditions on the cylinder surface to determine the constants in the complex potential of the problem. Detailed numerical investigations are performed of the influence of the geometric and elastic characteristics of the cylinder on the magnitude of the stress intensity coefficients near the outer edge.Translated from Teoreticheskaya i Prikladnaya Mekhanika, No. 18, pp. 28–34, 1987.     

Antiplane strain of a multiconnected anisotropic body with longitudinal cavities and plane cracks

Applying the theory of generalized complex potentials and the method of least squares, we solve the problem of the stressed state of a multiconnected anisotropic body under an antiplane strain. The problem is reduced to a system of linear algebraic equations in the unknown constants that occur in the required functions. By numerical studies we exhibit the influence of the elastic and geometric characteristics on the stress distribution and the variation of the stress intensity factors in a cylinder with one or two cracks and in an infinite body with circular cavities and cracks. One figure. Six tables. Translated fromTeoreticheskaya i Prikladnaya Mekhanika, No. 25. 1995, pp. 56–62.     

Antiplane deformation of an isotropic massif with a curvilinear cavity

We solve the problem of antiplane deformation for an infinite isotropic massif with a curvilinear cavity in which a harmonic shear wave is propagating. The solution of the problem, which is based on the application of the theory of functions of a complex variable, is reduced to finding unknown constants from a system of linear algebraic equations. Numerical results are given for a circular cavity. Translated fromTeoreticheskaya i Prikladnaya Mekhanika, No. 23, 1992, pp. 115–119.     

Delayed fracture of an orthotropic body subjected to two-dimensional deformation

A modified δ_C is used to solve for the subcritical growth of macroscopic cracks of a normal cleavage in ageing fiber composite acted on by constant tensile stresses applied at infinity under two-dimensional deformation conditions. A continued fraction expansion is used to interpret the nonrational function of the integral Maslov-Arutyunyan ageing operators. The convergence of the resulting expansion is studied numerically, along with changes in the durability and safe loading conditions for an ageing composite as a function of the filling. Institute of Mechanics, National Academy of Sciences of Ukraine, Kiev. Translated from Teoreticheskaya i Prikladnaya Mekhanika, No. 30, pp. 84–91, 1999.     

Geometrically nonlinear dilation of an orthotropic plane with an elliptical hole

In a geometrically nonlinear formulation we obtain expressions for the stresses and displacements on the edge of an elliptical hole in an orthotropic plane dilated by a strain at infinity in the direction of the principal axes of anisotropy. We exhibit the dependence of the concentration of stresses on the magnitude of the load acting on the plane. We prove that the stresses are finite at the ends of the crack and we compute their values. We confirm the need to take account of the geometric nonlinearity of the problem for low-modulus orthotropic materials.Translated fromMatematicheskie Metody i Fiziko-Mekhanicheskie Polya, Issue 28, 1988, pp. 90–96.     

The three-dimensional expansion-contraction problem for an orthotropic plate with elliptic cavities

On the basis of functions of generalized complex variables that are exact solutions of the three-dimensional equations of the theory of elasticity of an orthotropic body, we construct the solution for studying the stress state of a plate with elliptic cavities. We use the projection-grid method on the transverse coordinate. As basis functions we have chosen functions of compact support. We have carried out numerical studies for a plate with one elliptic cavity. Three tables. Bibliography: 8 titles. Translated fromTeoreticheskaya i Prikladnaya Mekhanika, No. 26, 1996, pp. 20–27.     

Scattering of plane harmonic waves on a cylindrical cavity with an elliptical cross section in an orthotropic medium

The diffraction of a plane longitudinal harmonic wave on a cavity with a smooth curvilinear cross section in a rectilinearly orthotropic medium is solved by using small perturbations in the elastic moduli and introducing generalized wave potentials. Results are presented from a numerical analysis of the dynamic stresses in the near diffraction field and at the boundary of an elliptical cavity including variations in the relative incident wavelength, eccentricity of the cavity, and degree of anisotropy of the medium. Donetsk State University. Translated from Teoreticheskaya i Prikladnaya Mekhanika, No. 29, pp. 102–110, 1999.     

Steady planar vibrations of an isotropic body with cavities

We solve the planar-deformation problem for a multiconnected isotropic body deformed by a pulsing load. For a circular cylinder with a circular central cavity we give the results of numerical studies of the stress distribution and the frequencies of the natural axisymmetric vibrations. Translated fromTeoreticheskaya i Prikladnaya Mekhanika, No. 24, 1993, pp. 69–74.     

Antiplane shear deformation of piezoelectric bodies in contact with a conductive support

We consider a mathematical model which describes the frictional contact between a piezoelectric body and an electrically conductive support. We model the material’s behavior with an electro-elastic constitutive law; the frictional contact is described with a boundary condition involving Clarke’s generalized gradient and the electrical condition on the contact surface is modelled using the subdifferential of a proper, convex and lower semicontinuous function. We derive a variational formulation of the model and then, using a fixed point theorem for set valued mappings, we prove the existence of at least one weak solution. Finally, the uniqueness of the solution is discussed; the investigation is based on arguments in the theory of variational-hemivariational inequalities.     

Terminal motion of a thin elliptical plate over a horizontal plane with orthotropic friction

The problem on the terminal motion of a thin elliptic plate over a horizontal plane taking into account orthotropic friction forces has been considered. Differential equations of the movement of the plate have been derived. The system of equations has been numerically solved under various initial conditions. It has been shown that sliding and spinning cease simultaneously. It has been found that the limiting behavior of the plate is governed not only by the ratio of the moment of inertia to the coefficient of friction, but also by the orientation of the plate. A comparison of the behaviors of the elliptic and circular plates has been carried out. The results of the calculations can be used to describe the phenomena that occur in a rail–wheel contact in more detail.     

Axially symmetrical deformation of an orthotropic layered cylindrical shell

An orthotropic layered cylindrical sheet subject to axially symmetrical loading is considered. A solution free from the hypothesis of the straight normal is presented; the material of the shell is regarded as incompressible in the radial direction. An attempt is made to allow for the real character of the rigid fixing at the edge of the shell. The stressed state in the neighborhood of the edge is analyzed.S. Ordzhonikidze Moscow Aviation Institute. Translated from Mekhanika Polimerov, No. 5, pp. 816–823, September–October, 1972.     

A study of the strength of an elastoplastic orthotropic shell of arbitrary curvature with a surface crack

Using an analog of the δ _c -model, we have obtained a solution of the problem of the stress-strain state of an elastoplastic orthotropic shell, having an arbitrary curvature, with a surface crack. Here, additional constraints on the elastic parameters of the material are not imposed. Furthermore, we have studied the dependence of the length of the plastic zone and surface-crack opening on the level of load, the shell and crack geometrical parameters, and the mechanical properties of the material.     

Stress-strain relationships with nonlinear deformation of orthotropic glass-reinforced plastics

A theory of nonlinear elasticity of anisotropic bodies of the flow theory type is used to investigate nonlinear strains in orthotropic glass-reinforced plastics. Its applicability is experimentally confirmed (for two types of GRP) and the strain-hardening function employed in the theory is plotted. Simplified relationships are derived for direct loading and the relations obtained are compared with the strain theory of nonlinearelastic anisotropic bodies.Mekhanika Polimerov, Vol. 1, No. 4, pp. 28–34, 1965     

The three-dimensional problem of the axisymmetric deformation of an orthotropic spherical layer

A 3D problem of the deformation of an elastic orthotropic spherical layer that is subjected to normal pressure applied to its outer and inner surfaces is analyzed. Asymptotic first-order approximation solutions are obtained for a slightly orthotropic layer for which the elastic moduli in the meridional and circumferential directions have similar values. The solutions that are obtained are used for analyzing the scleral shell under intraocular pressure; however, they can also be used for solving the inverse problem of analyzing the stress–strain state of a human eye during intravitreal injections. The influence that the meridional and circumferential elastic moduli have on the magnitudes of changes in the relative layer thickness and in the length of the anteroposterior eye axis due to elevated intraocular pressure is studied.     

Stressed state of an anisotropic body with elliptical holes, elastic inclusions, and cracks

A method is proposed for studying the two-dimensional stressed state of a multiply connected anisotropic body with cavities and elastic and rigid inclusions, as well as planar cracks and rigid laminar inclusions. Generalized complex potentials, conformal mapping, and the method of least squares are used. The problem is reduced to solving a system of linear algebraic equations. Formulas are given for finding the stress intensity factors in the case of cracks and laminar inclusions. For an anisotropic plate with a single elliptical hole or a crack and an elastic (rigid) inclusion, some numerical results are presented from a study of the effect of the rigidity of the inclusion and the closeness of the contours to one another on the distribution of stresses and the stress intensity factor. Translated from Teoreticheskaya i Prikladnaya Mekhanika, No. 30, pp. 175–187, 1999.