Zengtao Chen

Thermal fracture of cracked cylinders associated with nonclassical heat conduction: The effect of material property

ABSTRACT The thermoelastic problem of a transversely isotropic hollow cylinder containing a circumferential crack is investigated in the present article based on the non-Fourier heat conduction theory. The temperature and stress fields are obtained by solving the coupled partial differential equations in the Laplace domain, and corresponding thermal axial stress with minus sign is then applied to the crack surface to form a mode I crack problem. Three different kinds of crack are considered, and the singular integral equation method is adopted to solve the fracture problem. Finally, with the definition of stress intensity factor, the effect of material properties, coupling parameter, and crack geometry on the hyperbolic thermal fracture responses of a transversely isotropic hollow cylinder excited by a thermal loading is visualized.

Analysis of arbitrarily shaped planar cracks in three-dimensional isotropic hygrothermoelastic media

ABSTRACT In the present article, a planar crack of arbitrary shape embedded in three-dimensional isotropic hygrothermoelastic media is investigated. Based on the general solutions and Hankel transform technique, the fundamental solutions for unit-point and extended displacement discontinuities (EDD; including the displacement discontinuities, moisture concentration discontinuity, and the temperature discontinuity) are derived. The EDD boundary integral equations for an arbitrarily shaped, planar crack in the hygrothermoelastic medium are established in terms of the EDD. Utilizing the boundary integral equation method, the singularities of near-crack front fields are analyzed, and the stress, moisture flux, and heat flux intensity factors are all derived in terms of the EDD. As a special case, the analytical solution for a penny-shaped crack under uniform combined loadings is presented. The EDD boundary element method is proposed for numerical simulation. The numerical result for a penny-shaped crack subjected to uniform mechanical–moisture–thermal loading is compared with the analytical solution to verify the correctness of the proposed method. Two coplanar elliptical cracks subjected to combined loadings are simulated as an application, and the influences of applied loadings and the ellipticity ratio are discussed.

Three-dimensional steady-state general solution for isotropic hygrothermoelastic media

ABSTRACT The potential theory method was utilized to derive the steady-state general solution for three-dimensional (3D) hygrothermoelastic media. Two displacement functions are introduced to simplify the governing equations, with which the elastic, moisture, and temperature fields are thus simplified. Using the differential operator theory and superposition principle, all the physical quantities can be expressed in terms of two functions, one of which satisfies a harmonic equation and the other satisfies an eight-order partial differential equation. With the aid of generalized Almansi’s theorem, all the physical quantities like displacements, moisture, and temperature are expressed in terms of five quasi-harmonic functions for various cases of material characteristic roots. The obtained general solutions are in simple form and thus they may bring more convenience to certain boundary problems. As an example, the fundamental solutions for a point moisture source combined with heat source in the interior of infinite hygrothermoelastic body are presented by virtue of the obtained general solution. A planar crack of arbitrary shape in an infinite medium subjected to mechanical, moisture, and temperature loads is investigated to illustrate the application of the solution in boundary value problems. Specifically, for a penny-shaped crack under uniform combined loads, the complete, exact solutions are presented.

Two-dimensional thermal shock problem of generalized thermoelastic multilayered structures considering interfacial conditions

ABSTRACT A two-dimensional model of the generalized thermoelasticity with one relaxation time is established. The resulting nondimensional coupled equations together with the Laplace and Fourier transform techniques are applied to a specific problem of multilayered structures considering thermal resistance subjected to thermal shock and traction-free surface. The solutions in the transformed domain are obtained by a direct approach. Numerical inversion techniques are used to obtain the inverse double transform. Numerical results are represented graphically to estimate the effects of the thermal resistance and thermal conductivities on the temperature, displacement, and stress distributions.