摘要:

The transverse crack propagation in the fibers of composites due to thermal stresses is studied using a micromechanical model and linear elastic fracture mechanics. The aim of this study is to investigate the effect of fiber-matrix mismatch and fiber elastic and thermal anisotropy on the transverse fiber cracking. To approach the problem, a three-domain cylindrical model is introduced to simulate the fiber cracking. The model problem is then solved using the technique of the dislocation and singular integral equation. The stress intensity factors of the fiber crack are calculated for various conditions (different fiber volume fractions, different fiber elastic or thermal expansion anisotropics, etc.). It is found that fiber elastic anisotropy has no perceptible effect on the transverse fiber cracking, whereas fiber thermal anisotropy affects the fiber transverse cracking in a somewhat intricate way.

ISSN:0149-5739    

DOI:10.1080/01495739408946253

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A new high-order laminated plate thermoelastic responses theory, which is based on a new mixed variational principle proposed by Reissner (1984) and accounts for transverse shear and transverse normal strains, is developed to study the thermoelastic behavior of a laminated composite plate. To this end, a zig-zag-shaped Cofunction and Legendre polynomials are introduced into the approximate displacement distributions across the plate thickness. The thickness variation of temperature is considered to be linear. The theory is examined by applying it to the thermal bending problem of cross-ply rectangular plates. The numerical results of central deflection and thickness variation of in-plane and transverse thermal stresses are obtained for symmetric and antisymmetric cross-ply plates.

ISSN:0149-5739    

DOI:10.1080/01495739408946254

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

An experimental study of plate buckling induced by spatial temperature gradients is described. A rectangular Hastelloy-X plate is subjected to local line heating by a focused quartz heat lamp. Two parallel plate edges are maintained at constant temperature by coolant flow. Point supports provide well-defined thermal-structural boundary conditions. Test results including temperature and displacements from transient elastic and inelastic tests demonstrate that substantial plate bending occurs due to initial plate warpage and thermally induced membrane compressive stresses.

ISSN:0149-5739    

DOI:10.1080/01495739408946255

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The two-dimensional problem of an infinitely long circular cylinder whose lateral surface is traction-free and subjected to an asymmetrical heating is considered within the context of the theory of generalized thermoelasticity with one relaxation time. The solution is obtained by a direct approach, in which an additive function derived from the governing equations is introduced Laplace transform and series expansion techniques are used to derive the solution in the Laplace transform domain. Numerical inversion of the Laplace transforms is carried out to obtain the temperature and stress distributions inside the cylinder. Numerical results are represented graphically and discussed Comparison is made with the solution of the corresponding coupled problem.

ISSN:0149-5739    

DOI:10.1080/01495739408946256

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A simple C0isoparametric finite element formulation based on a higher-order displacement model for the analysis of symmetric and unsymmetric, composite, and sandwich laminates subjected to a thermal gradient across the thickness is presented. The displacement model accounts for the nonlinear distribution of in-plane displacement components through the plate thickness, and the theory requires no shear correction coefficients. The nine-noded quadratic Lagrangian two-dimensional element is used with five and nine degrees of freedom per node. The accuracy of the formulation is verified by analyzing sample problems available in literature. Numerical results are presented in nondimensional form for symmetric, antisymmetric, and cross-ply laminates, both thick and thin.

ISSN:0149-5739    

DOI:10.1080/01495739408946257

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

A formulation of the boundary integral equation method for theromoelasticity with two relaxation times is given. Fundamental solutions of the corresponding differential equations are obtained. A reciprocity theorem is derived. An outline of the implementation of the boundary element method is discussed for the solution of the above boundary equations. Special emphasis is given to the representation of the primary fields, namely, temperature and displacement.

ISSN:0149-5739    

DOI:10.1080/01495739408946258

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Boundary value problems for a circular-arc crack embedded in an infinite medium due to a point heat source are formulated and solved in closed form. Based on the Hilbert problem formulation and a special technique of contour integration, exact solutions of a semicircular crack are obtained in an explicit form. It is found that the thermal stresses or temperature giadient near the tips of a curved crack always possess the characteristic inverse square-root singularity in terms of the radial distance away from the crack tip under the application of a heat source. The simultaneous existence of mode-I and mode-II stress intensity factors are shown in this article to be dependent on the strength of a heat source, heat conductivity, as well as thermal and elastic isotropy. The nonnegative mode-I stress intensity factor is found to be present in this article for the application of the heat sink, which validates the fully open crack assumption.

ISSN:0149-5739    

DOI:10.1080/01495739408946259

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

The problem associated with an interface crack between anisotropic dissimilar media subjected to a remote heat flux as welt as traction on the crack surface is studied in this article. Based on the complex variable representations of the plane elastic problem developed by Lekhnitskii and a special technique of analytical continuation, the full field solutions of the displacements and thermal stresses are obtained in closed form. It is indicated that the nature of singularities in the stress field at the crack tips is unaltered by the presence of an applied heat flux if the heat conductivity coefficients obey the Onsager reciprocal relations. The explicit expressions for the strain energy release rate and crack opening displacements are also provided. The former is treated as the fracture parameter to characterize the occurrence of interface cracking. Numerical examples for graphite / epoxy composite bonded to metal and ceramic materials bonded to metal substrates are examined and detailed results are given.

ISSN:0149-5739    

DOI:10.1080/01495739408946260

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

In this section, publications on thermal stresses that have appeared elsewhere are listed. In order to make the list as complete as possible, authors are requested to submit two copies of their publications to the Editor-in-Chief. Publications in languages other than English should be accompanied by the English translation of their titles.

ISSN:0149-5739    

DOI:10.1080/01495739408946261

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor