Search

The paper analyzes new publications on the brittle fracture mechanics of prestressed materials. It is found out that new scientific results published in the International Journal of Solids and Structures in 2002 are a particular case of the results obtained at the Institute of Mechanics 20 years ago [ABSTRACT FROM AUTHOR]

The paper presents experimental results on the deformation, local buckling, and fracture of D16AT plates with two parallel edge cracks under tension. The distribution of strains and deflections over typical cross-sections and buckling modes are determined. The influence of the crack length and the distance between the cracks on the local buckling stresses and breaking stresses is studied. The effect of local buckling on the strength of the plate is evaluated [ABSTRACT FROM AUTHOR]

The paper is concerned with the determination of edge effect zone in a laminated composite with laminas subject to longitudinal compression. The dependence of the maximum decay length on the ratio between the period of external loading and the structure parameter is studied. The load period depends on the number of unloaded laminas. The decay of the edge effect is analyzed by numerically solving a boundary-value problem of elasticity for piecewise-homogeneous materials and using a quantitative decay criterion for the near-edge normal stresses [ABSTRACT FROM AUTHOR]

The paper reports on the results from analysis of some nonclassical fracture problems that allow for stresses along cracks. The results have been obtained by the author and his collaborators at the Institute of Mechanics (Kiev) since 1980 [ABSTRACT FROM AUTHOR]

We will solve a fracture-mechanics problem for an elastic material with cracks subject to a polyharmonic load created by longitudinal waves with different wavelengths propagating through the material. The frictionless contact between the edges of a finite-length plane crack under the action of two normal harmonic tension/compression waves with different frequencies is studied. The forces of contact interaction and displacement discontinuity are analyzed. The effect of the wave frequency on the stress intensity factor is examined for different normalized wave numbers. [ABSTRACT FROM AUTHOR]

The three-dimensional stress state of a transversely isotropic plate with a nearly circular cylindrical cavity is examined. The cavity surface is subject to normal and tangential stresses and the plate is subject at infinity to tensile and shear forces. The problem is solved by expanding unknown functions into Fourier-Legendre series in the thickness coordinate and using the boundary-shape perturbation method. The equations and recurrence formulas needed to solve the problem in an arbitrary approximation are presented [ABSTRACT FROM AUTHOR]

New representations of the stress tensor in the linear theory of elasticity and thermoelasticity are proposed. These representations satisfy the equilibrium equations and the strain compatibility equation. The stress tensor is expressed in terms of a harmonic tensor or a harmonic vector. The second boundary-value problem for an elastic half-space and an elastic layer is solved as an example [ABSTRACT FROM AUTHOR]

The contact interaction of a pneumatic tire with a roadbed is studied. The discrepancy between the Gim-Nikravesh analytic model and experimental data is established to be due to the one-dimensionality of the model and the assumption that the pressure of the wheel on the roadbed is symmetric [ABSTRACT FROM AUTHOR]

A two-level fracture model of composites with cracks under compression is proposed. Fiber-reinforced laminated panels with a hole are considered. The panels are compressed along the fibers so that two cracks propagate from the hole boundary at a right angle to the loading direction. The fracture mechanism is analyzed at two levels. The first level is the compression-induced stress concentration at the tip of a finite-thickness crack filled with a fractured material. At this level, the theory of elasticity of linear orthotropic body is used. The second level is compression fracture at the crack tip. The analysis performed at this level involves the three-dimensional linearized theory of stability of solids, considering microcracks in the interface between the fractured and intact materials, and the exact solution describing the compression-induced instability of the cracked interface. The second level is where results obtained by the author are used. Thus, the approach proposed employs the theory of elasticity of linear orthotropic body and the three-dimensional linearized theory of stability of solids to analyze a specific mechanism of fracture [ABSTRACT FROM AUTHOR]

The structural theory of short-term damage is generalized to the case where the undamaged components of anN-component laminar composite deform nonlinearly. The basis for this generalization is the stochastic elasticity equations for anN-component laminar composite with porous components whose skeleton deforms nonlinearly. Microvolumes of the composite components meet the Huber-Mises failure criterion. Damaged microvolume balance equations are derived for the physically nonlinear materials of the composite components. Together with the equations relating macrostresses and macrostrains of the laminar composite with porous nonlinear components, they constitute a closed-form system. This system describes the coupled processes of physically nonlinear deformation and microdamage. For a two-component laminar composite, algorithms for calculating the microdamage-macrostrain relationship and plotting deformation curves are proposed. Uniaxial tension curves are plotted for the case where microdamages occur in the linearly hardening component and do not in the linearly elastic component [ABSTRACT FROM AUTHOR]

A review is given of studies devoted to problems and methods of evaluating the effective resistance to macrocrack growth in materials with microdamages and in materials reinforced with small rigid inclusions under mechanical and thermal loads. Also an analysis is made of the three-dimensional interaction of penny-shaped microcracks and macrocracks in isotropic and transversely isotropic materials. Related publications based on methods and models other than those used by the authors are reviewed. [ABSTRACT FROM AUTHOR]