A review of T-stress and its effects in fracture mechanics

A macroscopic constitutive law for porous solids with pressure-sensitive matrices and its implications to plastic flow localization

Effects of yield surface shape and round-off vertex on crack-tip fields for pressure-sensitive materials

The paper deals with the analysis of the T-effect in the problem of an interface macrocrack interacting with a microvoid in the process zone of the main crack tip. With the aid of the `pseudo-traction-edge-dislocation' method, the interaction problem with the T-effect under the remote field loading conditions can be reduced to singular Fredholm integral equations with Hilbert kernel. After solving the singular integral equations numerically, the T-effect on the main crack tip parameters is analyzed and the numerical results are given in figures.

T-effect for the interaction problem of an interface macrocrack with a near-tip microvoid

6 – FRACTURE MECHANICS and FATIGUE CRACK PROPAGATION

In this paper, we investigate the effects of the non-singular stress (T stress) on the mode I near-tip fields lbr elastic perfectly plastic pressure-sensitive materials under plane-stress and small-scale yielding conditions. The T stress is the normal stress parallel to the crack faces. The yield criterion for pressure-sensitive materials is described by a linear combination of the effective stress and the hydrostatic stress. Plastic dilatancy is introduced by the normality flow rule. The results of our finite element computations based on a two-parameter boundary layer formulation show that the total angular span of the plastic sectors of the near-tip fields increases with increasing T stress for materials with moderately la~rge pressure sensitivity. The T stress also has significant effects on the sizes and shapes of the plastic zones. The height of the plastic zone increases substantially as the T stress increases, especially for materials with large pressure sensitivity. When the plastic strains are considered to be finite as lbr transformation toughened ceramics, the results of our finite element computations indicate that the phase transformation zones for strong transformation ceramics with large pressure sensitivity can be approximated by those lbr elastic-plastic materials with no limit on plastic strains. When the T stress and the stress intensity factor K are prescribed in the two-parameter boundary layer formulation to simulate the crack-tip constraint condition tor a single-edge notch bend specimen of zirconia ceramics, our finite element computation shows a spear shape of the phase transformation zone which agrees well with the corresponding experimental observation.

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Influences of non-singular stresses on plane-stress near-tip fields for pressure-sensitive materials and applications to transformation toughened ceramics

Z. E. A. Ben-Aoun

Papers

Influences of non-singular stresses on plane-stress near-tip fields for pressure-sensitive materials and applications to transformation toughened ceramics