| Description |
A new eigenfunction expansion method is developed to obtain three-dimensional asymptotic stress fields in the vicinity of (a) an interior point and (b) the surface corner point located at the front of a (i) homogeneous and (ii) bimaterial wedge, subjected to three combinations of wedge-side boundary conditions - clamped-clamped, clamped-free and free-free. In comparison with the existing method, the present method is much easier to implement, and is also computationally more efficient in the sense that it does not need to resort to iterative schemes to solve the three partial differential equations, which limits the former's applicability to more complex geometric shapes, such as a wedge. Expressions for singular stress fields in the neighborhood of an interior point and the surface corner point located at the front of a semiinfinite crack - a special case of a homogeneous wedge - are also presented. Likewise, expressions for singular stress fields in the neighborhood of these points located at the front of a semiinfinite crack along the interface- a special case of a bimaterial wedge - are also presented. Additionally, heretofore unavailable numerical results, especially for threedimensional stress fields in the vicinity of the surface corner point at the front of a (i) homogeneous and (ii) bimaterial wedge subjected to the aforementioned wedge-side boundary conditions, and their comparisons with their two-dimensional (i.e., plane stress) counterparts are also presented. Relative dominance of the computed eigenvalues (i.e., order of singularity) for different types of loading, such as extension/bending and antiplane shear is also studied in this investigation. The relationship between the strain energy release rate and the stress intensity factor is investigated from a three-dimensional standpoint. Furthermore, numerical results pertaining to development of plastic yield zone at the front of a semiinfinite crack are also obtained. Finally, derivation of the general stress intensity factor (for e=£±7c) and the corresponding expressions of singular stresses for homogeneous wedges also form a part of this dissertation research. |
