It's well known that the fracture processes in the solid bodies is determined mostly by the stress distribution near concentrators: micro-holes, crack tips etc. The plastic deformations plays an important role in such processes. Usually in fracture mechanics we solve the problem in the original ``continuous'' domain (without the holes and cracks) in order to obtain the local stress field (near concentrators) and then we deal with the elastico-plastic problem for the concentrator in unbounded domain.

We propose a technique of numerical solving the elastico-plastic boundary-value problems for several types of stress concentrators based on multigrid methods. We investigated some varieties of iteration process (such as V- and W-cycles, Richardson's extrapolation etc). The choice of the most efficient relaxation scheme is also discussed. Comparisons of the computational work of the multigrid methods and the several popular one-grid methods were performed. We also propose a method of the correspondent software development based on the object-oriented approach. We consider C++ class hierarchy that provides a flexible and convenient way of program packages design; C++ class library for the fracture mechanics problems was developed.