Alexander Galybin, Head of Damage Mechanics Division at WIT, delivered a lecture on Wednesday 13 July 2005 entitled 'Applications of BEM type approach to stress identification in engineering and geophysical problems'.
Diverse boundary value problems of plane elasticity have been discussed on the basis of uniform BEM type approach. These problems involve both classical and non-classical formulations. The latter, being usually ill-posed problems, require the application of a regularisation technique. It has been demonstrated that the use of SVD regularisation provides stability of solutions in contact and fracture mechanics problems that require the reconstruction of boundary stresses by monitoring displacements on stress-free boundaries.
Results of modelling of crack propagation under different types of loads and geometries have been outlined in order to describe fracture processes in heterogeneous and fragmented materials such as rocks, ceramics, concretes, etc. It has been shown that the BEM technique presents a convenient tool to provide accurate and fast analysis of fracture characteristics in diverse problems of civil engineering and mining.
Geophysical applications include the problem of stress identification in the earth’s crust from experimentally obtained data on stress orientations worldwide. It has been demonstrated that the stress tensor cannot be determined uniquely, although the number of arbitrary parameters entering into the solution is identified from the analysis of data. This analysis essentially narrows the class of possible stress fields that match observed stress orientations, which is advantageous as compare with the conventional inverse analysis widely applied in geophysics. Examples of stress fields have been shown for Western Europe, Australian continent, Antarctica plate and Sumatra region. This study is aimed at better understanding of geo-hazards such as earthquakes, land sliding, and tsunami initiation.