Stasyuk B. Influence of contour curvature of plane cracks on stress intensity factor

The thesis is devoted to studying of three-dimensional state of stress in neighbourhood of plane cracks of the complicated form, which surfaces are under influence of self-balanced static loading. In work is elaborated the method of boundary integral equations. The special attention is paid to determination of stress intensity factors on the crack contour of changeable curvature. Problems of stress concentration in solids with cracks are reduced to solution of two-dimensional integral equations for determination of functions, which characterize the crack opening in the process of solid deformation. In the work is substantially applied the technique of reflection of areas, which are occupied by cracks on circular area. There were deduced a number of formulas for determination of stress intensity factor by means of the solution of corresponding boundary integral equations, which do not use the obvious expression of reconversion functions of circular area to crack area. The suggested technique has allowed to solve a class of new problems and on the basis of these solutions conclusions about influence of crack contour curvature on stress concentration in neighbourhood of cracks environment were made.