Kyrylova O. Stress state of cylindrical bodies with tunnel defects under harmonic vibrations

The thesis is devoted to the development of analytically-numerical method for the solving of problems of the stress state determination and resonance phenomena investigation in continuous and hollow cylindrical bodies of arbitrary cross-section with tunnel internal defects like cracks or thin rigid inclusions under time-harmonic loadings. The problems are reduced to 2D equations of motion in plane areas with defects, bounded by arbitrary smooth curves, under conditions of a plane and antiplane strain. The solution scheme is based on the use of discontinuous solutions of equations of motion of elastic medium with jumps of displacements or stresses on the surface of defects. By using the proposed method the calculations of SIF (stress intensity factor) in the vicinity of defects and numerical study of the resonance phenomena for continuous and hollow cylinders, the contours of which are ellipses or semi-ellipse connected by straight lines, with different methods of loading, are carried out.