Трехмерная рентгеновская томография промышленных объектов при ограниченных размерах регистрирующего экрана

The article investigates the possibilities of using a 3D tomograph with a limited-sizes registering screen for detecting arbitrarily oriented crack-like defects in large industrial objects. Circular and spiral scanning schemes are considered, the principal possibility of detecting defects in the case of two-pass spiral scanning and a registering screen covering half of the view field of the test object cross-section is shown. The performance of the 3D reconstruction algorithm for the selected scanning method has been demonstrated.

Mode-III Stress Intensity Factors of an Arbitrarily Oriented Crack Crossing Interface in a Layered Structure

ABSTRACTThe problem of a layered structure containing an arbitrarily oriented crack crossing the interface in anti-plane elasticity is considered in this paper. The fundamental solution of displacements and stresses is obtained in a series form via the method of analytical continuation in conjunction with the alternating technique. A dislocation distribution along the prospective site of a crack is used to model a crack crossing the interface and the singular integral equations with logarithmic singular kernels for a line crack are then established. The crack is approximated by several line segments and the linear interpolation equation with undetermined coefficients was applied for the dislocation function along line segments. Once the undetermined dislocation coefficients are solved, the mode-III stress intensity factors KIII at two crack tips can be obtained for various crack inclinations with different material property combinations. All the numerical results are checked to achieve a good approximation that demonstrates the accuracy and the efficiency of the proposed method.