Fundamentals of Evaluation and Diagnostics of Welded Structures

Cambridge International Science Publishing

FUNDAMENTALS OF CALCULATIONS AND DIAGNOSTICS OF WELDED STRUCTURES

A Ya NEDOSEKA

The author deals with the main problems in ensuring the safe service of structures and installations encountered in calculating the strength of these structures, in tests and during service. The methods of calculating and measuring temperature fields, stresses and strains are outlined and fundamentals of fracture mechanics discussed. Special attention is given to the theory, methods and means of diagnostics and evaluation of the state of the material of structures and to its residual life. The main questions of the theory of prediction and decision-making in evaluating the state of structures are discussed. The book will be of interest to students and engineers concerned with the inspection and diagnostics of structures. Temperature field in welding (calculation methods, welding heat sources, theory of integral transformations, thermal conductivity equation, examples of calculating temperature fields in welding, continuous and moving heat sources) Welding stresses and strains (thermophysical and mechanical properties of materials, welding stresses and strains under concentrated heating, residual stresses in welding butt joints and patches, welding stresses and strains under a multiaxial stress state, main dependences used in measuring thermophysical and mechanical quantities, measurement of residual stresses) Load-carrying capacity of welded structures (special features of calculating the strength of welded structures in the presence of various defects, external conditions and loading methods, fracture mechanics, prefailure state and fracture of welded joints and materials, quantum fracture mechanics, bending a circular plate, method of fictitious forces in solving problems of stability of plates with welded joints, welding strains). Diagnostics and prediction of the residual life of welded structures (main problems of technical diagnostics, prediction methods, factorial analysis, image recognition methods, diagnostics and residual life of structures, service lie of structural materials, other problems of acoustic emission) Appendix (mathematical processing of inspection results, evaluation of errors in numerical calculations, empirical equations, mechanical and technological tests of materials, stress state in vessels operating under pressure, stress concentration)