Papers by Author: Stojan Sedmak

Abstract: Fracture mechanics parameters can be applied for the analysis of failures of structures, and also for prevention of failures when defects in a structure are detected and defined. The approach is presented through stages: detection of defects, stress-strain analysis of loaded component, characterization of material properties required for structural integrity assessment and application of convenient procedure. In this way the decision about next use of defective component can be made (to continue the operation, increased care by inspection, exclusion the component from next service, with eventual repair, if possible). Special attention is paid to the most popular testing procedures for crack resistance parameters.

Abstract: Structural integrity and service reliability depend on the fracture resistance of a material. Cracks in the material are the locations of stress concentration, and elastic-plastic deformation can occur causing the development of mixed-mode type of fracture ahead the crack tip. Crack behavior in the elastic-plastic region is analyzed applying numerical and analytical simulation based on fracture mechanics parameters, characterizing the response of the material at the crack tip. Numerical and analytical results are compared with the corresponding experimental results obtained in previously performed fracture mechanics tests with standard single-edge notch bending – SEN(B) specimens. The comparison shows an acceptable level of agreement, enabling application of the proposed numerical model of crack growth in the mixed-mode fracture analysis for structural integrity assessment.