Development relates to determination of the mechanical properties of pipes, namely for models designed for small-diameter pipe materials testing on crack resistance and can be used in the production and exploitation of pipes. The model to determine the crack resistance of small-diameter pipe, which is made in the form of a ring 1, cut out of the pipe, and fatigue crack Ring is designed as two symmetrical and opposing across-the-board cuts 2 on one of the ends of the model along the diameter of the ring. The use of the proposed model to determine the crack resistance of small-diameter pipe to improve prediction and study of survivability and security of small-diameter pipelines on the criteria of crack-resistance.
F.32 International patent
COBISS.SI-ID: 19076630The aim of this work is to estimate the hoop residual stresses in the tubes manufactured by hot rolling technique, since in most cases they are delivered only normalized, but not stress relieved too. Therefore, there are surly residual stresses present in tubes which are result of manufacturing technique, but also of uneven cooling after production process. Within this work, hoop stress as the most relevant for pipes and tubes is estimated by two methods: incremental hole drilling method and splitting method. Splitting method is a method for direct assessment of hoop stress in pipe or tube, since the incremental hole drilling method gives the results of principal stresses. So, in case of incremental hole drilling method, also the transformation of stresses is presented in order to obtain the hoop stress and make comparison to the splitting method. Although residual stresses are cause of collapse of many constructions, still in most cases of analysis and design of individual parts, structures and plants residual stresses are not taken into consideration. Due to the fact that residual stresses have significant effect on the fatigue behavior of materials as well as on the fracture toughness of material, it is recommended to take them into account while calculating the lifetime of component or structure
B.03 Paper at an international scientific conference
COBISS.SI-ID: 19062294