Kononova O. Method for rapid assessment of fatigue strength of restored ship propeller shafts

In the thesis, a method was developed to quickly assess the fatigue resistance of models of reconstructed ship propellers, within which the following tasks were solved. - a comparison was made of two approaches to assessing the fatigue strength of models of restored propeller shafts: according to their endurance limits and durability to failure; - based on the correlation dependences between the fatigue limit and the parameters of the sloping portion of the fatigue curve, expressed by a power equation, the dependence for determining the relative durability coefficient is refined. A correlation was also proposed for determining the endurance limit from the known value of this coefficient for the case of the absence of a common stress range in the high-cycle stress region. - analysis of the accuracy of the method of rapid assessment of the fatigue resistance of models of propeller shafts during their comparative tests. At the same time, both random factors affecting accuracy and systematic factors were considered; - the developed method was tested on samples and models of restored propeller shafts. Analysis of the results showed that the developed method allows for the operational comparative assessment of durability to failure at any of the stress levels, compared with analogs, the method allows us to clarify the shafts jf these logarithms ; durability up 8%. The results of the study constitute a methodological basis for conducting comparative tests of models of restored propeller shafts for testing the technologies for their repair. Key words: ship propeller shaft, repair, models, tests for fatigue resistance.