Cheredarchuk N. Method of comparative indirect estimation of endurance limit of restored crankshafts of internal combustion engines

In the dissertation work the method of indirect comparative accelerated estimation of fatigue resistance of the restored crankshafts of internal combustion engines is developed, which allows to improve the process of repair of these products. For its development, theoretical substantiation and verification of accuracy, a number of the following tasks were previously solved. The possibility of using destructive stress for indirect comparative assessment of fatigue strength of restored crankshafts of internal combustion engines is scientifically substantiated. With the help of correlations between the parameters of the fatigue curve and the endurance limit, the possibility of estimated estimation of destructive stresses for restored crankshafts of internal combustion engines is proved. The influence of bends and breaks of the experimental fatigue curve of the restored crankshafts of the internal combustion engine on the value of the calculated values of the destructive stresses at linearly increasing load is estimated. The use of a two-link fatigue curve to clarify the values of destructive stresses in the calculated assessment of the fatigue strength of the restored crankshafts of the internal combustion engine with increasing load is substantiated. The analysis of accuracy of the developed method is carried out taking into account influence of speed of increase of loading, and also casual and systematic components of the general error. The accuracy of the developed accelerated method on laboratory samples and elements of the restored crankshafts of internal combustion engines according to the data published in literature sources is checked.