Dubrovskyi S. Determination of thermal cyclic durability of details of gas turbine engines made from heat-resistant materials with accounting operational loads

The work is dedicated to developing the methods of defining thermal cyclic durability of details made from heat-resistant materials. On the basis of the conducted analysis of the work conditions, damages and loads on main construction elements of the "hot part" of gas turbine engine it was proved, that the most important influences on the processes of creating cracks and destruction are making by that the cyclic thermal changes. They are accompanied by the action of integrated thermal and mechanical loads. Experimental equipment, methods and programs of running tests were elaborated and appraised. A mathematical model of calculating thermal cyclic durability of heat-resistant materials was created. The method of quantitative evaluation of the coefficient of relative durability was elaborated. The received values of the coefficient are recommended for the adjusted calculations of thermal cyclic durability of materials with the help of the hypothesis of linear summarizing of damages. A method of calculation of cyclic thermal fields in the samples was elaborated. Accuracy of the methods is proved with experimental data. Optimal values of the asymmetry coefficient were found on the base of the conducted research. Recommendations on an increasing durability of the details that are the subject to influence of thermal and cyclic load were elaborated.