The article considers the method of forecasting the initial stage of fatigue failure of the propeller shaft of the vessel, consisting of the following stages: 1) «preparatory» - determination of the initial calculation data, 2) «pre-calculation» - numerical modeling, 3) «calculation» - prediction of the initial stage of fatigue failure. 4) «final» - analysis of the calculation results and interpretation of the received data. The preparatory stage consists of: determining the geometric parameters and mechanical properties of the propeller shaft; studying the features of operation, manufacturing technology and technical condition; study of the loading mode and the values of the current predicted loads; Analysis of the need to introduce additional loads, based on the operating conditions and calculation of the value of the current unpredictable loads; checking for the presence of initial stress concentrators. The pre-calculation stage consists of: building a spatial geometric model; setting the material characteristics and creating a solid-state model; building a finite-element model by discretizing the internal space with a grid of calculated elements of finite volume; setting boundary conditions; analysis of the obtained calculation results by determining the «dangerous» points and the values of stresses and deformations at these points. The calculation stage consists of: determining the value of the critical crack length; determining the third stage of fatigue failure; determining the total durability based on the regression equation of the fatigue failure of the material; directly calculating the duration of the initial stage of fatigue failure. The final stage is to analyze the calculation results and interpret the data obtained.
fatigue failure, the prediction of durability, ships propeller shaft, propeller shaft
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