CONCEPTUAL ISSUES ON ENSURING THE RELIABILITY OF A FORCED DIESEL ENGINES PISTONS DURING A GIVEN RESOURCE

The design of modern power plants involves conducting calculation studies on the compliance of the structure with the established parameters of reliability and resource provision. However, there are cases when the structure, which according to the calculations is operational, fails in operation even before approaching the limit of its resource, and sometimes even at the beginning of operation. Such cases occur due to the fact that the materials used in the construction work at the limit of their strength, and sometimes crossing it, because in recent years there has been a constant increase in the capacity of power plants while maintaining the requirements for their resource. Thus, it becomes necessary to supplement the models to take into account a complex of factors affecting the physical and parametric reliability of the structure. The paper analyzes publications and sets a task for research, analyzes the main problems of loss of physical and parametric reliability of the piston, as one of the most thermally loaded structural elements, analyzes the thermally stressed state of characteristic critical zones of the piston, shows ways to ensure the reliability of pistons through adjusting the temperature state of structures. Based on the results of the analysis, the model for predicting the reliability of heat-stressed zones of parts of the cylinder-piston group was improved, the corresponding scheme of the integrated software complex was proposed, and the requirements for its application were formulated. The basis of the approach is the application of the criterion of physical reliability of structures and two criteria of their parametric reliability - from wear of friction pairs and not exceeding the creep limit of the material. This work makes it possible to obtain a design that is guaranteed to satisfy the requirements for physical and parametric reliability. The need for further work in the direction of expanding information about the properties of materials used in structures is also shown.