Abstract
The purpose is to determine the impact of operating conditions on the reliability of vehicles, to identify the main causes of failure of truck units and assemblies and to find ways to improve their reliability. The main methods are a systematic approach to analysis of complex technological systems, the fault tree analysis to identify the most common causes of failure of trucks in the climatic conditions of Central Asia. It has been revealed that one of the frequent causes of failure of units and assemblies is fatigue failure, the finite element modelling of which allowed the study to obtain a diagram of limit deviations for various cycle asymmetries and as a result, the ability to predict the process of fatigue failure under the influence of external factors. The study results are aimed at the possibility of predicting the failure of components and assemblies of trucks conditioned by fatigue failure.