Theoretical and practical issues of processing digital information in the problems related to durability assessment in conditions of loading are considered. Due to the specifics of the problem, in which the precise dedermination of the extreme values and their sequence is of primary importance, a number of generally accepted recommendations appeared invalid. For example, the Kotelnikov theorem, which was originally proposed in relation to the problems of estimating the frequency composition of the process, can lead to significant errors. It is shown that the requirements to the analysis of random loading processes with a goal of further assessment of the durability, due to their specificity, contradict with the specified requirements, namely, when choosing a frequency according to this rule, an error can be made, and not to the margin of the strength assessment. We considered the issue regarding digital filtering of hardware overshoots. Alternative approaches to the selection of extrema of the random process are analyzed: 1) direct hardware selection of extrema and 2) discretization by the method of level crossings. The latter approach has an optimal algorithm for isolating extremes and makes it possible to isolate extremes of a random process with lower costs and greater accuracy. The natural transition to integer arithmetic provides further optimization of the algorithm. The model and real examples demonstrate gains in terms of speed and memory, which ultimately promote an increase in the reliability of the information required for assessing the durability. The savings in memory and performance will allow processing of long-term implementations and result in a more accurate estimating of the remaining life and durability at the stage of production.

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For a reasonable and reliable assessment of durability at the design or operation stage of the tracked vehicles, it is required information about the loading process, which is usually obtained by registering the load by various methods, such as strain measurement. For a reliable assessment of loading and, consequently, durability, the question arises about the representative length of the loading process recording. The paper proposes a method for determining the necessary and sufficient realization length using various methods of processing of the recorded random loading realization. The efficiency of the proposed method is demonstrated by the example of the evaluation of the random loading processes in torsion shafts of the suspension systems of a high-speed tracked vehicle. The justification of the necessary and sufficient length of the record of the random loading process is given.

The analysis is carried out under an operating load level for a crack located on the cylindrical part of the torsion shaft, the plane of which is at an angle to the torsion shaft axis and coincides with the position of the main areas of the stress state. The calculation of fracture toughness is based on Irwin fracture criterion. The calculations of the maximum stress intensity factor along the crack front are performed using the finite element method in the ANSYS software package. The results of the analysis of fracture toughness are presented in the form of dependences of the critical depth of the crack on the ratio of the fracture half-length to its depth. The data obtained can be used to determine the residual life of torsion shafts of the tracked vehicles based on the chassis under consideration.