Evaluation of the Residual Service Life of Thin-Walled Structural Elements with Short Corrosion-Fatigue Cracks

2018 ◽  
Vol 53 (4) ◽  
pp. 514-521 ◽  
Author(s):  
O. E. Andreikiv ◽  
A. R. Lysyk ◽  
N. S. Shtayura ◽  
A. V. Babii
Keyword(s):  
Service Life ◽  
Corrosion Fatigue ◽  
Fatigue Cracks ◽  
Residual Service Life ◽  
Structural Elements ◽  
Thin Walled ◽  
Residual Service

Influence of the Geometry of Corrosion-Fatigue Cracks on the Residual Service Life of Objects Intended for Long-Term Operation

2019 ◽  
Vol 54 (5) ◽  
pp. 647-655
Author(s):  
E. І. Kryzhanivs’kyi ◽  
R. S. Hrabovs’kyi ◽  
О. Yu. Vytyaz’
Keyword(s):  
Service Life ◽  
Corrosion Fatigue ◽  
Fatigue Cracks ◽  
Residual Service Life ◽  
Term Operation ◽  
Residual Service

Influence of Corrosive Hydrogenating Media on the Residual Service Life of Structural Elements in the Maneuvering Mode of Operation

2018 ◽  
Vol 54 (1) ◽  
pp. 61-68 ◽  
Author(s):  
О. E. Andreikiv ◽  
V. R. Skal’s’kyi ◽  
І. Ya. Dolins’ka ◽  
А. R. Dzyubyk
Keyword(s):  
Service Life ◽  
Residual Service Life ◽  
Structural Elements ◽  
Mode Of Operation ◽  
Maneuvering Mode Of Operation ◽  
Residual Service

scholarly journals IMPROVEMENT OF METHODS OF TECHNICAL DIAGNOSIS OF PASSENGER RAILWAY CARS

2021 ◽  
Vol 1 (38) ◽  
pp. 80-87
Author(s):  
M. Radkevych ◽  
S. Sapronova ◽  
N. Braikovska ◽  
V. Tkachenko
Keyword(s):  
Service Life ◽  
Technical Diagnostics ◽  
Residual Service Life ◽  
Structural Elements ◽  
Passenger Car ◽  
Metal Structures ◽  
Long Operation ◽  
Theoretical Results ◽  
Residual Service ◽  
Standard Tests

Extension of the service life of a particular passenger railway car can be considered fully justified only if it is justified by the results of scientific and experimental research and approved by the relevant administrative documents of Ukrzaliznytsia the service life limit for wagons of this type. The existing method of technical diagnostics of passenger railway cars does not allow to fully assess the probability of extension of the service life of the car, because it does not take into account the peculiarities of damage to structural elements during operation. In the article the sequence of research of stresses in elements of a frame of a body of the passenger car of construction of KVN on the basis of standard tests is considered. The task of the study is to determine the sequence of calculation of stresses in the frame elements of the passenger car body of KСР (Kryukiv Carriage Plant) with a service life exceeding 41 years from the date of manufacture to assess strength and fatigue resistance by technical diagnostics and standard tests. It is concluded that the condition of the load-bearing metal structures of cars after long operation does not approach the limit. The residual resource was set at one of the minimum calculated values. If the results of calculations show that the resource is exhausted, the residual service life is determined by the results of bench tests for fatigue. The obtained practical and theoretical results make it possible to extend the service life of cars beyond that set by the manufacturer.

Functional and operational risk as a criterion for assessing the durability of an autonomous energy system

2019 ◽  
Vol 12 (1) ◽  
pp. 56-62 ◽  
Author(s):  
A. O. Nedosekin ◽  
A. V. Smirnov ◽  
D. P. Makarenko ◽  
Z. I. Abdoulaeva
Keyword(s):  
Service Life ◽  
Structural Reliability ◽  
Residual Life ◽  
Fuzzy Random Variable ◽  
Operational Risk ◽  
Energy System ◽  
Technical System ◽  
Residual Service Life ◽  
Technological Parameters ◽  
Residual Service

The article presents new models and methods for estimating the residual service life of an autonomous energy system, using the functional operational risk criterion (FOR). The purpose of the article is to demonstrate a new method of durability evaluation using the fuzzy logic and soft computing framework. Durability in the article is understood as a complex property directly adjacent to the complex property of system resilience, as understood in the Western practice of assessing and ensuring the reliability of technical systems. Due to the lack of reliable homogeneous statistics on system equipment failures and recoveries, triangular fuzzy estimates of failure and recovery intensities are used as fuzzy functions of time based on incomplete data and expert estimates. The FOR in the model is the possibility for the system availability ratio to be below the standard level. An example of the evaluation of the FOR and the residual service life of a redundant cold supply system of a special facility is considered. The transition from the paradigm of structural reliability to the paradigm of functional reliability based on the continuous degradation of the technological parameters of an autonomous energy system is considered. In this case, the FOR can no longer be evaluated by the criterion of a sudden failure, nor is it possible to build a Markov’s chain on discrete states of the technical system. Assuming this, it is appropriate to predict the defi ning functional parameters of a technical system as fuzzy functions of a general form and to estimate the residual service life of the technical system as a fuzzy random variable. Then the FOR is estimated as the possibility for the residual life of the technical system to be below its warranty period, as determined by the supplier of the equipment.

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