Evaluation of the service life of steam pipe knees of steel 12Kh1MF

ABSTRACTPhysical properties and structural parameters have been measured for ropes of nylon 6 as a function of the number of use operations. The fractional content of the α crystal form, sound velocity, birefringence, tensile strength and length all increase systematically and significantly with increasing the number of use operations. The fractional content of the γ crystal form and fiber diameter decrease with use. These trends indicate that the measurement of such properties and structural parameters, especially the length, provide a possible basis for establishing a reliable, rapid, and convenient nondestructive characterization method to predict the remaining service life of nylon 6 ropes.

Download Full-text

Evaluation of the residual service life of existing concrete structures: a valuable tool for maintenance planning

2nd International RILEM Workshop on Life Prediction and Aging Management of Concrete Structures ◽

10.1617/2912143780.020 ◽

2003 ◽

Author(s):

T. Teruzzi

Keyword(s):

Service Life ◽

Concrete Structures ◽

Residual Service Life ◽

Maintenance Planning ◽

Residual Service

Download Full-text

Development of Approaches to Solving the Problems of Ensuring Strength, Service Life and Safety of the Trunk Oil Transportation

Occupational Safety in Industry ◽

10.24000/0409-2961-2019-9-7-14 ◽

2019 ◽

pp. 7-14 ◽

Cited By ~ 1

Author(s):

N.A. Makhutov ◽

◽

Ya.M. Fridlyand ◽

A.A. Raspopov ◽

M.V. Lisanov ◽

...

Keyword(s):

Service Life ◽

Oil Transportation

Download Full-text

CARBONATION INDUCED CORROSION ANALYSIS OF REINFORCED CONCRETE STRUCTURES BASED ON FULL PROBABILISTIC APPROACH – AN INDONESIAN CASE STUDY

Malaysian Journal of Sustainable Environment ◽

10.24191/myse.v4i1.5612 ◽

2018 ◽

Vol 4 (1) ◽

pp. 165

Author(s):

Herry Prabowo ◽

Mochamad Hilmy

Keyword(s):

Service Life ◽

Probabilistic Approach ◽

Concrete Structures ◽

Weather Condition ◽

Analysis Data ◽

National Standard ◽

Concrete Carbonation ◽

Durability Design ◽

Starting Point ◽

Real Performance

The assessment of the service life of concrete structures using the durability design approach is widely accepted nowadays. It is really encouraged that a simulation model can resemble the real performance of concrete during the service life. This paper investigates the concrete carbonation through probabilistic analysis. Data regarding Indonesian construction practice were taken from Indonesian National Standard (SNI). Meanwhile, data related to Indonesian weather condition for instance humidity and temperature are taken from local Meteorological, Climatological, and Geophysical Agency from 2004 until 2016. Hopefully the results can be a starting point for durability of concrete research in Indonesia.

Download Full-text

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

Safety and Reliability of Power Industry ◽

10.24223/1999-5555-2019-12-1-56-62 ◽

2019 ◽

Vol 12 (1) ◽

pp. 56-62 ◽

Cited By ~ 1

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.

Download Full-text

On the effect of the periodicity of diagnostic measurements on improving the reliability of high-voltage transformers

Safety and Reliability of Power Industry ◽

10.24223/1999-5555-2019-12-1-18-21 ◽

2019 ◽

Vol 12 (1) ◽

pp. 18-21

Author(s):

V. A. Tikhonov

Keyword(s):

Service Life ◽

High Voltage ◽

Chromatographic Analysis ◽

Aluminum Industry ◽

Early Stage ◽

Diagnostic Methods ◽

Transformer Oil ◽

Operating Voltage ◽

Dissolved Gases ◽

The Aluminum Industry

The influence of the periodicity of diagnostic measurements on the operational state of high-voltage transformers is considered. Examples of defects of switching devices of converter transformers and methods for their detection are given. The rationale for the importance of recognition of defects at an early stage of their occurrence is given. The influence of the multiplicity of overvoltages on the service life of converter transformers in the aluminum industry is investigated. Based on the analysis of the service life of converter transformers of one of the powerful aluminum plants, where 83% of converter transformers have exhausted their standard service life, it is shown that in 40% of cases it would be possible to avoid their failures, with timely detection and elimination of emerging defects. Examples of defects of OLR (on-load regulators) of converter transformers and methods for their detection are given. The importance of recognition of defects at an early stage of their occurrence is substantiated. A method for chromatographic analysis of dissolved gases in transformer oil has been developed for the qualitative determination of defects and ways to eliminate them. Examples of diagnostics of converter transformers at operating voltage and working load are given, providing the best quality operational characteristics of converter transformers. The periodicity of diagnostic measurements and the reduction of defects and failures has been substantiated. The question of diagnosing the state of the converter transformer TDNP-40000/10 at an enterprise of the aluminum industry is investigated. Currently, diagnostic methods are being developed based on chromatographic analysis of dissolved gases in transformer oil. The presented method of evaluating the operating parameters of transformers allows for the safe operation of high-voltage transformers and enables to increase the reliability of the power supply scheme of aluminum industry plants.

Download Full-text