scholarly journals A Method to Estimate Service Boundary Conditions for Hot-Gas-Path Components of a Gas Turbine by Using a Design of Experiments. 1st Report. Residual Life Assessment Using an Inverse Analysis.

2002 ◽  
Vol 68 (671) ◽  
pp. 1143-1148 ◽  
Author(s):  
Yasushi HAYASAKA ◽  
Shigeo SAKURAI ◽  
Isao TAKEHARA
Keyword(s):  
Design Of Experiments ◽  
Boundary Conditions ◽  
Gas Turbine ◽  
Inverse Analysis ◽  
Residual Life ◽  
Life Assessment ◽  
Hot Gas ◽  
Residual Life Assessment

Life Management System for Hot-Gas-Path Components of Gas Turbines

1999 ◽  
Author(s):  
Yasushi Hayasaka ◽  
Nobuhiro Isobe ◽  
Shigeo Sakurai ◽  
Kazuhiko Kumata
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Management System ◽  
Residual Life ◽  
Combined Cycle ◽  
Operating Conditions ◽  
Life Assessment ◽  
Hot Gas ◽  
Life Management ◽  
Residual Life Assessment

Recently the number of gas-turbine-powered combined-cycle plants has been increasing because of their efficiency and environmental compatibility. Gas turbine operating conditions are severe, especially for hot-gas-path components. To improve the reliability of such components and to extend their life, we have developed a life management system based on a residual-life-assessment method. The system makes possible integrated residual-life-assessment based on numerical analyses, material destructive-tests, nondestructive inspections, statistical analyses of field machine data, and the use of a database. To develop the system, the primary damage mechanism for each component is clarified and material degradation is evaluated. For nozzles, the system describes a method of predicting the maximum surface crack growth. The validity of the methods is verified by assessment of the inspection data. This paper also describes optimization of operating cost and RAM (reliability, availability and maintainability).

Residual Life Assessment of a Critical Component of a Gas Turbine: Achievements and Challenges

2014 ◽  
Author(s):  
Wieslaw Beres ◽  
Zhong Zhang ◽  
David Dudzinski ◽  
W. R. Chen ◽  
X. J. Wu
Keyword(s):  
Crack Propagation ◽  
Gas Turbine ◽  
Mixed Mode ◽  
Residual Life ◽  
Crack Nucleation ◽  
Three Dimensional ◽  
Life Assessment ◽  
Mode Interaction ◽  
Turbine Engine ◽  
Residual Life Assessment

The residual life assessment of a turbine spacer from a gas turbine engine is presented. The spacer has been identified as one of the safety critical components of the engine, therefore the useful life of this component significantly affects economic operation of the fleet. Numerical analyses of fatigue crack propagation at one critical location of the spacer were performed using both three dimensional (3D) finite element based method and the weight function method. These results combined with the material data allowed for basic assessment of the damage tolerance of this component. Experimental validation of the spacer life was performed in a spin rig facility. During this validation, two sets of spacers were tested and the number of cycles to appearance of a detectable crack was recorded. Moreover, a fractographic study was conducted on the fracture surfaces of two spin rig tested spacers using scanning electronic microscopy techniques. It was found that crack nucleation occurred at multiple sites and crack propagation occurred by a mixed mode of striation formation and faceted fracture. Therefore it was concluded that the mixed mode interaction should be considered in predicting the fatigue life of the spacer. Finally, the paper describes the challenges and pitfalls encountered during preparation and execution of the analyses and tests, including availability of engine and operational data and also uncertainties in interpretation of the results.

Gas turbine hot section components: The challenge of ‘residual life’ assessment

2000 ◽  
Vol 214 (3) ◽  
pp. 193-201 ◽  
Author(s):  
M I Wood
Keyword(s):  
Gas Turbine ◽  
Residual Life ◽  
Life Assessment ◽  
Residual Life Assessment ◽  
Assessment Procedures

Gas turbine hot section parts are high-value components which have finite lives. Their durability has an important role in controlling maintenance intervals and the associated costs. This paper reviews the sources of degradation in some components, the technology available to quantify the damage, and publicly available assessment procedures which can be used for component life assessment.

Residual service life estimation of bridges

2021 ◽  
Author(s):  
Mayank Bajaj ◽  
Biswajit Bhattacharjee
Keyword(s):  
Residual Life ◽  
Concrete Bridges ◽  
Life Assessment ◽  
Residual Service Life ◽  
Chloride Ingress ◽  
Service Life Estimation ◽  
Residual Life Assessment ◽  
Existing Bridges ◽  
Residual Service

<p>While concrete structures perform well in many situations, lack of durability has emerged as a significant issue for asset owners. A review of past bridge failures was done to identify the most probable causes of bridge failures. This study has tended to focus on current models used for estimating the time to deterioration of concrete bridges instigated by Chloride ingress and Fatigue. Subsequently, mathematical modelling of the best-suited deterioration model is done to arrive at the residual life of two existing bridges. This work has highlighted high variability in the parameters used to describe the durability related properties of in-situ aged concrete. A realistic residual life assessment can be achieved by correct evaluation of these parameters by periodic testing of bridge samples</p>

Criterial relationships for residual life assessment of materials

2006 ◽  
Vol 38 (4) ◽  
pp. 348-353 ◽  
Author(s):  
A. A. Lebedev ◽  
V. M. Mikhalevich
Keyword(s):  
Residual Life ◽  
Life Assessment ◽  
Residual Life Assessment

Residual Life Assessment for Boiler Pressure Components Based on Measurements of Creep Strains

1988 ◽  
Vol 110 (3) ◽  
pp. 308-313 ◽  
Author(s):  
F. Mlynarski ◽  
J. Taler
Keyword(s):  
Residual Life ◽  
Life Assessment ◽  
Strain Measurements ◽  
Years Of Service ◽  
Residual Life Assessment ◽  
Outside Diameter ◽  
Creep Strains

This paper discusses different methods for calculating the residual life for boiler pressure components operating under creep conditions, based on tube outside diameter strain measurements. These measurements were made for over 20 yr. The methods have been applied to the residual life calculation for pipelines of 20 or more years of service. Then the results have been compared.

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