Life Prediction for Turbine Engine Components

Fatigue ◽  
1983 ◽  
pp. 353-375 ◽  
Author(s):  
T. Nicholas ◽  
J. M. Larsen
Keyword(s):  
Life Prediction ◽  
Turbine Engine ◽  
Engine Components

Engine Component Life Prediction Methodology for Conceptual Design Investigations

1986 ◽  
Author(s):  
John D. Cyrus
Keyword(s):  
Life Prediction ◽  
Preliminary Design ◽  
Design Decisions ◽  
Turbine Engine ◽  
Detailed Consideration ◽  
Engine Design ◽  
Engine Component ◽  
Fundamental Understanding ◽  
Engine Components ◽  
The Impact

The increasing emphasis on engine durability requires that an analytical capability be acquired to assess engine component lives during the conceptual/preliminary design phases. A generalized methodology has been developed to provide a fundamental understanding of the impact of engine design decisions, material selections, and a detailed consideration of engine usage for critical gas turbine engine components.

Influence of Mission Variability on Fracture Risk of Gas Turbine Engine Components

2012 ◽  
Author(s):  
Michael P. Enright ◽  
Jonathan P. Moody ◽  
Ramesh Chandra ◽  
Alan C. Pentz
Keyword(s):  
Fracture Risk ◽  
Gas Turbine ◽  
Life Prediction ◽  
Damage Tolerance ◽  
Gas Turbine Engine ◽  
Fatigue Life Prediction ◽  
Turbine Engine ◽  
Risk Of Fracture ◽  
Failure Data ◽  
Engine Components

The need for application of probabilistic methods to fatigue life prediction of gas turbine engine components is being increasingly recognized by the U.S. Military. A physics-based probabilistic approach to risk assessment provides improved accuracy compared to a statistical assessment of failure data because it can be used to (1) predict future risk and (2) assess the influences of both deterministic and random variables that are not included in the failure data. Probabilistic risk and fatigue life prediction of gas turbine engine fracture critical components requires estimates of the applied stress and temperature values throughout the life of the component. These values are highly dependent upon the mission type and may vary from flight to flight within the same mission. Currently, standard missions are specified and used during the engine design process, but the associated stresses can differ significantly from stress values that are based on flight data recorder (FDR) information. For this reason, efforts are made to periodically update the standard missions and to assess the impact on component structural integrity and associated risk of fracture. In this paper, the influence of mission type and variability on fracture risk is illustrated for an actual gas turbine engine disk subjected to a number of different mission loadings. Disk stresses associated with each mission were obtained by scaling finite element model results based on RPM values obtained from engine flight recorder data. The variability in stress values throughout the life of the component was modeled using two different approaches to identify the upper and lower bound value influences on the risk of fracture. The remaining variables were based on default values provided in FAA Advisory Circular (AC) 33.14-1 “Damage Tolerance for High Energy Turbine Engine Rotors”. The risk of fracture was computed using a probabilistic damage tolerance computer code called DARWIN® (Design Assessment of Reliability With Inspection) and compared for each mission type to illustrate the maximum influence of mission type on fracture risk. The results can be used to gain insight regarding the influence of mission type and associated variability on the risk of fracture of realistic engine components.

Flexible manufacturing in repair of gas turbine engine components

1992 ◽  
Author(s):  
KIRK D ◽  
ANDREW VAVRECK ◽  
ERIC LITTLE ◽  
LESLIE JOHNSON ◽  
BRETT SAYLOR
Keyword(s):  
Gas Turbine ◽  
Flexible Manufacturing ◽  
Gas Turbine Engine ◽  
Turbine Engine ◽  
Engine Components

TIMETAL 829

Alloy Digest ◽  
2001 ◽  
Vol 50 (8) ◽  
Keyword(s):  
Fracture Toughness ◽  
Titanium Alloy ◽  
High Temperature ◽  
High Strength ◽  
Heat Treating ◽  
High Temperature Alloy ◽  
Turbine Engine ◽  
Major Application ◽  
Alpha Titanium ◽  
Engine Components

Abstract TIMETAL 829 is a Ti-5.5Al-3.5Sn-3Zr-1Nb-0.25Mo-0.3Si near-alpha titanium alloy that is weldable and has high strength and is a creep resistant high temperature alloy. The major application is as gas turbine engine components. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as fracture toughness, creep, and fatigue. It also includes information on forming and heat treating. Filing Code: TI-118. Producer or source: Timet.

Life assessment of a high temperature probe designed for performance evaluation and health monitoring of an aero gas turbine engine

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Benny George ◽  
Nagalingam Muthuveerappan
Keyword(s):  
Performance Evaluation ◽  
Gas Turbine ◽  
Health Monitoring ◽  
Gas Turbine Engine ◽  
Life Assessment ◽  
Exhaust Gas ◽  
Cycle Fatigue ◽  
Creep Life ◽  
Turbine Engine ◽  
Engine Components

AbstractTemperature probes of different designs were widely used in aero gas turbine engines for measurement of air and gas temperatures at various locations starting from inlet of fan to exhaust gas from the nozzle. Exhaust Gas Temperature (EGT) downstream of low pressure turbine is one of the key parameters in performance evaluation and digital engine control. The paper presents a holistic approach towards life assessment of a high temperature probe housing thermocouple sensors designed to measure EGT in an aero gas turbine engine. Stress and vibration analysis were carried out from mechanical integrity point of view and the same was evaluated in rig and on the engine. Application of 500 g load concept to clear the probe design was evolved. The design showed strength margin of more than 20% in terms of stress and vibratory loads. Coffin Manson criteria, Larsen Miller Parameter (LMP) were used to assess the Low Cycle Fatigue (LCF) and creep life while Goodman criteria was used to assess High Cycle Fatigue (HCF) margin. LCF and HCF are fatigue related damage from high frequency vibrations of engine components and from ground-air-ground engine cycles (zero-max-zero) respectively and both are of critical importance for ensuring structural integrity of engine components. The life estimation showed LCF life of more than 4000 mission reference cycles, infinite HCF life and well above 2000 h of creep life. This work had become an integral part of the health monitoring, performance evaluation as well as control system of the aero gas turbine engine.

Life assessment of a high temperature probe designed for performance evaluation and health monitoring of an aero gas turbine engine

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Benny George ◽  
Nagalingam Muthuveerappan
Keyword(s):  
Performance Evaluation ◽  
Gas Turbine ◽  
Health Monitoring ◽  
Gas Turbine Engine ◽  
Life Assessment ◽  
Exhaust Gas ◽  
Cycle Fatigue ◽  
Creep Life ◽  
Turbine Engine ◽  
Engine Components

Abstract Temperature probes of different designs were widely used in aero gas turbine engines for measurement of air and gas temperatures at various locations starting from inlet of fan to exhaust gas from the nozzle. Exhaust Gas Temperature (EGT) downstream of low pressure turbine is one of the key parameters in performance evaluation and digital engine control. The paper presents a holistic approach towards life assessment of a high temperature probe housing thermocouple sensors designed to measure EGT in an aero gas turbine engine. Stress and vibration analysis were carried out from mechanical integrity point of view and the same was evaluated in rig and on the engine. Application of 500 g load concept to clear the probe design was evolved. The design showed strength margin of more than 20% in terms of stress and vibratory loads. Coffin Manson criteria, Larsen Miller Parameter (LMP) were used to assess the Low Cycle Fatigue (LCF) and creep life while Goodman criteria was used to assess High Cycle Fatigue (HCF) margin. LCF and HCF are fatigue related damage from high frequency vibrations of engine components and from ground-air-ground engine cycles (zero-max-zero) respectively and both are of critical importance for ensuring structural integrity of engine components. The life estimation showed LCF life of more than 4000 mission reference cycles, infinite HCF life and well above 2000 h of creep life. This work had become an integral part of the health monitoring, performance evaluation as well as control system of the aero gas turbine engine.

Diagnosis of Turbine Engine Transient Performance With Model-Based Parameter Estimation Techniques

1994 ◽  
Author(s):  
Jeff W. Bird ◽  
Howard M. Schwartz
Keyword(s):  
Gas Turbine ◽  
Test Data ◽  
Physical Models ◽  
Turbine Engine ◽  
Robustness To Noise ◽  
Linear Effects ◽  
Diagnostic Capabilities ◽  
Engine Components ◽  
And Control ◽  
Parameter Estimation Techniques

This review surveys knowledge needed to develop an improved method of modelling the dynamics of gas turbine performance for fault diagnosis applications. Aerothermodynamic and control models of gas turbine processes are examined as complementary to models derived directly from test data. Extensive, often proprietary data are required for physical models of components, while system identification (SI) methods need data from specially-designed tests. Current methods are limited in: tuning models to test data, non-linear effects, component descriptions in SI models, robustness to noise, and inclusion of control systems and actuators. Conclusions are drawn that SI models could be formulated, with parameters which describe explicitly the functions of key engine components, to offer improved diagnostic capabilities.

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