Damage Tolerance and Reliability of Turbine Engine Components

Damage Tolerance and Reliability of Turbine Engine Components
Author: Christos C. Chamis
Publisher:
Total Pages: 24
Release: 1999
Genre: Airplanes
ISBN:

This report describes a formal method to quantify structural damage tolerance and reliability in the presence of a multitude of uncertainties in turbine engine components. The method is based at the material behavior level where primitive variables with their respective scatter ranges are used to describe behavior. Computational simulation is then used to propagate the uncertainties to the structural scale where damage tolerance and reliability are usually specified. Several sample cases are described to illustrate the effectiveness, versatility, and maturity of the method. Typical results from this method demonstrate that it is mature and that it can be used to probabilistically evaluate turbine engine structural components. It may be inferred from the results that the method is suitable for probabilistically prediciting the remaining life in aging or deteriorating structures, for making strategic projections and plans, and for achieving better, cheaper, faster products that give competitive advantages in world markets.

Incorporating Residual Stresses in Life Prediction of Turbine Engine Disks

Incorporating Residual Stresses in Life Prediction of Turbine Engine Disks
Author: Reji John
Publisher:
Total Pages: 14
Release: 2003
Genre:
ISBN:

The U.S. Air Force has initiated a technology development initiative known as Engine Rotor Life Extension (ERLE), which has the goal of extending the useful lifetime of major, fracture-critical components in currently fielded gas turbine engines, without increasing the risk of component failure. Full achievement of this goal will require improvements in a broad range of technologies, including life prediction and fracture mechanics, nondestructive evaluation, engine usage and health monitoring, and component repair. This paper focuses on a key aspect of the life prediction process - the incorporation of residual stress effects. The benefits of compressive residual stresses in improving fatigue life, retardation of crack growth and resistance to foreign object damage have been demonstrated. Hence, the%se beneficial surface treatments are extensively employed in the turbine engine components. However, current damage-tolerance-based life management practices do not explicitly account for the residual stresses induced by surface enhancement procedures. Significant increase in predicted damage tolerance can be obtained if residual stresses are included in the life prediction methodology. This paper provides an assessment of the role of residual stresses in the durability of the component and identifies critical issues to be addressed during implementation in life prediction methods.

The Role of Spectrum Loading in Damage-Tolerance Life-Management of Fracture Critical Turbine Engine Components

The Role of Spectrum Loading in Damage-Tolerance Life-Management of Fracture Critical Turbine Engine Components
Author: James M. Larsen
Publisher:
Total Pages: 14
Release: 2003
Genre:
ISBN:

Recent developments in experimental and computational capabilities suggest an opportunity to develop improved models of crack growth for use in life management of materials and components in advanced gas turbine engines. Improvements in such models have potential benefits in the sustainment of aging engines, as well as the design of more durable future engines. Current approaches for life management of engine components tend to ignore potential increases in crack propagation lifetime that may occur as the result of load interaction phenomena under variable amplitude spectrum loading. In effort to quantify these potential benefits, a study of updated mission profiles was performed. A variety of engine usage spectra were surveyed to document their cycle content statistically, including characterization of the fundamental load sequence events and the expected severity of damage produced by these events, using data from the advanced nickel-base superalloy IN100.

Paper

Paper
Author:
Publisher:
Total Pages: 554
Release: 1993
Genre: Mechanical engineering
ISBN: