| Hybrid Contact Stress Analysis of a Turbine Engine Blade to Disk Attachment (Preprint) |
Jul 2011 |
|
| Authors:
Patrick J Golden; Sam Naboulsi; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
 | The present investigation examines an analysis methodology for fretting fatigue in a turbine engine fan disk. This is an important problem for the operators of turbine engines, since it is a significant driver of fatigue damage and failure risk of disks. Fretting fatigue in turbine engines occurs when the blade and disk are pressed together in contact and experience a small oscillating relative displacement due to variations in engine speed ... |
|
| Understanding Materials Uncertainty for Prognosis of Advanced Turbine Engine Materials (PREPRINT) |
Apr 2010 |
14 pages |
| Authors:
James M Larsen; M J Caton; A H Rosenberger; Reji John; J R Jira; Patrick J Golden; S K Jha; D J Buchanan; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| Materials damage prognosis offers the opportunity to revolutionize life management of advanced materials and structures through a combination of improved state awareness, physically based predictive models of damage and failure, and autonomic reasoning. Historically, lifetime and reliability limits for advanced fracture-critical turbine engine materials have been based on expected worst-case total life under fatigue. Recent findings in a variety of advanced propulsion alloys indicate that the life-limiting mechanisms are typically ... |
|
| Probabilistic Fretting Fatigue Life Prediction of Ti-6Al-4V (PREPRINT) |
Jan 2010 |
35 pages |
| Authors:
Patrick J Golden; Harry R Millwater; Xiaobin Yang; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| A probabilistic analysis of the fatigue life of specimens subject to fretting fatigue was developed. A mechanics based fretting life analysis was applied that employed the local stress gradient at the edge of contact. The random variables in the analysis included the initial crack size, coefficient of friction, crack growth rate law, and the contact pad profile. The variation in pad profiles was determined through measurement of seventy-seven machined pads. ... |
|
| Investigation of Variability in Fatigue Crack Nucleation and Propagation in Alpha+Beta Ti-6Al-4V |
Jan 2010 |
10 pages |
| Authors:
Patrick J Golden; Reji John; Porter; W J III; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| The understanding of fatigue variability in turbine engine materials is vital to permit a reduction of US Air Force sustainment costs through fatigue life extension and/or inspection interval extension. Additionally, the US Air Force is currently moving further towards the use of probabilistic damage tolerance design methods. These probabilistic models require not only a good understanding of the variability in specimen data, but also an understanding of the microstructural sources ... |
|
| Probabilistic Sensitivity Analysis of Fretting Fatigue (Preprint) |
Apr-2009 |
14 pages |
| Authors:
Patrick J Golden; Harry R Millwater; Xiaobin Yang; TEXAS UNIV AT SAN ANTONIO DEPT OF MECHANICAL ENGINEERING AND BIOMECHANICS
|
| A probabilistic analysis of the fatigue life of specimens subject to fretting fatigue was carried out. A mechanics based fretting life analysis was applied that accounted for the local stress gradient at the edge of contact. The random variables in the analysis included the initial crack size, coefficient of friction, crack growth rate law, and the contact pad profile. The variation in pad profiles was determined through statistical analysis of ... |
|
| Variability in Room Temperature Fatigue Life of Alpha+Beta Processed Ti-6Al-4V (Preprint) |
Oct-2008 |
17 pages |
| Authors:
Reji John; JOHN PORTER; Patrick J Golden; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| In this program, smooth bar fatigue tests were conducted by several laboratories on the same lot of Ti-6Al-4V forged plate material. Multiple stress ratios and stress levels were tested to generate a fully populated stress-life curve. The tests, however, did not typically consist of many repeats. The approach of this work is to conduct a statistically significant number of repeated fatigue tests at a few loading conditions. A similar approach ... |
|
| Influence of Residual Stresses on Fretting Fatigue Life Prediction in Ti-6Al-4V |
Jan-2008 |
28 pages |
| Authors:
Patrick J Golden; Dennis Buchanan; Sam Naboulsi; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| The objective of this work was to evaluate life prediction methodologies involving fretting fatigue of turbine engine materials with advanced surface treatments. Fretting fatigue tests were performed on Ti-6Al-4V dovetail specimens with and without advanced surface treatments. These tests were representative of the conditions found in a turbine engine blade to disk attachment. Laser shock processing and low plasticity burnishing have been shown to produce deep compressive residual stresses with ... |
|
| Influence of Residual Stresses on Fretting Fatigue Life Prediction in Ti-6Al-4V (POSTPRINT) |
Jan-2008 |
14 pages |
| Authors:
Patrick J Golden; Dennis Buchanan; Sam Naboulsi; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE
|
| The objective of this work was to evaluate life prediction methodologies involving fretting fatigue of turbine engine materials with advanced surface treatments. Fretting fatigue tests were performed on Ti-6Al-4V dovetail specimens with and without advanced surface treatments. These tests were representative of the conditions found in a turbine engine blade to disk attachment. Laser shock processing and low plasticity burnishing have been shown to produce deep compressive residual stresses with ... |
|
| Effects of Temperature and Frequency on the HCF Behavior of a Ni-based Superalloy |
01 Oct 2005 |
11 pages |
| Authors:
Ryan J Morrissey; Patrick J Golden; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH
|
| The objective of this research was to investigate the effects of temperature and frequency on the high cycle fatigue behavior of a single crystal superalloy using an ultrasonic fatigue system. Fatigue testing up to 109 cycles under fully reversed loading was performed at a temperature of 593 C (1100 F) to determine the ultra-high cycle fatigue behavior of PWA1484 at elevated temperature. Endurance limit results were compared to similar data ... |
|
Reports by Author
