Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Widespread Fatigue Damage In Military Aircraft PDF full book. Access full book title Widespread Fatigue Damage In Military Aircraft.
| Author | : North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Structures and Materials Panel. Meeting |
| Publisher | : |
| Total Pages | : 228 |
| Release | : 1995 |
| Genre | : Airframes |
| ISBN | : |
| Author | : |
| Publisher | : |
| Total Pages | : 214 |
| Release | : 1995 |
| Genre | : |
| ISBN | : |
A structure potentially susceptible to Widespread Fatigue Damage (WFD) is defined by the Industry Committee on Widespread Fatigue Damage, as a structure which has the characteristics of similar features operating at similar stresses where structural capability could be affected by similar cracking. The well-publicized 1988 incident of the Aloha Airlines Boeing 737, which lost a large section of fuselage structure in flight, ushered in the era of research into ageing aircraft. This incident was caused by a collinear series of fatigue cracks which suddenly linked to form a single critical crack, leading to the catastrophic failure. At the time of the Aloha incident, a large number of relatively high-life military aircraft were in service, mainly in the roles of air transport, air-to-air refueling and maritime reconnaissance. Maintaining the structural integrity of these aircraft in prolonged service requires consideration to be given to inspections for detecting possible multiple damage in its various forms: 'Multi-site' damage (MSD) occurs mainly on neighbouring elements (lines of attachment holes, for example) or as a result of a fabrication surface damage (a long, continuous, scratch, for example). Their coalescence can lead to a sudden loss of residual strength. The concept of 'resistance to damage' implies structures which are able to tolerate the presence of cracked elements by ensuring that cracks are slowly propagated and to tolerate the presence of broken elements by providing load path redundancy. On this basis, the strength of the remaining undamaged structure must be sufficient to ensure safety in flight during a specified operating period. The role of Damage Tolerance is to assure structural integrity through in-service directed inspections of critical structures.
| Author | : |
| Publisher | : |
| Total Pages | : |
| Release | : 1995 |
| Genre | : |
| ISBN | : |
| Author | : |
| Publisher | : |
| Total Pages | : 253 |
| Release | : 1997 |
| Genre | : |
| ISBN | : |
The effect of corrosion and widespread fatigue damage (WFD) on the structural integrity of USAF aging aircraft could be detrimental to aircraft safety, readiness, and R & M (Reliability & Maintainability) costs. However, with the development and validation of appropriate structural life analysis tools and the supporting data, the effect of corrosion and WFD can be evaluated and therefore managed. But first, the supporting data will need to identify those structural elements which could cause a reduction in aircraft safety, readiness, or R & M when subject to corrosion or fatigue damage. The USAF aircraft fleets selected for consideration included the C/KC-135 Stratotanker, E-8C Joint STARS, C-9A/C Nightingale, C-130 Hercules, and C-5A/B Galaxy. The overall objective is to create a database, which is useful in identifying trends for the occurrence of corrosion and fatigue cracking damage to airframe Principal Structural Elements (PSEs). The database assembled under this effort contains individual records of inspection Reports and Repair Orders which have been obtained from standardized USAF damage and repair recording systems (such as OACIS, AIRS, REMIS, AND AFMC202) and from other USAF programs funded to collect specific airframe damage and repair records. This database is not intended to contain all the data, which might be used in a structural integrity evaluation, but it can be used to identify PSEs, which may need further consideration of their structural integrity capability. The trends developed provide real and repeatable evidence to assist in focusing improvement efforts where the largest gains can be made. The results from this project estimate the extent of corrosion and fatigue damage, which exists in the selected USAF aircraft systems. The Pareto trend format is used often to report the results as database record counts in decreasing order grouped by PSE type, location, and the defect type/severity.
| Author | : Paul W. Tan |
| Publisher | : |
| Total Pages | : 10 |
| Release | : 2003 |
| Genre | : |
| ISBN | : |
A methodology to assess the development of widespread fatigue damage (WFD) and its effect on the residual strength of aircraft structure has been developed. The three major components of the methodology are crack initiation, crack growth and linkup, and residual strength. The crack initiation methodology uses experimentally generated equivalent initial flaw size (EIFS) data and an analytical closure model to determine initial flaw sizes and distribution for multiple-site cracking. The crack-tip opening angle (CTOA) and the T* integral, and plastic zone touch (PZT) criteria were used to predict crack growth and linkup.
| Author | : Robert S. Piascik |
| Publisher | : |
| Total Pages | : 20 |
| Release | : 1994 |
| Genre | : |
| ISBN | : |
| Author | : National Research Council |
| Publisher | : National Academies Press |
| Total Pages | : 124 |
| Release | : 1997-09-30 |
| Genre | : Technology & Engineering |
| ISBN | : 0309174473 |
Many of the aircraft that form the backbone of the U.S. Air Force operational fleet are 25 years old or older. A few of these will be replaced with new aircraft, but many are expected to remain in service an additional 25 years or more. This book provides a strategy to address the technical needs and priorities associated with the Air Force's aging airframe structures. It includes a detailed summary of the structural status of the aging force, identification of key technical issues, recommendations for near-term engineering and management actions, and prioritized near-term and long-term research recommendations.
| Author | : Air Force Flight Dynamics Laboratory (U.S.) |
| Publisher | : |
| Total Pages | : 924 |
| Release | : 1971 |
| Genre | : Airframes |
| ISBN | : |
The document is comprised of papers presented at the Air Force Conference on Fatigue of Aircraft Structures and Materials, sponsored by the Air Force Flight Dynamics Laboratory (AFFDL) and the Air Force Materials Laboratory (AFML), Air Force Systems Command. The purpose of the Conference was to discuss technological advancements in fatigue and fracture theory. The Conference was comprised of ten technical sessions (including two panel discussions) entitled 'The Role of Materials in Structures'; 'Fundamentals I + II'; 'Criteria'; 'Fracture I + II'; 'Phenomena I + II'; 'Analysis'; 'Design and Service Experience'. A total of fifty-six technical papers were presented.
| Author | : |
| Publisher | : |
| Total Pages | : 0 |
| Release | : 1999 |
| Genre | : |
| ISBN | : |
This report summarizes research dealing with analyzing the effects of widespread fatigue damage on aircraft structural integrity. Results are described for determining how cracks nucleate by corrosion, fatigue, or fretting fatigue, and once formed, grow, coalesce and lead to final fracture. The research is conducted in the context of the aging aircraft issue, which focuses on determining procedures for ensuring the continued safety of aircraft that operate beyond their original design lifetimes.
| Author | : J. R. Gebman |
| Publisher | : Rand Corporation |
| Total Pages | : 84 |
| Release | : 2009 |
| Genre | : History |
| ISBN | : |
Over the next 20 years, the further aging of already-old aircraft will introduce challenges and issues for aircraft operators. The technical challenges relate to structures, propulsion, and systems. The institutional challenges include limitations on independent verification of fleet status and future condition and on information needed for engineering analyses including risk assessment, and an overall scarcity of resources.
