Variation in load experience: A re-analysis of Fokker F27 and Foker F28 operational acceleration data

Fatigue meter data obtained during operational flights of Fokker F27 and Fokker F28 aircraft were re-processed and analyzed to study the variation in load experience between different aircraft of the same type. The Data covered about 470000 flights, made by 101 aircraft of 51 different operators. A simple algorithm was developed to quantify the...

Variability of fatigue crack growth properties for 2024-T3 aluminium alloy

Discussions between D-BAA and the NLR have shown that significant variability in fatigue crack growth properties is possible for the industry standard damage tolerant aluminium alloy, 2024-T3 sheet. This is important for two reasons: (1) design assumptions and (2) comparisons of different candidate materials, such as 6013-T6, with 2024-T3....

Damage assessment and preservation of an Egyptian silver vase (300 - 200 B.C.)

An Egyptian metal vase from the Ptolemaic period was investigated metallurgically and fractographically. The metal is nearly pure silver, and chemical analysis indicates it was obtained from the cupellation of lead. Despite its high purity (in archaeological terms) the metal is severely cracked and embrittled, with fractures mainly along grain...

Aircraft corrosion and fatigue damage assessment (USAF ASIP Publication)

This paper reviews currently available information on corrosion and fatigue in aircraft as a background to discussing the assessment of corrosion and fatigue damage. The main topics are: - aircraft operating environments and loads - corrosion - fatigue - corrosion and fatigue - corrosion and fatigue damage assessment. Aircraft structures are...

A damage tolerance study conducted with structure relevant specimens

A preliminary investigation is reported of the development of a Structure Relevant (SR-) specimen, which maintains the essential features of a stiffened panel configuration, in order to study damage growth behavior at limited cost. Several SR-specimens were fabricated, damage was applied, either through impacts or by the insertion of artificial...

Monitoring load experience of individual aircraft

Paper presented at the 17th ICAS Congress, Stockholm, September 1990. The actual service load experience of aircraft may differ appreciably from design assumptions. The necessity to monitor service loads is generally recognized now for military aircraft. This paper starts with a general review of the overall life management procedure commonly...

Delamination growth in improved carbon composites under constant amplitude fatigue loading

Constant amplitude tension-compression fatigue tests were performed on notched (± 45, 02, 90, 02)s coupon specimens of the composite systems T300/F593, T400H/6376, T800H//5245C and IM6/APC-2. Delamination damage growth as a function of the number of fatigue cycles was determined using the ultrasonic C-scan technique. Considering the resistance...

Prediction of fatigue crack growth

As an introduction the practical significance of fatigue crack growth life prediction is related to the service life, the inspection period and the fracture control requirements. Then different aspects of fatigue crack growth in metallic materials are discussed in more detail. Important effects such as chemical environment, short cracks, crack...