Further evaluation of the Ascor test for stress corrosion testing of aluminium alloys

In 1991 a simple automated stress corrosion testing method called the ASCOR (Automated Stress corrosion Ring) test was developed to test aluminium alloys according to ASTM specification G49. The present investigation concentrated on evaluating two aspects of the test method: The SCC initiation criterion (2 % load decrease). The possibility of...

Re-analysis of European flight load data

The ASCOR test: a simple automated method for stress corrosion testing of aluminium alloys

Alternate immersion stress corrosion testing according to ASTM specification G44 has proven to be representative for aluminium alloys in natural environments resembling the actual environmental conditions for aircraft. A simple automated stress corrosion testing method called the ASCOR (Automated Stress COrrosion Ring) test was developed to test...

Outdoor corrosion testing of aluminium-lithium alloys

Outdoor corrosion and stress corrosion tests were conducted on Al-Li plate and sheet materials for 3 and almost 5 years respectively. The results can be summarized as follows: Corrosion: Peak aged XXXA-T651 (8090-T651) exhibited greater exfoliation corrosion resistance than 2024-T351 and 2324-T39 plate. 2091-T3 and 2024-T3 sheet were found to be...

Long-term outdoor stress corrosion testing of overaged 7000 series aluminium alloys

Long-term outdoor stress corrosion tests were executed on overaged 7000 series aluminium alloy plate and forgings. Plate material of the alloys 7010-T7651, 7010-T7451 and 7075-T7351 exhibited an excellent resistance to SCC. PM alloy X7091-T7E69 forgings combined a higher strength with superior SCC resistance as compared to IM alloy forgings. The...

Statistical properties of atmospheric turbulence relevant to the calculation of airplane loads

Measured time histories of atmospheric turbulence have been analysed. Distribution functions and exceedance curves of the turbulence and its derivative are presented. The load exceedance curves of various mathematical airplane models due to these turbulence patches have been calculated. Deviations of the properties of these patches from the...

Parameter identification results of tests in non-steady symmetric flight with the Hawker Hunter Mk VII

This report presents the parameter identification results derived from data recorded during non-steady symmetric flight test manoeuvres with the Hawker Hunter Mk VII laboratory aircraft. This flight test program was executed in co-operation with the Department of Aerospace Engineering of the Delft University of Technology. The reproducibility of...

Vertical accelerations of a large aircraft during landing and taxiing

Vertical accelerations diiring landing and taxiing have been extracted from the AIDS-data base. This data base contains fatigue related data derived from the AIDS-system, used by KSSU-Boeing 747 operators. Results are presented axid compared with similar data from other sources.

Influence of environments on constant displacement stress corrosion crack growth in high strength aluminium alloys

An experimental investigation was carried out into the applicability of various corrosive environments for stress corrosion crack propagation testing of high strength aluminium alloys using double cantilever beam specimens. Testing under atmospheric conditions was used as a reference. It was found that stress corrosion crack growth under...

Stress corrosion crack initiation testing of high strength aluminium alloys using tuning fork type specimens

An experimental investigation was carried out into the applicability of various corrosive environments for stress corrosion crack initiation testing of high strength aluminium alloys using constant strain loaded tuning fork type specimens. The effect of surface preparation was also involved. The most important findings were that salt-chromate...

Some methods for the derivation of taxying loads for undercarriages with linear or nonlinear properties.

Methods that are used or probably could be used for the establishment of taxying loads are presented and discussed. The methods are straightforward for undercarriages with linear properties. For undercarriages with nonlinear properties methods based on the use of equivalent gains are promising, but still have to be verified.

Some investigations on the notching procedtire used in shaker tests on satellites

The notching procedure as used in the shaker test on a satellite is critically examined. In stead of the notching procedure an alternative test set-up, in which the dynamic interaction between launcher and spacecraft is taken into account, has been proposed and investigated for a simple model of launcher and satellite. Using this test set-up the...

Investigation on a passenger ride-comfort improvement system with limited control surface actuator performance for a flexible aircraft

For the low wing-loading aircraft, considered in this investigation, vertical acceleration appeared to be an important factor concerning passenger comfort. To reduce vertical motions, a ride-comfort improvement system was introduced. Determination of parameters of the system, like gains and allowable performance limitations, required analog...