Flight simulation fatigue crack growth testing of aluminium alloys: Specific issues and guidelines

Flight simulation fatigue crack growth tests are necessary for verification of aircraft damage tolerance analyses and crack growth prediction methods, and also for comparing candidate materials for aircraft structural applications. However, such tests involve complicating issues that have emerged from many investigations on aluminium alloys...

Fractographic and microstructural analysis of fatigue crack growth in Ti-6Al-4V fan disc forgings

The constant amplitude and flight simulation (TURBISTAN) fatigue crack growth behaviour of Ti-6A1-4V fan disc forgings tested in the AGARD engine disc cooperative test programme was investigated by fractographic and microstructural analysis. The crack growth curve shapes and fractographic characteristics were similar. Transitions in the fatigue...

Damage tolerance and durability evaluation of aluminium-lithium alloys

New impetus to continued use of alximinium alloys in major structural areas of aircraft has been given by the development of aluminium-lithium alloys. However, qualification of these new materials for service requires extensive testing and evaluation, preferably in international cooperative programmes. The evaluation of aluminium-lithium alloys...

Corrosion fatigue crack arrest in aluminium alloys

The economic life of airframes is largely determined by widespread initiation and growth of fatigue cracks at low stress intensities. Any factor reducing the low stress intensity fatigue damage rate could, if controllable, increase the structural durability. One such factor is corrosion fatigue crack arrest. Corrosion product build-up within a...

Engineering property comparisons of PM and IM aluminium alloy forgings

Engineering properties of the PM alloy 7091-T7E69 and the IM alloys 7075-T73, 7175-T736, 7010-T736 and 7050-T736 were compared. The properties considered were strength, fracture toughness, fatigue strength, fatigue crack propagation resistance under constant amplitude and spectrum loading, stress corrosion crack initiation and propagation...

Non-destructieve bepaling van gewaseigenschappen met behulp van multispectrale scanning

The spectral distribution of radiation reflected by crops in the visible light region and the near infrared contains information concerning crop structure and the optical properties of the leaves and the bounding soil. Non-destructive determination on remote distance of crop properties by means of the measured spectral distribution of reflected...

An investigation of crack resistance in face sheets of sandwich panels

Sandwich panels provided with a central saw cut in one face layer were fatigue tested to study crack growth up to a predetermined length. Static residual strength was determined subsequently. Crack growth rates and residual strength are compared with similar data for face sheet material. An increased resistance against both stable fatigue crack...