The influence of testing parameters on stress corrosion crack growth in the high strength aluminium alloy 7010-T651

An interlaboratory testing programme to evaluate the rising displacement test for stress corrosion crack (SCO growth investigations was carried out within the framework of the "Measurements and Testing" programme of the European Community under BCR contract nr. MATI CT 930038. The contribution of the NLR to the project consisted of testing of...

The influence of starter notches on flight simulation fatigue crack growth

An investigation was made of the effect of starter notch geometry on flight simulation fatigue crack growth in three damage tolerant aluminium sheet alloys, 2024-T3, 2091-T84 and 8090-T81. Changing the starter notch geometry resulted in significant differences in initial nonstabilized fatigue crack growth behaviour. However, there was only a...

Stress distribution around a circular hole in a fibre metal laminate finite width plate specimen

The stress distribution in the vicinity of a notch is investigated as a first step towards a more fundamental understanding of the blunt notch behaviour of fibre metal laminates. The applicability of several analytical methodologies for determination of the stress distribution in the vicinity of a notch in a finite width plate is assessed in...

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...

The use of composite fracture models to describe the blunt notch behaviour of metal laminates

The blunt notch behaviour of metal laminates has mostly been described using concepts which were developed to describe the blunt notch behaviour of metals. In the current work the applicability of fracture models which were developed for composites to describe the blunt notch behaviour of metal laminates is assessed. It is shown that three...

A test plan for sustained load fracture control verification

An example test plan for sustained load fracture control verification is presented. Two sustained load fracture problems have been chosen: stress corrosion cracking of titanium alloy Ti-6Al-4V, and gaseous hydrogen embrittlement of the nickel-base superalloy Inconel 718. The plan is worked out in detail, including materials and heat treatments,...

Microstructural and fractographic analysis of fatigue crack propagation in 2024-T351 and 2324-T39

Differences in the fatigue crack propagation rates of 2024-T351 and 2324-T39 are explicable from differences in microstructures. The slope changes (transitions) in the crack propagation curves are probably associated with the plastic zone sizes being equal to certain microstructural dimensions. As a consequence of different chemical compostion...