The Future of the Dutch Environmental Testing Market

The environment is an important part of the life for most organisms, including humans. Since its quality is integral for social welfare, ensuring and maintaining a high environmental quality is essential. The environmental testing market is dedicated to the testing of the three main components of environment: soil, water, and air. Since the...

Developing thermal testing methods for a locomotion system of a Phobos rover

In 2024, a rover will leave Earth on a daring mission to explore Phobos, one of the two moons of Mars. Phobos has a severe thermal environment, with surface temperatures ranging from -153 °C to +57 °C and an 8-hour diurnal cycle. This work focuses on validating the performance of the locomotion system of the Mars Moon eXploration (MMX) rover....

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 effect of the environment on the fatigue properties of ARALL-3

The effect of the environment on the fatigue behaviour and residual strength of ARALL-3 has been studied using three types of specimens, varying in structural complexity. In addition to the reference ambient air condition, specimens were aged and/or fatigue loaded in hot/humid air or in sump tank fluid. Environmental fatigue loading of door...

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,...

Patch repair of corroded aircraft skin areas

Environmental conditions in Europe are conducive to corrosion attack of aircraft structures. In military aircraft corrosion problems occur especially at countersunk fastener holes. The corrosion is generally removed by grinding. A limited amount of material removal is specified by the aircraft manufacturers, but it is sometimes necessary to...

Flight simulation fatigue crack propagation in metal/carbon-epoxy laminates

Flight simulation fatigue crack propagation tests with gust spectrum loading were carried out on laminates of (i) aluminium alloy 2024-T3/carbon-epoxy, (ii) aluminium alloy 7475-T761/carbon-epoxy and (iii) titanium alloy Ti-6Al-4V/carbon-epoxy with nominal weight savings of 30% and 40% as compared to equivalent 2024-T3 Alclad and 7475-T761...

Flight simulation environmental fatigue crack propagation in 2024-T3 and 7475-T761 aluminium

Flight simulation fatigue crack propagation tests on 202U-T3 and 7475-T761 aluminum alloy sheet were carried out using a gust spectrum representative of the load history of an under wing skin in a transport aircraft. The investigation included tests at several design stress levels and in environments of laboratory air and air plus water spray....

Testing of coatings and materials for jet engine components in simulated operational environments

Military aircraft flying low level missions in Western Europe encounter a very different environment from that in most of the United States. Industrial pullution causes atmospheric moisture to be highly acid, and the corrosion rate of jet engine components is greatly increased, with consequent high maintenance costs. To help combat this problem...

Environmental fatigue crack propagation in metal/composite laminates: interim report no. 1

Plight simulation fatigue crack propagation tests with gust spectrum loading were carried out on 2024-T3/carbon-epoxy, 7475-T761/carbon-epoxy and Ti-6Al-4V/carbon-epoxy laminates with nominal weight savings of 30% as compared to equivalent 2024-T3 panels. The performance of the 2024-T3/ carbon-epoxy laminates was much superior to those of the...

The influence of texture on environmental fatigue crack propagation in titanium alloys

Environmental fatigue crack propagation in Ti-6A1-4V sheet: Revised Edition

A study was made of environmental fatigue crack propagation in 2.5 mm thick Ti-6A1-4V sheet conforming to AMS 4911, and 2.2 mm thick IMI 3l8 conforming to BS TA 10. The environments were dry argon, normal air, distilled water and 3.5 ^ aqueous NaCl. There were three alloy/orientation combinations: Ti-6A1-4V L-T, IMI 3l8 L-T and IMI 318 T-L. Test...