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Anonymus, A. (author)Piping and hydraulic fracturing (heave) are phenomena which can threaten the stability of flood defences. These phenomena can arise when, in the case of large-scale hydraulic head, particles of soil in layers of earth which are susceptible to erosion are transported underneath the flood defence by the seepage flow, as a consequence of which...report 1999
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Schra, L. (author)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...report 1996
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Wanhill, R.J.H. (author), Boogers, J.A.M. (author), Huisman, H.N. (author), Ottens, H.H. (author)In 1995 an air supply manifold support rod from a high-performance turbofan engine failed by bending fatigue. The rod material was Inconel 718, operating at about 550° in an air environment. Diagnostic aspects of the failure (fatigue in bending, Stage I and Stage II fatigue fracture characteristics, and interference colours due to fracture...report 1996
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Wanhill, R.J.H. (author), Leenheer, R. (author), Steijaert, J.P.H.M. (author), Koens, J.F.W. (author)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...report 1995
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Wanhill, R.J.H. (author)This report contains the overhead sheets of a short course on fatigue and fracture of aerospace aluminium alloys, plus an annex in the form of a review paper.report 1994
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van der Hoeven, W. (author)The effect of cooling rate on some mechanical properties of APC-2/AS4 composite was investigated over the range between 1 and 70° C/min. Preconsolidated unidirectional laminates were reprocessed in a hot platen press at controlled cooling rates. Double Cantilever Beam specimens and End Notch Flexure specimens were used to determine the mode I...report 1993
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van Rijn, J.C.F.N. (author)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...report 1992
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Wanhill, R.J.H. (author)Sustained load fracture control is a problem of particular importance for manned spacecraft and orbital stations, owing to the long design lives and limited opportunities for repair. The current ESA approach Is based on screening out materials shown to be susceptible to stress corrosion cracking (SCC) from smooth specimen tests. This approach...report 1991
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Wanhill, R.J.H. (author), Schra, L. (author), 't Hart, W.G.J. (author)A comparison is made of the crack resistance (R-curve), fracture toughness and instability behaviour of candidate damage tolerant aluminiumlithium alloys, 2091 and 8090, and the widely used conventional 2024-T3 alloy. The 2091 alloy was in three heat treatment conditions, T8X, TX and TY, all artificially aged. The 8090 alloy was in the T81...report 1990
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- Chen, D. (author) report 1990
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Wanhill, R.J.H. (author)The opportunities for sustained load fracture control in spacecraft are indicated. Emphasis is given to verification by small-scale laboratory testing.report 1989
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Wanhill, R.J.H. (author), Schra, L. (author), 't Hart, W.G.J. (author)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...report 1989
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Wanhill, R.J.H. (author), Schra, L. (author)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...report 1988
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- van der Hoeven, W. (author) report 1988
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de Koning, A.U. (author)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...report 1987
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Lof, C.J. (author)Computer programs are described to be used for fracture control purposes. Crack growth lifetimes can be predicted for plane cracks in 3-D structures. Values for stress intensity (K-) distributions at crack fronts are derived from data being available from literature for a restricted number of simple configurations. For arbitrary configurations...report 1986
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de Koning, A.U. (author)This study deals with fracture mechanics aspects of mode 1 crack growth under montonically increasing (quasi-static) loads. Using the finite element method stable crack growth and the plastic deformation fields associated with this process are analyzed. A two parameter approach is proposed for a description of initiation and subsequent stable...report 1985
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Kolkman, H.J. (author)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...report 1985
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Schra, L. (author), 't Hart, W.G.J. (author)Engineering property comparisons have been made for plate material of the newly developed aluminium alloy 2324-T39 and the widely used alloy 2024-T351. The properties considered were: tensile strength, fracture toughness, notched fatigue strength, and the resistance to fatigue crack propagation under both constant amplitude and flight simulation...report 1984
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Wanhill, R.J.H. (author), Schra, L. (author)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...report 1983