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Schijve, J. (author), Jacobs, F.A. (author), Tromp, P.J. (author)Comparative flight-simulation tests on four types of joints of 2024- T3 sheet material were carried out with and without application of the penetrant LPS-3. Types of joints were douhle strap joint with hi-lok bolts, asymmetric strap joint, lap joint with countersunk rivets and lap joint with dimpled holes. Observations on slip during the fatigue...report 1977
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Jacobs, F.A. (author), Schijve, J. (author), Tromp, P.J. (author)Fatigue tests under flight-simulation loading have been performed on unnotched Alclad 2024-T3, anodised 2.0 mm thick sheet specimens, manufactured according to several machine-shop processes applied in the air craft industry. From the results it appears that milling is preferable to stamping. Rounding off the edges is also advantageous. The...report 1977
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Schijve, J. (author), Jacobs, F.A. (author), Tromp, P.J. (author)Flight-simulation tests based on a standardized gust load spectrum were carried out in normal air, very dry air and salt water. Specimen thicknesses were t = 2 mm and t = 10 mm, mean stress in flight was 70 or 55 MN/m². In all cases a significant effect of the environment was found. Fatigue lives for t = 10 ram were much shorter than for t = 2...report 1976
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Schijve, J. (author), Jacobs, F.A. (author), Tromp, P.J. (author)Flight-simulation tests were carried out on sheet specimens notched "by an open hole (Kt = 2.66). The material was 2024-T3 in three conditions; Alclad, bare and chemically milled. The crack initiation period and the crack propagation period were considerably shorter for the Alclad material. The significance of the cladding, both for constant...report 1976
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Schijve, J. (author), Jacobs, F.A. (author), Tromp, P.J. (author)Tests were carried out on open-hole specimens, lugs and riveted strap joints of 2024-T3 and 7075-T6 materials. The effects of design stress level, truncating high-amplitude gust loads and omitting low-amplitude gust cycles were stuaied. Observations of the open-hole specimens include data on crack initiation, crack closure and damage increments....report 1974
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Schijve, J. (author), Jacobs, F.A. (author), Tromp, P.J. (author)Specimens of 2024-T3 and 7075-T6 were tested at 10, 1 and 0.1 cps. Values of mean stress in flight were 10.0, 8.5, 7.0, 5.5 and 4.0 kg/mm(2). The analysis of the results bears upon the frequency effect and its significance for inspection periods in service, the effect of stress level, a comparison between the two alloys, the prediction of crack...report 1973
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Schijve, J. (author), Jacobs, F.A. (author), Tromp, P.J. (author)Crack propagation was studied in 2024-T3 Alclad sheet specimens under two types of random loading and under program loading with a short period and a long period. In the program tests Lo-Hi, Lo-Hi-Lo and Hi-Lo sequences were employed. The loads were based on a gust spectrum. The crack rates were about the same under random loading and program...report 1971
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Schijve, J. (author), Jacobs, F.A. (author), Tromp, P.J. (author)Random flight-simulation tests were carried out in a similar way as in a previous investigation (NLR TH 68117) but now at lower stress levels. Truncation of the high gust loads again had a predominant effect. Increasing the truncation level considerably decreased the crack propagation rate.report 1969
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Schijve, J. (author), Jacobs, F.A. (author), Tromp, P.J. (author)A large number of flight-simulation tests were carried out on sheet specimens of 7075-T6 and 2024-T3 clad material. A gust load spectrum was adopted and a flight-by-flight loading was applied. The investigation is essentially concerned with macro-crack propagation though a few exploratory tests were conducted on the crack nucleation period. The...report 1968