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Koolloos, M.F.J. (author), ten Hoeve, H.J. (author), Grooteman, F.P. (author), de Koning, A.U. (author)
Multiple Site Damage (MSD) is a typical problem for ageing civil and transport aircraft, where the large number of fuselage pressure cycles may cause fatigue cracking at multiple rivet locations. The residual strength of a panel with a leading crack and MSD cracks is lower than that of a panel with the same leading crack but without MSD. This...
report 2001
document
de Koning, A.U. (author)
In this report a survey is given of recent research at NLR on damage tolerance analyses of aerospace structures and materials. The work was primarily done under contracts with the NRT (= Nationaal Ruimtevaart Technologie programma) and ESA (European Space Agency). The contributions of NRT are indicated.
report 1997
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de Koning, A.U. (author), Henriksen, T.K. (author)
Probably one of the most challenging problems in fracture mechanics is related to its application to fastener and joints. By nature, not only the quality such as material, manufacturing and mounting processes, of the fasteners are playing a role, but also the stiffness, surface conditions and geometry of the parts are to be considered. Moreover,...
report 1996
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de Koning, A.U. (author), Schra, L. (author)
In this report the experimental procedure is described and results are given of tests for verification of advanced crack growth prediction models. Testing involved constant amplitude fatigue loading at R = 0.1 and R = 0.5. In a similar test series loading was interrupted at regular intervals for application of overloads or overload/underload...
report 1994
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de Koning, A.U. (author), Henriksen, T.K. (author), ten Hoeve, H.J. (author)
Fatigue crack growth associated with cyclic (secondary) plastic flow near a crack front is modelled using an incremental formulation. A new description of threshold behaviour under small load cycles is included. Quasi-static crack extension under high load excursions is described using an incremental formulation of the R-(crack growth resistance...
report 1994
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Richmond, M.J. (author), de Koning, A.U. (author)
Utilising the NLR Stripyield cycle-by-cycle fatigue crack growth model a basic description of the time dependent effects associated with periods of constant load level has been added to model Fatigue-Creep interactions. An outline of the basic Creep model is given along with flow diagrams of the sub programs added to the Stripyield model. Other...
report 1993
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Laméris, J. (author), de Koning, A.U. (author)
This report contains the development plan of the NLR contributions to the ESTEC study: "Structural Integrity of Launchers - Part C". It describes the determination of the load transfer in and the stress intensity distribution of loaded metric bolts containing different types of fatigue cracks,
report 1993
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de Koning, A.U. (author), Richmond, M.J. (author)
At the NLR the CORPUS model was developed for prediction of fatigue crack growth under variable amplitude loading. In this document the different versions and areas of application are discussed. Problem areas in the applicability of the models are indicated and suggestions for improvement are made. In addition a Hybrid formulation is developed...
report 1992
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de Koning, A.U. (author)
At NLR models are developed for prediction of fatigue crack growth under variable amplitude loading. The models, computer programmes and specific areas of application are discussed. Results obtained using the software are compared with experimental data available for the same configurations. References for a more detailed description of models,...
report 1990
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de Koning, A.U. (author)
In this report aspects of crack growth under sustained loads in aerospace materials are considered. Some models developed for a description of processes affecting the crack growth rate are discussed. Relevant natural and Induced environments are summarized as well as the material behaviour observed under these conditions. In a separate section...
report 1988
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de Koning, A.U. (author), Dougherty, D.J. (author)
Applicability of rainflow counting to crack growth analysis of complex loading is discussed. The rainflow counting method can account for the effects of small and high loading cycles under spectrum loading conditions. A new incremental crack growth model which accounts for these effects is introduced. The model is compared with experimental...
report 1988
document
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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de Koning, A.U. (author), Schra, L. (author)
Crack growth prediction methods were evaluated and a preliminary selection was made of models that appear to be applicable to ESA space structures. In this report predictions based on the candidate models are verified by comparison with experimental results. Test configurations, materials and initial defects are specified as well as the load...
report 1986
document
de Koning, A.U. (author), Liefting, G. (author)
Presented at: The International Symposium on fatigue crack closure. May 1986, Charleston
report 1986
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de Koning, A.U. (author), Liefting, G. (author)
The crack opening behaviour of a fatigue crack in a centrally cracked panel was studied using a discretised version of the Dugdale and Barenblatt model. The effect of crack growth was also included. Results obtain ed for constant amplitude loading were in agreement with data reported in the open literature. The effect of application of single...
report 1986
document
de Koning, A.U. (author)
Crack growth prediction methods were evaluated and a preliminary selection was made of models that appear to be applicable to ESA space structures. In this report a plan is formulated for verification of the candidate models. Test configurations, materials and initial defects are specified as well as experimental procedures to be used for...
report 1985
document
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
document
de Koning, A.U. (author)
In part 1 of this study criteria were specified for evaluation and selection of crack growth models and computer programs for prediction of fatigue crack growth rates. In part 2 the criteria are used to compare different computer programs available to ESA. The programs involved are FLAGR04 (distributed by COSMIC), NASGRO (developed by NASA),...
report 1985
document
de Koning, A.U. (author)
Recently, ESA prepared "Fracture Control Guidelines" for STS (Space Transportation System) payloads to meet NASA requirements. In this study applicability of fracture mechanics principles to fatigue crack growth and failure is discussed. Different effects such as threshold, fracture toughness and load ratio and the behaviour of short cracks are...
report 1984
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van der Linden, H.H. (author), de Koning, A.U. (author), Lof, C.J. (author)
After a discussion of some aspects of aircraft design philosophy and the fatigue phenomenon, two analytical techniques for prediction of crack growth rates are described. The first method includes a model for prediction of fatigue crack growth in aluminium alloy sheet specimens subjected to service loading conditions. The second method involves...
report 1982
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