The Experts below are selected from a list of 84 Experts worldwide ranked by ideXlab platform
Richard O. Claus - One of the best experts on this subject based on the ideXlab platform.
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Fabry–Perot fiber-optic sensors in Full-Scale Fatigue Testing on an F-15 aircraft
Applied Optics, 1992Co-Authors: K.a. Murphy, Ashish M. Vengsarkar, Michael F. Gunther, Richard O. ClausAbstract:We report results from fiber-optic-sensor field tests on an F-15 aircraft mounted within a Full-Scale test frame for the purpose of Fatigue Testing. Strain sensitivities of the order of 0.01 μm/m have been obtained.
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Fabry-Perot fiber-optic sensors in Full-Scale Fatigue Testing on an F-15 aircraft
Proceedings of SPIE - The International Society for Optical Engineering, 1991Co-Authors: K.a. Murphy, Ashish M. Vengsarkar, Michael F. Gunther, Richard O. ClausAbstract:We report results from fiber optic sensor field tests on an F-15 mounted within a Full-Scale test frame for the purpose of Fatigue Testing at the Structures Test Facility, Wright Patterson Air Force Base, Ohio. Static and dynamic loading data obtained using multiple extrinsic Fabry- Perot fiber optic sensors is presented. The output fringes from two quadrature phase shifted Fabry-Perot sensors were linearized using computerized software. The results compare well with data obtained from conventional strain gauges located adjacent to the fiber optic sensors. Strain sensitivities on the order of 0.01 μ/m were observed.
Keisuke Kumagai - One of the best experts on this subject based on the ideXlab platform.
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Full Scale Fatigue Testing for Mitsubishi Regional Jet
ICAF 2019 – Structural Integrity in the Age of Additive Manufacturing, 2020Co-Authors: Koji Setta, Toshiyasu Fukuoka, Kasumi Nagao, Keisuke KumagaiAbstract:Mitsubishi Aircraft Corporation is performing the Full-Scale Fatigue Testing (FSFT) for Mitsubishi Reginal Jet (MRJ) type certification. Main objective of this test is to show freedom from wide spread Fatigue damage (WFD) during the life of aircraft and establish Limit of Validity (LOV). Prior to the test, WFD susceptible structures are defined based on the stress distributions and structure configurations, and they are fully covered by this test. Test duration of FSFT is 240,000 flights (3 × DSG of 80,000 flights). The flight-by-flight loading spectrum is newly designed for MRJ and its loads occurrence data was verified by flight test data. Furthermore, to reduce the test duration, low loads omission was applied based on the results of some spectrum verification tests. During Fatigue test, scheduled inspection consistent with MRJ maintenance program is planned.Since the main objective of FSFT is no WFD substantiation, no artificial crack is introduced during FSFT. Therefore, damage tolerance evaluation (i.e. crack growth analysis validation) is separately conducted by sub-component level Testing. For example, damage tolerance substantiation for fuselage structure was performed by using curved panel test facility. This facility can simulate the pressurization load with axial load and their loading sequence can be customized for each test. Major detail design points of fuselage structure such as the lap/butt-joint, cut-out structure and repaired structure are individually evaluated by this type of tests. Based on the test results, potential Fatigue critical locations and crack growth behaviors are efficiently investigated, and they significantly contribute to the crack growth analysis validation necessary for CFR/CS 25.571 compliance.
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Full Scale Fatigue Testing for Mitsubishi Regional Jet
ICAF 2019 – Structural Integrity in the Age of Additive Manufacturing, 2019Co-Authors: Koji Setta, Toshiyasu Fukuoka, Kasumi Nagao, Keisuke KumagaiAbstract:Mitsubishi Aircraft Corporation is performing the Full-Scale Fatigue Testing (FSFT) for Mitsubishi Reginal Jet (MRJ) type certification. Main objective of this test is to show freedom from wide spread Fatigue damage (WFD) during the life of aircraft and establish Limit of Validity (LOV). Prior to the test, WFD susceptible structures are defined based on the stress distributions and structure configurations, and they are fully covered by this test. Test duration of FSFT is 240,000 flights (3 × DSG of 80,000 flights). The flight-by-flight loading spectrum is newly designed for MRJ and its loads occurrence data was verified by flight test data. Furthermore, to reduce the test duration, low loads omission was applied based on the results of some spectrum verification tests. During Fatigue test, scheduled inspection consistent with MRJ maintenance program is planned.
K.a. Murphy - One of the best experts on this subject based on the ideXlab platform.
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Fabry–Perot fiber-optic sensors in Full-Scale Fatigue Testing on an F-15 aircraft
Applied Optics, 1992Co-Authors: K.a. Murphy, Ashish M. Vengsarkar, Michael F. Gunther, Richard O. ClausAbstract:We report results from fiber-optic-sensor field tests on an F-15 aircraft mounted within a Full-Scale test frame for the purpose of Fatigue Testing. Strain sensitivities of the order of 0.01 μm/m have been obtained.
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Fabry-Perot fiber-optic sensors in Full-Scale Fatigue Testing on an F-15 aircraft
Proceedings of SPIE - The International Society for Optical Engineering, 1991Co-Authors: K.a. Murphy, Ashish M. Vengsarkar, Michael F. Gunther, Richard O. ClausAbstract:We report results from fiber optic sensor field tests on an F-15 mounted within a Full-Scale test frame for the purpose of Fatigue Testing at the Structures Test Facility, Wright Patterson Air Force Base, Ohio. Static and dynamic loading data obtained using multiple extrinsic Fabry- Perot fiber optic sensors is presented. The output fringes from two quadrature phase shifted Fabry-Perot sensors were linearized using computerized software. The results compare well with data obtained from conventional strain gauges located adjacent to the fiber optic sensors. Strain sensitivities on the order of 0.01 μ/m were observed.
Kyle Graham - One of the best experts on this subject based on the ideXlab platform.
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Full-Scale Fatigue Testing from a Structural Analysis Perspective
ICAF 2019 – Structural Integrity in the Age of Additive Manufacturing, 2020Co-Authors: Derk Daverschot, Paul Mattheij, Mathias Renner, Yudi Ardianto, Manuel Araujo, Kyle GrahamAbstract:Generally speaking, Full-Scale Fatigue tests are used to demonstrate ‘Means of Compliance’ (MoC) for Type Certification. Aircraft are designed in accordance with Fatigue and damage tolerance requirements; the main purpose of the Fatigue test being to provide the physical evidence necessary to validate design assumptions.Located at the top of the test pyramid, these tests come with significant investment. The test objective is therefore not only limited to compliance with regulations, but also aims to obtain highly important experience of the airframe providing significant benefit to future applications.This paper presents the structural analysis view of Full-Scale Fatigue Testing, which drives large parts of the test definition, execution, exploitation and use of test outcomes. Evolution of the general Fatigue test approach, alignment of Fatigue requirements with test execution and exploitation of the test results for Airbus aircraft is explained. Finally, the paper also aims to capture details regarding future development of Full-Scale Fatigue Testing.
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Full-Scale Fatigue Testing from a Structural Analysis Perspective
ICAF 2019 – Structural Integrity in the Age of Additive Manufacturing, 2019Co-Authors: Derk Daverschot, Paul Mattheij, Mathias Renner, Yudi Ardianto, Manuel Araujo, Kyle GrahamAbstract:Generally speaking, Full-Scale Fatigue tests are used to demonstrate ‘Means of Compliance’ (MoC) for Type Certification. Aircraft are designed in accordance with Fatigue and damage tolerance requirements; the main purpose of the Fatigue test being to provide the physical evidence necessary to validate design assumptions.
Othman Al-khudairi - One of the best experts on this subject based on the ideXlab platform.
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Full-Scale Fatigue Testing of a Wind Turbine Blade in Flapwise Direction and Examining the Effect of Crack Propagation on the Blade Performance.
Materials, 2017Co-Authors: Othman Al-khudairi, Homayoun Hadavinia, Christian Little, Gavin K Gillmore, Peter Greaves, Kirsten DyerAbstract:In this paper, the sensitivity of the structural integrity of wind turbine blades to debonding of the shear web from the spar cap was investigated. In this regard, modal analysis, static and Fatigue Testing were performed on a 45.7 m blade for three states of the blade: (i) as received blade (ii) when a crack of 200 mm was introduced between the web and the spar cap and (iii) when the crack was extended to 1000 mm. Calibration pull-tests for all three states of the blade were performed to obtain the strain-bending moment relationship of the blade according to the estimated target bending moment (BM) which the blade is expected to experience in its service life. The resultant data was used to apply appropriate load in the Fatigue tests. The blade natural frequencies in flapwise and edgewise directions over a range of frequency domain were found by modal Testing for all three states of the blade. The blade first natural frequency for each state was used for the flapwise Fatigue tests. These were performed in accordance with technical specification IEC TS 61400-23. The Fatigue results showed that, for a 200 mm crack between the web and spar cap at 9 m from the blade root, the crack did not propagate at 50% of the target BM up to 62,110 cycles. However, when the load was increased to 70% of target BM, some damages were detected on the pressure side of the blade. When the 200 mm crack was extended to 1000 mm, the crack began to propagate when the applied load exceeded 100% of target BM and the blade experienced delaminations, adhesive joint failure, compression failure and sandwich core failure.
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Structural performance of horizontal axis wind turbine blade
2014Co-Authors: Othman Al-khudairiAbstract:The power output from a wind turbine is proportional to rotor swept area and as a result in the past 30 years continuous effort has been made to design larger blades. In this period, the blade length has been increased about 10 times since 1980s to present time. With the longest blade currently measuring more than 100m in length, wind turbine blade designers and manufacturers face enormous challenges to encounter the effect of increased weight and other loads on Fatigue durability of the blade. Wind turbine blades are mainly made from glass fibre reinforced plastic (GFRP) composite. materials. As a result, in the design of various parts of wind turbine blades such as the shear web, spar cap and the aerofoil the Fatigue behaviour of F RP materials is required. The performance of these parts as well as the adhesively bonded joint under Fatigue loading is crucial for structural integrity of a long lasting blade. During operation, delamination can initiate and propagate shortening blade life; hence, characterisation of failure envelope of GFRP laminates under different loading mode is necessary. In this regard in this project, quasi-static tests were carried out to find mode 1, mode 11 and mixed mode I/11 delamination fracture toughness using DCB, ENF and MMB tests and the fracture envelope was established for various mode mixity. In the next stage, the stress-lifetime (S-N) diagrams of the GFRP was studied. Fatigue-life experiments on three different types of loading, i.e. tension-tension at R=0.1, 0.5, tension- compression at R=-1 and compression-compression at R=2 and R=10 were performed. From the results of S-N diagrams, the constant life diagrams (CLD) for 90 degree and 0 degree fibre directions were constructed. CLD diagrams are useful for prediction of Fatigue lifetime for loading condition that no experimental data available. The analysis of delamination crack propagation under cyclic loading was next area of the research. The onset life and propagation delamination crack grth of 0//0 interface of GR P laminate in mode I loading using DCB specimens was investigated and the Gm. from the onset life test was determined. From the fitted curve to mode I experimental propagation data the Paris’ law coefficient for the laminated GFRP in mode I was determined. The mode II Fatigue crack growth in laminated 0//0 GFRP material was also investigated using ENF specimens. The Fatigue behaviour in this mode is analysed based on application of Paris’ law as a function of energy release rate for mode II loading. From the fitted curve to experimental data, the Paris’ law coefficient for the laminated GFRP in mode II was determined. The effect of Fatigue delamination growth on fracture surface was studied by fractography analysis of SEM images of fracture surfaces. Studying the behaviour of GFRP under cyclic loading and delamination under static and dynamic load led to Full-Scale Testing of wind turbine blade to establish damage tolerance of the blade under cyclic loading. The sensitivity of wind turbine blade to damage has considerable interest for turbine operators and manufacturers. For Full-Scale Fatigue Testing, calibration test and modal analysis of a 45.7m blade has been done and moment-strain diagram and natural frequencies of the blade were obtained. Next, the blade sensitivity to damage under Fatigue loading was investigated. The blade has been damaged intentionally by initially inserting a crack of 0.2m between the shear web and spar cap and later it was extended to 1m. The effect of these damages on the modal shape, natural frequencies and strains at various locations of the blade were investigated. The damaged blade Fatigue tested, the structural integrity and growth of damage were monitored, and the results were discussed. Finally for the improvement of delamination resistance for joints between spar beam and aero-shell stitching method was used. T-beam and box beam joint were chosen as the platform for Testing the stitching effect on the delamination. Various pattern of stitching was applied and the optimum pattern was determined.
