L. Brasche
Iowa State University
Publications 46
#1David J. EisenmannH-Index: 5
#2Darrel EnyartH-Index: 1
Last.L. BrascheH-Index: 8
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Magnetic particle inspection (MPI) has been widely utilized for decades, and sees considerable use in the aerospace industry with a majority of the steel parts being inspected with MPI at some point in the lifecycle. Typical aircraft locations inspected are landing gear, engine components, attachment hardware, and doors. In spite of its numerous applications the method remains poorly understood, and there are many aspects of that method which would benefit from in-depth study. This shortcoming i...
3 CitationsSource
#1Daniel J. BarnardH-Index: 11
#2Leonard J. BondH-Index: 5
Last.Stephen D. HollandH-Index: 14
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Abstract : Nondestructive evaluation plays a crucial role in the safety of flight, with an increasing importance as military fleet ages and the mission profile is expanded beyond the original design interest. The program completed by the Center for Nondestructive Evaluation at Iowa State University included development of new capabilities to quantify residual stress profiles in Al, Ti, and Ni alloys; expansion of simulation tools for eddy current, ultrasonics, and radiography; advances in probab...
#1Otto BuckH-Index: 15
#2R. B. ThompsonH-Index: 17
Last.D. D. PalmerH-Index: 4
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The ultrasonic interrogation of a partially contacting interface provides details on the contact topology. In this paper this information is used to deduce important mechanical properties of structures containing fatigue cracks and diffusion bonds as specific examples of such interfaces. The information is sufficient to determine the residual stress distribution in the wake of the crack. These residual stresses produce a stress intensity factor which, in part, shields the crack from the external...
#1Terrance C. Jensen (Iowa State University)H-Index: 2
#2Scott WendtH-Index: 2
Last.L. Brasche (Iowa State University)H-Index: 8
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Technical challenges exist with infrastructure that can be addressed by nondestructive evaluation (NDE) methods, such as detecting corrosion damage to reinforcing steel that anchor concrete bridge railings to bridge road decks. Moisture and chloride ions reach the anchors along the cold joint between the rails and deck, causing corrosion that weakens the anchors and ultimately the barriers. The Center for Nondestructive Evaluation at Iowa State University has experience in development of measure...
2 Citations
#1L. Brasche (Iowa State University)H-Index: 8
#1Stephen D. Holland (Iowa State University)H-Index: 14
#2Christopher Uhl (GE Aviation)H-Index: 4
Last.David J. Eisenmann (Iowa State University)H-Index: 5
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Abstract Vibrothermography, also known as Sonic IR and thermosonics, is a method for finding cracks through thermal imaging of vibration-induced crack heating. Due to large experimental variability and equipment which has, up to now, yielded mostly qualitative results, little data has been available to help quantify the vibrothermographic effect. This paper quantitatively evaluates the relationship between vibrothermographic crack heating, crack size, and vibrational stress in a series of tests ...
36 CitationsSource
#1R. B. Thompson (Iowa State University)H-Index: 17
#2William Q. Meeker (Iowa State University)H-Index: 38
Last.L. Brasche (Iowa State University)H-Index: 8
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The probability of detection (POD) of inspection techniques is a key input to estimating the lives of structural components such as aircraft engines. This paper describes work conducted as a part of the development of POD curves for the ultrasonic detection of synthetic hard alpha (SHA) inclusions in titanium aircraft engine forgings. The sample upon which the POD curves are to be based contains four types of right circular SHAs that have been embedded in a representative titanium forging, as we...
2 CitationsSource
#1Frank J. Margetan (Iowa State University)H-Index: 16
#2Nathaniel L. Richter (Iowa State University)H-Index: 2
Last.R. Bruce Thompson (Iowa State University)H-Index: 16
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Some prototype armor panels are fabricated from several layers of dissimilar material bonded together. These may include ceramics, graphite composites, fiberglass composites and rubber. The ultrasonic properties of these layers influence inspections for armor defects. In this paper we describe measurements of ultrasonic velocity, attenuation, sound beam distortion and signal fluctuations for the individual layers comprising one armor prototype. We then discuss how knowledge of these properties c...
3 CitationsSource
#1David J. Eisenmann (Iowa State University)H-Index: 5
#2L. Brasche (Iowa State University)H-Index: 8
Fluorescent penetrant inspection (FPI) is widely used in the aviation industry and other industries for surface‐breaking crack detection. As with all inspection methods, adherence to the process parameters is critical to the successful detection of defects. There is variety of lubricants and surface coatings used in the aviation industry which must be removed prior to FPI. Before the FPI process begins, components are cleaned using a variety of cleaning methods which are selected based on the al...
#1L. BrascheH-Index: 8
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Fluorescent penetrant inspection (FPI) is the most widely used global inspection method, playing a particularly important role in aviation. Given the contribution that reliable implementation of the FPI process can make to flight safety, the US Federal Aviation Administration (FAA) has funded a programme to assess the FPI parameters and their role in effective detection of typical flaws. Iowa State University's Center for NDE (CNDE) has led a team that includes many industry partners from the av...