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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Remote control digital photography and metrology are combined to accurately define optical efficiency problems in concentrating solar power (CSP) plants.
Concrete is a critical component of nuclear power plants; thus, its safety and reliability must be thoroughly examined throughout the life cycle of the structural system. During the life cycle of this infrastructure, monitoring of the concrete for signs of degradation should be performed through nondestructive evaluation (NDE). Ultrasonic measurements have been an industry standard for both surface and subsurface inspections. As such, Oak Ridge National Laboratory (ORNL) is developing advanced image reconstruction algorithms to overcome the limitations of traditional ultrasonic NDE methodologies. The results and discussion presented herein summarize the current state of the ultrasonic model–based iterative reconstruction (U-MBIR) algorithm developed at ORNL.
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Relative strengths of notched single-layer and multilayer stainless steel pressure vessels at cryogenic temperatures
Photographic production of a small-dot pattern of known geometry on the surface of a substrate for controlled area degradation enables a study of adhesive bond strengths. These dot patterns may also be applied to force-limiting devices which must depend on the adhesive bonding strength between mating surfaces.
Semiatomistic model for nonductile fracture based on analysis of static and dynamic stress concentrations in uniaxial fiber-matrix composite materials
Plane stress crack propagation of aluminum and titanium alloys at cryogenic temperatures
The specific experimental investigation undertaken was designed to answer these questions on Ti-6Al-4V in the solution treated and aged condition. The defect growth and fracture characteristics were studied in parent (unwelded) and welded sheet material. The results of the study indicate that cryogenic proof testing will screen smaller size defects than proof testing at ambient conditions. However some unusual crack growth behavior during the proof test simulation suggests that some further study be made of stress and time duration effects.
Nondestructive tests, fracture mechanics, and welding techniques for aluminum alloys
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Sonic impedance testing detects voids and unbonded regions as small as 1 inch in diameter by 0.03 inch thick. Measurements are made manually or by automatic scanning and the readout is made by meter or recorder.
Radiographic, penetrant, ultrasonic shear wave and ultrasonic delta inspection methods for critical defect determination
Fracture crack propagation in Inconel at room and cryogenic temperatures for surface defective samples
Surface defect detection by reflected microwave radiation pattern
Structural analysis of circular crack partially embedded in solid of finite thickness
Experimental investigation to determine stability, surface deformation characteristics, and extent of plastic yielding associated with surface cracks in plates subjected to tensile loading
A combined analytical and experimental program was conducted to determine the deformation characteristics of deep surface cracks in Mode I loading. An approximate plane finite element analysis was performed to make a parameter study on the influence of crack depth, crack geometry, and stress level on plastic zones, crack opening displacement, and back surface dimpling in Fe-3Si steel and 2219-T87 aluminum. Surface replication and profiling techniques were used to examine back surface dimple configurations in 2219-T87 aluminum. Interferometry and holography were used to evaluate the potential of various optical techniques to detect small surface dimples on large surface areas.