A simple, ultrasonic method for non-destructively testing commercial optical grinding tools is demonstrated, with results compared to a material database collected for diamond composite tool materials. The ultrasonic ...
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A harmonic balance technique for the analysis of unsteady flows about helicopter rotors in forward flight and hover is presented in this paper. The aerodynamics of forward flight are highly nonlinear, with transonic f...
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The non-uniform spatial arrangement of fibers in composite materials leads to an irregular stress distribution in the microstructure allowing localized microscopic damage mechanisms to occur more easily. In order to a...
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Nanocrystalline iron-chromium alloys may provide considerable corrosion resistance, even at low chromium contents. However, processing of such alloys could be a challenge. This paper describes successful synthesis of ...
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ISBN:
(纸本)9780873397162
Nanocrystalline iron-chromium alloys may provide considerable corrosion resistance, even at low chromium contents. However, processing of such alloys could be a challenge. This paper describes successful synthesis of nanocrystalline Fe-Cr alloys by ball-milling route. In the absence of suitable hot compaction facility, the alloy powder could be successfully compacted close to the desired density, by employing a step of prior annealing of the powder followed by compaction at a relatively low temperature. Grain growth behaviour of Fe-Cr nanocrystalline alloys was investigated at 500, 600 and 700C At 500C, no appreciable grain growth was observed, after the initial period. However, a sudden and rapid grain growth was observed after 90 minutes at 600C, and after 30 minutes at 700C The paper also describes the success in the processing of the nanocrystalline iron-chromium alloys.
This paper presents a detailed two dimensional finiteelement study to examine the effect of introducing a crack either progressively or instantaneously into a residual stress field. A progressive crack is defined as a...
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ISBN:
(纸本)9780791848296
This paper presents a detailed two dimensional finiteelement study to examine the effect of introducing a crack either progressively or instantaneously into a residual stress field. A progressive crack is defined as a crack which is introduced in fixed increments of crack extension until the desired crack length is achieved. An instantaneous crack is one in which a crack of the required length is introduced instantaneously into the finite-element mesh. Inspection is made of the crack tip fields and the crack opening displacements. A modified definition of the J-integral, which accounts for the initial plastic strain due to residual stress, is assessed, in order to examine its ability to characterize the intensity of the near crack tip fields. The implications of the results on fracture assessment of structural components are discussed.
Manatees, listed as endangered species, are marine mammals that are inhabitants of the Florida coastline as well as some of the natural springs The coexistence of the humans and the manatees in the Florida waterways h...
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ISBN:
(纸本)9781605604152
Manatees, listed as endangered species, are marine mammals that are inhabitants of the Florida coastline as well as some of the natural springs The coexistence of the humans and the manatees in the Florida waterways has contributed to the depletion of the manatee population: collisions between watercraft and the manatees are responsible for 25% of all the manatee deaths In an effort to reduce the speed limits in the manatee populated waterways, some studies have been done earlier at the University of Florida (UF) to characterize the manatee rib bone fracture behavior and its impact load carrying capacity Initial estimates and the parallels between other animal studies indicate that the manatee skin acts as an energy absorption element during an impact The purpose of the present study is to characterize the manatee skin in order to understand its response to compressive loading A Visual Image Correlation (VIC) technique is used for the full-field basis measurement of the deformations and the strains VIC results indicate the necessity to model the manatee skin as a layered solid material or functionally graded material The nature of the stress-strain curve indicates the necessity to model the skin via a hyper-elastic idealization.
Microstructure evolution during friction stir processing (FSP) of Ti-5111 (Ti-5Al-lSn-lZr-lV-.8Mo) performed both above and below the beta-transus temperature was investigated. Plate samples for FSP were fully instrum...
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