1,987 research outputs found

    Probabilistic Simulation of Stress Concentration in Composite Laminates

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    A computational methodology is described to probabilistically simulate the stress concentration factors (SCF's) in composite laminates. This new approach consists of coupling probabilistic composite mechanics with probabilistic finite element structural analysis. The composite mechanics is used to probabilistically describe all the uncertainties inherent in composite material properties, whereas the finite element is used to probabilistically describe the uncertainties associated with methods to experimentally evaluate SCF's, such as loads, geometry, and supports. The effectiveness of the methodology is demonstrated by using is to simulate the SCF's in three different composite laminates. Simulated results match experimental data for probability density and for cumulative distribution functions. The sensitivity factors indicate that the SCF's are influenced by local stiffness variables, by load eccentricities, and by initial stress fields

    Atomization simulations using an Eulerian-VOF-Lagrangian method

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    This paper summarizes the technical development and validation of a multiphase computational fluid dynamics (CFD) numerical method using the volume-of-fluid (VOF) model and a Lagrangian tracking model which can be employed to analyze general multiphase flow problems with free surface mechanism. The gas-liquid interface mass, momentum and energy conservations are modeled by continuum surface mechanisms. A new solution method is developed such that the present VOF model can be applied for all-speed flow regimes. The objectives of the present study are to develop and verify the fractional volume-of-fluid cell partitioning approach into a predictor-corrector algorithm and to demonstrate the effectiveness of the present innovative approach by simulating benchmark problems including the coaxial jet atomization

    The fcc-bcc crystallographic orientation relationship in AlxCoCrFeNi high-entropy alloys

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    This paper concentrates on the crystallographic-orientation relationship between the various phases in the Al-Co-Cr-Fe-Ni high-entropy alloys. Two types of orientation relationships of bcc phases (some with ordered B2 structures) and fcc matrix were observed in Al0.5CoCrFeNi and Al0.7CoCrFeNi alloys at room temperature: (1 -1 0)(bcc)//(200)(fcc), [CM](bcc)//[001](fcc), (b) (1 -1 1)B2//(2 - 2 0)(fcc), [011]B2//[11 root 2](fcc). (C) 2016 Elsevier B.V. All rights reserved.</p

    An interactive workshop plus locally adapted guidelines can improve General Practitioners asthma management and knowledge: A cluster randomised trial in the Australian setting

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    Background A cluster randomised trial was conducted to determine the effectiveness of locally adapted practice guidelines and education about paediatric asthma management, delivered to general practitioners (GPs) in small group interactive workshops. Methods Twenty-nine practices were randomly allocated to one of three study arms. Australian asthma management guidelines were adapted to accommodate characteristics of the local area. GPs in the intervention arm (Group 1, n = 18 GPs) participated in a small group based education program and were provided with the adapted guidelines. One control arm (Group 2, n = 18 GPs) received only the adapted guidelines, while the other control arm (Group 3, n = 15 GPs) received an unrelated education intervention. GPs' knowledge, attitudes and management of paediatric asthma was assessed. Results Post intervention, intervention arm GPs were no more likely to provide a written asthma action plan, but were better able to assess the severity of asthma attack (Group 1vs Group 2 p = 0.05 and Group 1 vs Group 3 p = 0.01), better able to identify patients at high risk of severe attack (Group 1vs Group 3 p = 0.06), and tended to score higher on the asthma knowledge questionnaire (Group 1 vs Group 2 p = 0.06 and Group 1 vs Group 3 p = 0.2). Most intervention arm GPs felt more confident than control GPs to manage acute asthma attack and ongoing management of infrequent episodic asthma. Conclusion Using interactive small group workshops to disseminate locally adapted guidelines was associated with improvement in GP's knowledge and confidence to manage asthma, but did not change GP's self-reported provision of written action plans.Siaw-Teng Liaw, Nabil D Sulaiman, Christopher A Barton, Patty Chondros, Claire A Harris, Susan Sawyer and Shyamali C Dharmag
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