305 research outputs found

    Contact stress analysis of spiral bevel gears using nonlinear finite element static analysis

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    A procedure is presented for performing three-dimensional stress analysis of spiral bevel gears in mesh using the finite element method. The procedure involves generating a finite element model by solving equations that identify tooth surface coordinates. Coordinate transformations are used to orientate the gear and pinion for gear meshing. Contact boundary conditions are simulated with gap elements. A solution technique for correct orientation of the gap elements is given. Example models and results are presented

    Semantic web-based document: editing and browsing in AktiveDoc

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    This paper presents a tool for supporting sharing and reuse of knowledge in document creation (writing) and use (reading). Semantic Web technologies are used to support the production of ontology based annotations while the document is written. Free text annotations (comments) can be added to integrate the knowledge in the document. In addition the tool uses external services (e.g. a Semantic Web harvester) to propose relevant content to writing user, enabling easy knowledge reuse. Similar facilities are provided for readers when their task does not coincide with the author’s one. The tool is specifically designed for Knowledge Management in organisations. In this paper we present and discuss how Semantic Web technologies are designed and integrated in the system

    Low-noise, high-strength, spiral-bevel gears for helicopter transmissions

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    Improvements in spiral-bevel gear design were investigated to support the Army/NASA Advanced Rotorcraft Transmission program. Program objectives were to reduce weight by 25 percent, reduce noise by 10 dB, and increase life to 5000 hr mean-time-between-removal. To help meet these goals, advanced-design spiral-bevel gears were tested in an OH-58D helicopter transmission using the NASA 500-hp Helicopter Transmission Test Stand. Three different gear designs tested included: (1) the current design of the OH-58D transmission except gear material X-53 instead of AISI 9310; (2) a higher-strength design the same as the current but with a full fillet radius to reduce gear tooth bending stress (and thus, weight); and (3) a lower-noise design the same as the high-strength but with modified tooth geometry to reduce transmission error and noise. Noise, vibration, and tooth strain tests were performed and significant gear stress and noise reductions were achieved

    Contact Stress Analysis of Spiral Bevel Gears Using Finite Element Analysis

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    A procedure is presented for performing three-dimensional stress analysis of spiral bevel gears in mesh using the finite element method. The procedure involves generating a finite element model by solving equations that identify tooth surface coordinates. Coordinate transformations are used to orientate the gear and pinion for gear meshing. Contact boundary conditions are simulated with gap elements. A solution technique for correct orientation of the gap elements is given. Example models and results are presented

    Improvements in Spiral-Bevel Gears to Reduce Noise and Increase Strength

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    Advanced-design spiral-bevel gears were tested in an OH-58D helicopter transmission using the NASA 500 hp Helicopter Transmission Test Stand. Four different gear designs were tested. The four designs tested were the current design of the OH-58D transmission, a higher-strength design the same as the current but with an increased fillet radius to reduce gear tooth bending stress, and two versions of a lower-noise design the same as the high-strength but with modified tooth geometry to reduce transmission error and noise. Noise, vibration, and tooth strain tests were performed and significant gear stress and noise reductions were achieved

    Using a Semantic Wiki for Documentation Management in Very Small Projects

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    International audienceThe emerging ISO/IEC 29110 standard Lifecycle profiles for Very Small Entities is targeted at very small entity (VSE) having up to 25 people, to assist them unlock the potential benefits of using software engineering standards. VSEs may use semantic web technologies to improve documentation management infrastructure and processes. We proposed to use a semantic wiki for documentation management based on an identification scheme inspired from an IFLA proposition called Functional Requirements for Bibliographic Records. The document identification scheme allows documents to be managed by the internal resource management of the semantic wiki, hence benefiting from a straightforward but powerful version control. With few inputs of semantic annotations by VSE employees - through usable semantic forms and templates, the semantic wiki acts as a library catalog, and users can find, identify, select, obtain, and navigate resources
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