28 research outputs found

    Direct Diode Lasers for Industrial Laser Cutting: A Performance Comparison with Conventional Fiber and CO2 Technologies

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    AbstractThe direct use of diode lasers for cutting sheet metal has high potential to decrease operational costs, but, currently, implementation in industrial environments is constrained by beam quality. In this paper the performance of a novel direct diode laser (DDL) with increased beam quality is documented for both fusion and flame cutting and compared to conventional CO2 and fiber laser sources. Experimental tests were carried out for steel and aluminium based on a Design of Experiments approach. Furthermore, an analytical model, focusing on the absorption of lasers in metals, is described here, which predicts and clarifies performance variation. Although the observed laser beam quality is still lower than the other studied technologies, industrially relevant cutting speeds, with acceptable surface quality, are achievable with DDL, as validated by our result

    Contact modelling of large radius air bending with geometrically exact contact algorithm

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    Usage of high-strength steels in conventional air bending is restricted due to limited bendability of these metals. Large-radius punches provide a typical approach for decreasing deformations during the bending process. However, as deflection progresses the loading scheme changes gradually. Therefore, modelling of the contact interaction is essential for an accurate description of the loading scheme. In the current contribution, the authors implemented a plane frictional contact element based on the penalty method. The geometrically exact contact algorithm is used for the penetration determination. The implementation is done using the OOFEM – open source finite element solver. In order to verify the simulation results, experiments have been conducted on a bending press brake for 4 mm Weldox 1300 with a punch radius of 30 mm and a die opening of 80 mm. The maximum error for the springback calculation is 0.87° for the bending angle of 144°. The contact interaction is a crucial part of large radius bending simulation and the implementation leads to a reliable solution for the springback angle

    Selected Contemporary Challenges of Ageing Policy

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    Among the scholars trying to grasp the nuances and trends of social policy, there are diverse perspectives, resulting not only from the extensive knowledge of the authors on the systematic approach to the issue of supporting older people but also from the grounds of the represented social gerontology schools. In the texts of Volume VII interesting are both distinct and coherent elements presenting the role of local, regional and global policies in the prism of the countries from which the authors originate: the Czech Republic, Slovenia, Lithuania, Latvia, Poland, Slovakia, Italy, Turkey, and the United States. The chapters show a wealth of methodological approaches to the perception of social policy and its tools. In the texts there are issues related to the idea of active ageing, discrimination against older people in the workplace, comparability of solutions friendly to employment of older adults in the Czech Republic, Poland, and Slovakia as well as focused on the importance of educational forms (universities of the third age, senior clubs, folk high schools, and other non-formal solutions) determining an active life in old age. This monograph also attempted to answer the question regarding how to transfer the idea of intergenerational learning into the realm of practice. This issue complements the chapter on the implementation of intergenerational programs in institutions providing long-term care support. The book also outlines a public policy on ageing in the perspective of the changes over the last few decades (Slovenia) and the case demonstrating solutions to accelerate self-reliance as a key to active ageing (Turkey)

    TRIZ for systems architecting

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    TRIZ has gained interest over the past decades, as among others expressed by this conference. It is widely used and acknowledged for dealing with technical issues on component level. However, decisions on system level have a much greater impact than those on component level. Thus it is worthwhile to investigate applying TRIZ early in the design process. The article explores the benefits of and possibilities for applying TRIZ in the architecting phase. For this, system architecting is treated in short. An architecting approach presented earlier will be treated and elaborated upon. This approach connects the customer’s key drivers with functions to be performed. This approach provides leads for integrating TRIZ in the system architecting phase. These will be discussed in detail as the main subject of the paper. Examples, conclusions and ideas for future work complete the paper

    SEABIRD: Scalable search for systematic biologically inspired design

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    As more and more people are increasingly turning to nature for design inspiration, tools and methodologies are developed to support the systematic bioideation process. State-of-the-art approaches struggle with expanding their knowledge bases because of interactive work required by humans per biological strategy. As an answer to this persistent challenge, a scalable search for systematic biologically inspired design (SEABIRD) system is proposed. This system leverages experience from the product aspects in design by analogy tool that identifies candidate products for between-domain design by analogy. SEABIRD is based on two conceptual representations, product and organism aspects, extracted from, respectively, a patent and a biological database, that enable leveraging the ever growing body of natural-language biological texts in the systematic bioinspired design process by eliminating interactive work by humans during corpus expansion. SEABIRD's search is illustrated and validated with three well-known biologically inspired design cases
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