Studying the Possibility of the Destruction Control of Machine Parts by Applying Directed Sharp Concentrators
Issue:
Volume 5, Issue 4, December 2020
Pages:
39-45
Received:
5 November 2020
Accepted:
4 December 2020
Published:
16 December 2020
Abstract: The problem of preventing fatigue failure is highly relevant in all branches of engineering, especially for such structures, the failure of parts in which can lead to accidental effects. But this problem is becoming incredibly important recently due to the need of intensively increasing of the service life and reliability of machines during operation. As a rule, particular attention is paid to the study of the areas in the details with the sharp change in share and size, in which local zones with stress changes exist, leading to the appearance of cracks and, ultimately, to the destruction of these parts. The most extensive research in this area has been performed on various samples. However, the obtained results do not allow to describe the stress state and the stress concentrators with the help of analytical dependencies, especially in the case of sharp cuts and when superposition of stress concentrations, because they do not take into account the scale factor, state of material, etc. In particular, sharp depressions and small cuts (scratches), which do not reduce the strength of the material according to their concentration coefficients, are of special scientific interest, as well as the development of methods for controlling the destruction process. The usage of numerical methods (in particular, the finite element method) significantly expands the possibilities of analysis of stresses in the concentrators of samples and parts. However despite the results achieved, it is considered that it is still difficult to obtain a satisfactory solution for the stress field in the part’s concentrator, taking into account local design features. The article examines the stress state and fatigue resistance under bending loading of the on specially developed physical models of a crankshaft produced with different technologies, having a sharp decrease in the radii of fillets. Models with applied sharp concentrators of various geometries were tested. The performed studies allow to conclude that research in this direction is promising, since new knowledge about stress concentrators and their effect on the fatigue strength of full-scale parts can open up new reserves for increasing the fatigue strength of full-scale structures.
Abstract: The problem of preventing fatigue failure is highly relevant in all branches of engineering, especially for such structures, the failure of parts in which can lead to accidental effects. But this problem is becoming incredibly important recently due to the need of intensively increasing of the service life and reliability of machines during operati...
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Learning from the National Manufacturing Industrial System
Michele Lo Re,
Eleonora Veglianti,
Fabrizio Parente
Issue:
Volume 5, Issue 4, December 2020
Pages:
46-54
Received:
1 December 2020
Accepted:
9 December 2020
Published:
31 December 2020
Abstract: The recent wave of rising protectionism and re-internationalization of capital poses a significant challenge to national industrial system that structures the network and governance firms. This work aims to analyze the global commercial network of the Italian manufacturing industry under the lenses of the network analysis, describing its peculiarities and the development and internationalization paths of its international branches. The originality of the work is also that improving the ability to analyze and manage information extracted from unstructured data (stemming from notes to the firm financial statements). An adjacency matrix created on BvD-Orbis (Bureau van Dijk Electronic Publishing) flagship company database. It contains information about over 12.000 large Italian companies and belonging to one or more of 17.000 different branches in 2017. In this way it was possible to understand the evolving dynamics of the sales network of the Italian branches. The results confirm that the manufacturing industry represents a significant challenge for the design of industrial policy for the national industrial system, highlighting that the structural changes in global production have aroused renewed interest in the role of this sector in promoting economic development and policy. Following this perspective, we demonstrate the relationship between the network of countries shared by Italian companies and we highlight the fundamental characteristics in the structure of intersectoral connections.
Abstract: The recent wave of rising protectionism and re-internationalization of capital poses a significant challenge to national industrial system that structures the network and governance firms. This work aims to analyze the global commercial network of the Italian manufacturing industry under the lenses of the network analysis, describing its peculiarit...
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