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1 – 10 of 55Benedetto Allotta, Lorenzo Fiorineschi, Susanna Papini, Luca Pugi, Federico Rotini and Andrea Rindi
This study aims to carry out an investigation of design approaches that should be used for the design of unconventional, innovative transmission system for construction yards to…
Abstract
Purpose
This study aims to carry out an investigation of design approaches that should be used for the design of unconventional, innovative transmission system for construction yards to privilege a smooth behaviour efficiency, and the use of innovative production techniques. Results are quite surprising, as with a proper method it is possible to demonstrate that a cycloidal drive with Wolfrom topology should be an interesting solution for the proposed application.
Design/methodology/approach
With a functional approach, also considering materials and specifications related to the investigated application, it is possible to demonstrate that possible optimal solutions should be quite different respect to the ones that can be suggested with a conventional approach. In particular for proposed applications constraints related to encumbrances, the choice of new material has led to the innovative unconventional choice of a Wolfrom cycloidal speed reducer.
Findings
Provided solution is innovative respect current state of the art for machine currently used in construction yards: in terms of adopted transmission layout; in terms of chosen materials, resulting in an innovative solution.
Research limitations/implications
Current research has strong implications on the adoption of polimeric materials for the construction of reliable transmission for harsh industrial environment as the proposed case study (concrete mixer for construction yard).
Originality/value
Proposed transmission system is absolutely original and innovative respect current state of art also considering proposed materials and consequently production methods. This is an example of transmission designed to be built with polymeric materials by optimizing chosen topology respect to chosen material.
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Jorge Manuel Mercado-Colmenero, M. Dolores La Rubia, Elena Mata-García, Moisés Rodriguez-Santiago and Cristina Martin-Doñate
Because of the anisotropy of the process and the variability in the quality of printed parts, finite element analysis is not directly applicable to recycled materials manufactured…
Abstract
Purpose
Because of the anisotropy of the process and the variability in the quality of printed parts, finite element analysis is not directly applicable to recycled materials manufactured using fused filament fabrication. The purpose of this study is to investigate the numerical-experimental mechanical behavior modeling of the recycled polymer, that is, recyclable polyethylene terephthalate (rPET), manufactured by a deposition FFF process under compressive stresses for new sustainable designs.
Design/methodology/approach
In all, 42 test specimens were manufactured and analyzed according to the ASTM D695-15 standards. Eight numerical analyzes were performed on a real design manufactured with rPET using Young's compression modulus from the experimental tests. Finally, eight additional experimental tests under uniaxial compression loads were performed on the real sustainable design for validating its mechanical behavior versus computational numerical tests.
Findings
As a result of the experimental tests, rPET behaves linearly until it reaches the elastic limit, along each manufacturing axis. The results of this study confirmed the design's structural safety by the load scenario and operating boundary conditions. Experimental and numerical results show a difference of 0.001–0.024 mm, allowing for the rPET to be configured as isotropic in numerical simulation software without having to modify its material modeling equations.
Practical implications
The results obtained are of great help to industry, designers and researchers because they validate the use of recycled rPET for the ecological production of real-sustainable products using MEX technology under compressive stress and its configuration for numerical simulations. Major design companies are now using recycled plastic materials in their high-end designs.
Originality/value
Validation results have been presented on test specimens and real items, comparing experimental material configuration values with numerical results. Specifically, to the best of the authors’ knowledge, no industrial or scientific work has been conducted with rPET subjected to uniaxial compression loads for characterizing experimentally and numerically the material using these results for validating a real case of a sustainable industrial product.
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Marcus Achenbach and Guido Morgenthal
The purpose of this paper is to develop a method suitable for the design of reinforced concrete columns subjected to a standard fire.
Abstract
Purpose
The purpose of this paper is to develop a method suitable for the design of reinforced concrete columns subjected to a standard fire.
Design/methodology/approach
The Zone Method – a ’simplified calculation method” included in Eurocode 2 – has been developed by Hertz as a manual calculation scheme for the check of fire resistance of concrete sections. The basic idea is to disregard the thermal strains and to calculate the resistance of a cross-section by reducing the concrete cross-section by a “damaged zone”. It is assumed that all fibers can reach their ultimate, temperature dependent strength. Therefore, it is a plastic concept; the information on the state of strain is lost. The calculation of curvatures and deflections is thus only possible by making further assumptions. Extensions of the zone method toward a general calculation method, suitable for the implementation in commercial design software and using the temperature dependent stress–strain curves of the Advanced Calculation Method, have been developed in Germany. The extension by Cyllok and Achenbach is presented in detail. The necessary assumptions of the Zone Method are reviewed, and an improved proposal for the consideration of the reinforcement in this extended Zone Method is presented.
Findings
The principles and assumptions of the Zone Method proposed by Hertz can be validated.
Originality/value
An extension of the Zone Method suitable for the implementation in design software is proposed.
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Michael Brown argues that what unites the human and social sciences is their evolving character, made explicit in the concepts of “reflexivity,” “course of activity,” and…
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Michael Brown argues that what unites the human and social sciences is their evolving character, made explicit in the concepts of “reflexivity,” “course of activity,” and “theorizing.” Once the social sciences are taken as a whole, the notion of “sociality” will allow to grasp society as ever changing, as a becoming. I shall examine the notion of sociality in the literary criticism of Lukács, Goldmann, and Adorno, three authors who consider the essay as the adequate open form of critique in times of rapid social change. Originally adopted by the young Lukács, the essay tended to be abandoned by him when elaborating the concept of critical or socialist realism as a repository of timeless cultural values. In his studies in the European realist or the soviet novel, for example, on Balzac, Stendhal, Thomas Mann, or Solzhenitsyn, the dialectical concept of social totality becomes a sum of orientations, presenting the individual writer with the moral task to choose “progress” and discard “negativity.” The social is thus narrowed to individual choice. Different from Lukács, Goldmann's literary theory defines cultural production as a matter of the social group, the transindividual subject. Goldmann was deeply marked by Lukács's early writings from which he gained notably the notion of tragedy and the concept of maximum possible consciousness—the world vision of a social group which structures the work of a writer. Cultural creation is resistance to capitalist society, as evident in the literature of absence, Malraux's novels, and the nouveau roman. In the writings of Adorno the social is lodged within the avant-garde, provided that one takes its means and procedures literally, e.g., the writings of Kafka. By formal innovation—among others the adoption of the essay, the small form, the fragment—art exercises criticism of the ongoing rationalization process and preserves the possibility of change (p. 319).
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