1,721,035 research outputs found
FEM and experimental analysis of a total knee prosthesis
No full textIn this study, a comparison between two different approaches used to study a total knee prosthesis is presented. In particular, the contact area of the components of knee prosthesis has been evaluated using both a numerical and an experimental approach. The numerical analysis has been performed by FEM Models, whereas the experimental study has been conducted using an ultrasonic-based method. To setup the FEM simulations, CAD Models of the components of the prosthesis have been reconstructed using a classic reverse engineering approach. Obtained results has allowed evaluating the contact area of the components of the prosthesis and demonstrated a very good level of correlation between numerical and experimental data
Fractional Calculus as a New Perspective in the Viscoelastic Behaviour of the Intervertebral Disc
No full textThe spinal column is the load-bearing structure of the human being along with its components, which together build a strong, resistant, and stable structure, but there are a few different pathologies from which it can suffer, such as herniated discs. The intervertebral disc acts as a shock absorber and ensures the spine’s great capacity to support high loads and different states of stress, thanks to its viscoelastic properties. Some studies have attempted to describe the viscoelastic behaviour of the intervertebral disc using classical rheological models, such as the Kelvin-Voigt, or multi-parameter models. Even if these models partially describe the viscoelastic response of disc, all viscoelastic characteristics are not fully captured. This article aims to present the current studies on the biomechanics of intervertebral disc and to introduce a new approach using the powerful mathematical tool of fractional calculus. With fractional rheological models, it could be possible to formulate a fractional law that can fully describe the viscoelastic behaviour of the intervertebral disc. This new approach could lead to a breakthrough in the study of herniated pathologies by understanding how the intervertebral disc is damaged and identifying strategies to deal with these pathological problems
Improving the Downwind Sail Design Process by Means of a Novel FSI Approach
Full text linkThe process of designing a sail can be a challenging task because of the difficulties in predicting the real aerodynamic performance. This is especially true in the case of downwind sails, where the evaluation of the real shapes and aerodynamic forces can be very complex because of turbulent and detached flows and the high-deformable behavior of structures. Of course, numerical methods are very useful and reliable tools to investigate sail performances, and their use, also as a result of the exponential growth of computational resources at a very low cost, is spreading more and more, even in not highly competitive fields. This paper presents a new methodology to support sail designers in evaluating and optimizing downwind sail performance and manufacturing. A new weakly coupled fluid–structure interaction (FSI) procedure has been developed to study downwind sails. The proposed method is parametric and automated and allows for investigating multiple kinds of sails under different sailing conditions. The study of a gennaker of a small sailing yacht is presented as a case study. Based on the numerical results obtained, an analytical formulation for calculating the sail corner loads has been also proposed. The novel proposed methodology could represent a promising approach to allow for the widespread and effective use of numerical methods in the design and manufacturing of yacht sails
Advances on mechanics, design engineering and manufacturing
No full textThe theme of the present editorial is dedicated to the“Advances on Mechanics, Design Engineering and Manufac-turing” that emerge in different engineering and architecturalfields.The theme has been chosen as leitmotiv of a series ofevents that have been organized by three societies operatingin Italy, Spain and France, respectively: ADM (Associ-azione nazionale Disegno e Metodi dell’ingegneria indus-triale), INGEGRAF (Asociación Española de IngenieríaGráfica and AIP-PRIMECA (Ateliers Inter-établissementsde Productique—Pôles de Resources Informatiques pour laMECAnique). Since 2014, a series of JCM conferences havebeen organized. JCM is the acronym of “Joint Conference onMechanics, Design Engineering and Advanced Manufactur-ing”
New algorithms to evaluate the real shape of a hull
No full textIn this study, a new method to compare rebuilt surfaces of hulls of sailing yachts is presented. In particular, the considered rebuilt surfaces are created through classic reverse engineering approaches. The new method has been developed by means of Grasshopper, a free generative algorithms editor that can be used as plugin of Rhinoceros, one of the most widespread free-form modelling software. In particular, two different algorithms have been developed: the first one allows controlling the quality of the rebuilt surfaces, the second one, instead, allows to measure the deviations between the original CAD Model and the rebuilt surface of the hull. A case study related to the hull of a small sailing yacht is also presented. The obtained results have demonstrated the efficiency of the new proposed low-cost method
A Comparative Analysis of Meta-heuristic Algorithms for Finite Element Optimization
No full textIn the field of structural engineering, the optimization process is crucial for ensuring both the efficiency and safety of designed structures. The persistent search for solutions that maximize structural performance while minimizing costs presents a fascinating and complex challenge. In this context, this paper aims to analyze and compare three different Nature-inspired optimization algorithms that are derived from theory of biological evolution, swarm intelligence, and chemical and physical processes. Specifically, the study aims to provide a comprehensive overview of the performance and characteristics of Genetic Algorithms, the Firefly Algorithm, and the Group Search Optimizer Algorithm in the context of struc-tural optimization within the ANSYS APDL environment. The results obtained from each meta-heuristic algorithm will be discussed and compared in terms of their convergence, efficiency, and capability to find optimal and/or approximate solutions
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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