Francis Sabourin, Jérôme Carbonniere and Michel Brunet
The purpose of this paper is to present a quadrilateral shell element using 16 degrees of freedom (dof) (12 translations and four rotations) which makes a pair with Morley's…
Abstract
Purpose
The purpose of this paper is to present a quadrilateral shell element using 16 degrees of freedom (dof) (12 translations and four rotations) which makes a pair with Morley's triangle at 12 dof. This latter has been updated by Batoz who later proposed an extension to a quadrilateral (“DKQ16”) but only with special interpolation functions for an elastic behaviour of the material. Precisely, it is in order to release from this strong limitation that a completely different formulation is proposed here.
Design/methodology/approach
The development of this new quadrilateral called “DKS16” involves three stages. The first one starts from Morley's triangle updated by Batoz (“DKT12”) to derive a rotation‐free (RF) triangular element (“S3”). The second stage consists in generalising this triangle to a RF quadrilateral (“S4”). During the final leg, the S4 and DKT12 main features are combined to give the quadrilateral “DKS16”.
Findings
Other parameters being equal, the type of finite element chosen for the forming stage simulation has a great influence on further springback result even in software with automatic remeshing. Particularly, it is pointed out that the RF shell elements S3 and S4 as well as the triangle DKT12 are less sensitive to the mesh size than classical shell elements with six dof per node. But, even if some improvements of in‐plane shear have been proposed, stamping codes users are reluctant to use triangles. That is why this paper presents an attempt to extrapolate a quadrilateral (DKS16) from the triangle DKT12 via S3 and S4 elements formulation. Numerous examples showing convergence and accuracy are presented: irregular meshes, large displacement analyses and deep‐drawing simulations.
Practical implications
The triangular “S3” element is already implemented in RADIOSS® software and its implementation – as well as the one of “DKT12” – is in progress in Pam‐Stamp, both as “user elements”. The next step will be the implementation of the quadrilateral “S4” (RF) and, maybe, the element “DKS16” since both are cheaper in terms of computation time and are found interesting for sheet forming.
Originality/value
It seems obvious that curvatures are more exactly captured in RF elements (when nodes slide on die radius) since they are imposed in terms of translations instead of traditional nodal rotations not managed by contact conditions. As the neighbours are involved, a drawback of these RF elements is their complex formulation in case of branching surfaces and/or abrupt variations in material behaviour and/or thickness. This is not the case for elements such as DKT12 or DKS16, good candidates to add to the (long) list of cheap shell elements for large scale computations typical of sheet metal forming.
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Francis Sabourin and Michel Brunet
The aim of this paper is to present an enriched formulation of a rotation‐free (RF) triangular shell element in order to use it for shells of general shapes while, up to now, it…
Abstract
Purpose
The aim of this paper is to present an enriched formulation of a rotation‐free (RF) triangular shell element in order to use it for shells of general shapes while, up to now, it is limited to shells without branching surfaces and progressive variations in terms of material behavior and thickness.
Design/methodology/approach
The formulation keeps the main characteristic of Morley's element: bending effects can be expressed with three “bending angles” only. But, for a RF element, these angles are defined with the rigid body rotations of the element itself and those of its neighbours. This usual formulation of a RF shell element can be extended provided that curvatures‐displacements relation involves the material characteristics of the element itself and of its neighbours and the same goes for thickness.
Findings
Numerous examples with regular and irregular meshes of structures involving branching surfaces point out convergence and accuracy. Large displacement analyses – including crash simulations – show the effectiveness, too. A deep‐drawing of a “U” shape and the following springback prediction highlight the fact that the curvatures are captured more exactly (when nodes slide on die radius) since they are imposed in terms of translations whereas they are traditionally computed with nodal rotations not managed by contact conditions on the tooling.
Practical implications
The “S3” element detailed here is implemented in RADIOSS® software. The general conclusions are that this triangle often gives almost the same result as “DKT18” but is two times less cheaper and it is found interesting for sheet forming simulations.
Originality/value
Specificity of such an element clearly appears while lifting the initial restrictions quoted before.
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Visual stimulation affects the taste of food and beverages. This study aimed to understand how latte art affects coffee consumption by collecting participants' brainwave data and…
Abstract
Purpose
Visual stimulation affects the taste of food and beverages. This study aimed to understand how latte art affects coffee consumption by collecting participants' brainwave data and their taste responses.
Design/methodology/approach
Seventy subjects participated in a two-stage experiment. Electroencephalography (EEG) was employed to measure brainwave activity. With an interval of one week, each stage involved coffee consumption with and without latte art. The responses to the taste of the coffee were also collected for analysis.
Findings
Significant differences were found in the participants' alpha and beta brainwave bands. When drinking coffee with latte art, the participants' alpha bands were significantly lower, whereas the beta bands were higher. These findings were supported by Bayesian statistics. A significant increase was found in the participants' taste of sweetness and acidity with latte art, and Bayesian statistics confirmed the results for sweetness although the evidence on the increase in acidity was anecdotal. No difference was found in the taste of bitterness.
Originality/value
This study highlights the effect of latte art on coffee consumption. The authors analysed the empirical evidence from this two-stage experimental study in the form of the participants' brainwave data and their responses to taste. This study's original contribution is that it explored the crossmodal effects of latte art on consumers' taste of coffee from a neuroscientific perspective. The results of this study can provide empirical evidence on how to effectively use latte art in practical business environments.
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Laure Le Treut, François Poinso, Pauline Grandgeorge, Elisabeth Jouve, Michel Dugnat, Joshua Sparrow and Jokthan Guivarch
Studies of the first year of infant psychomotor development in cases of maternal postpartum depression are lacking. The mother and baby unit (MBU) is a healthcare system available…
Abstract
Studies of the first year of infant psychomotor development in cases of maternal postpartum depression are lacking. The mother and baby unit (MBU) is a healthcare system available to infants and their mothers during the postpartum period in a psychiatric hospital, which provides support and preserves the parent's role in the child's daily care. The aim of the paper is to describe the developmental profile of babies of mothers with severe postpartum depression treated in an MBU through the developmental quotients. Using the Brunet-Lézine scale, we studied six-month-old infants whose mothers were hospitalized. The study population consisted of 15 infants. The mean global developmental quotient score was 96.7. A developmental quotient lower than 80 was not observed for any of the children. We found no global psychomotor developmental delays. Despite this, the posture subscore was the area in which we observed the most difficulties. It is possible that the tonic dialogue between the mother and infant is disrupted by maternal depression.
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Meng-Hsien (Jenny) Lin, Samantha N.N. Cross, William J. Jones and Terry L. Childers
This paper aims to review past papers focused on understanding consumer-related topics in marketing and related interdisciplinary fields to demonstrate the applications of…
Abstract
Purpose
This paper aims to review past papers focused on understanding consumer-related topics in marketing and related interdisciplinary fields to demonstrate the applications of electroencephalogram (EEG) in consumer neuroscience.
Design/methodology/approach
In addition to the review of papers using EEG to study consumer cognitive processes, the authors also discuss relevant decisions and considerations in conducting event-related potential (ERP) studies. Further, a framework proposed by Plassmann et al. (2015) was used to discuss the applications of EEG in marketing research from papers reviewed.
Findings
This paper successfully used Plassmann et al.’s (2015) framework to discuss five applications of neuroscience to marketing research. A review of growing EEG studies in the field of marketing and other interdisciplinary fields reveals the advantages and potential of using EEG in combination with other methods. This calls for more research using such methods.
Research limitations/implications
A technical overview of ERP-related terminology provides researchers with a background for understanding and reviewing ERP studies. A discussion of method-related considerations and decisions provides marketing researchers with an introduction to the method and refers readers to relevant literature.
Practical implications
The marketing industry has been quick to adopt cutting edge technology, including EEG, to understand and predict consumer behavior for the purpose of improving marketing practices. This paper connects the academic and practitioner spheres by presenting past and potential EEG research that can be translatable to the marketing industry.
Originality/value
The authors review past literature on the use of EEG to study consumer-related topics in marketing and interdisciplinary fields, to demonstrate its advantages over-traditional methods in studying consumer-relevant behaviors. To foster increasing use of EEG in consumer neuroscience research, the authors further provide technical and marketing-specific considerations for both academic and market researchers. This paper is one of the first to review past EEG papers and provide methodological background insights for marketing researchers.
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Jéromine Dumon, Yannick Bury, Nicolas Gourdain and Laurent Michel
The development of reusable space launchers requires a comprehensive knowledge of transonic flow effects on the launcher structure, such as buffet. Indeed, the mechanical…
Abstract
Purpose
The development of reusable space launchers requires a comprehensive knowledge of transonic flow effects on the launcher structure, such as buffet. Indeed, the mechanical integrity of the launcher can be compromised by shock wave/boundary layer interactions, that induce lateral forces responsible for plunging and pitching moments.
Design/methodology/approach
This paper aims to report numerical and experimental investigations on the aerodynamic and aeroelastic behavior of a diamond airfoil, designed for microsatellite-dedicated launchers, with a particular interest for the fluid/structure interaction during buffeting. Experimental investigations based on Schlieren visualizations are conducted in a transonic wind tunnel and are then compared with numerical predictions based on unsteady Reynolds averaged Navier–Stokes and large eddy simulation (LES) approaches. The effect of buffeting on the structure is finally studied by solving the equation of the dynamics.
Findings
Buffeting is both experimentally and numerically revealed. Experiments highlight 3D oscillations of the shock wave in the manner of a wind-flapping flag. LES computations identify a lambda-shaped shock wave foot width oscillations, which noticeably impact aerodynamic loads. At last, the experiments highlight the chaotic behavior of the shock wave as it shifts from an oscillatory periodic to an erratic 3D flapping state. Fluid structure computations show that the aerodynamic response of the airfoil tends to damp the structural vibrations and to mitigate the effect of buffeting.
Originality/value
While buffeting has been extensively studied for classical supercritical profiles, this study focuses on diamond airfoils. Moreover, a fluid structure computation has been conducted to point out the effect of buffeting.
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This paper gives a review of the finite element techniques (FE) applied in the area of material processing. The latest trends in metal forming, non‐metal forming, powder…
Abstract
This paper gives a review of the finite element techniques (FE) applied in the area of material processing. The latest trends in metal forming, non‐metal forming, powder metallurgy and composite material processing are briefly discussed. The range of applications of finite elements on these subjects is extremely wide and cannot be presented in a single paper; therefore the aim of the paper is to give FE researchers/users only an encyclopaedic view of the different possibilities that exist today in the various fields mentioned above. An appendix included at the end of the paper presents a bibliography on finite element applications in material processing for 1994‐1996, where 1,370 references are listed. This bibliography is an updating of the paper written by Brannberg and Mackerle which has been published in Engineering Computations, Vol. 11 No. 5, 1994, pp. 413‐55.
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Anna Akhmedova, Neus Vila-Brunet and Marta Mas-Machuca
The sharing economy is the internet-enabled business model that has changed the way people travel, work and interact. Similar to other internet-enabled settings, trust is of…
Abstract
Purpose
The sharing economy is the internet-enabled business model that has changed the way people travel, work and interact. Similar to other internet-enabled settings, trust is of paramount importance for the sharing economy as it leads to continued use and positive word-of-mouth. The main objectives of this research are twofold: (1) to identify the most relevant antecedents of trust in the sharing economy; and (2) to identify which combination of these antecedents allows repurchase intention and positive word-of-mouth to be achieved.
Design/methodology/approach
Through revision of trust theories and complementary frameworks, and an analysis of the sharing economy, the authors develop a model of trust for the sharing economy. The authors propose a model assuming that different types of trust will form a limited number of pathways valid for the creation of positive behavioural intentions. The authors use qualitative comparative analysis to empirically assess the proposed model on a sample of 235 sharing economy users.
Findings
The authors find two configurations that jointly suggest the key role of website quality and usability in generating consumer trust. The authors propose that, on the one hand, platforms might focus on creating value-added services and increasing the reliability of the platform brand. On the other hand, platforms can focus on creating good signalling mechanisms and educate their service providers towards reliable behaviour.
Originality/value
The authors build a conceptual model of trust in the sharing economy setting, that considers the feedback loops among the combination of several dimensions. The authors define specific strategies for platforms in the sharing economy that lead to repurchase intention and positive word-of-mouth.