scholarly journals Review of Finite Element Vehicle Interior Acoustic Simulations Including Porous Materials

Author(s):  
János Csaba Kun ◽  
Daniel Feszty

Recent trends in vehicle engineering require manufacturers to develop products with highly refined noise, vibration and harshness levels. The use of trim elements, which can be described as Poroelastic materials (PEM), are key to achieve quiet interiors. Finite Element Methods (FEM) provide established solutions to simple acoustic problems. However, the inclusion of poroelastic materials, especially at higher frequencies, proves to be a difficult issue to overcome. The goal of this paper was to summarize the state-of-the-art solutions to acoustic challenges involving FEM-PEM simulation methods. This involves investigation of measurement and simulation campaigns both on industrial and fundamental academic research levels.

2019 ◽  
Vol 12 (4) ◽  
pp. 347-370
Author(s):  
Marcell Ferenc Treszkai ◽  
Dániel Feszty

In the vehicle industry, the noise, vibration and harshness (NVH) characteristics of a car are becoming more and more important. In order to control these, it is necessary to know the sources and contributors to the interior noise level. This paper provide an overview of the state-of-the-art on predicting the NVH characteristics of fully trimmed vehicles in the mid-frequency gap between 400 Hz to 1 kHz. It is shown that for this frequency range, typically a hybrid FE-SEA method is used. This method provides a mixture of the advantages of the deterministic and statistical approaches. The first part of the paper introduces the method, followed by an overview of the different fields of usage in the vehicle industry. At the end of the paper, gaps in the knowledge are identified.


2008 ◽  
Vol 600-603 ◽  
pp. 895-900 ◽  
Author(s):  
Anant K. Agarwal ◽  
Albert A. Burk ◽  
Robert Callanan ◽  
Craig Capell ◽  
Mrinal K. Das ◽  
...  

In this paper, we review the state of the art of SiC switches and the technical issues which remain. Specifically, we will review the progress and remaining challenges associated with SiC power MOSFETs and BJTs. The most difficult issue when fabricating MOSFETs has been an excessive variation in threshold voltage from batch to batch. This difficulty arises due to the fact that the threshold voltage is determined by the difference between two large numbers, namely, a large fixed oxide charge and a large negative charge in the interface traps. There may also be some significant charge captured in the bulk traps in SiC and SiO2. The effect of recombination-induced stacking faults (SFs) on majority carrier mobility has been confirmed with 10 kV Merged PN Schottky (MPS) diodes and MOSFETs. The same SFs have been found to be responsible for degradation of BJTs.


Author(s):  
Jorge Ambrósio ◽  
Marta Carvalho ◽  
João Milho ◽  
Susana Escalante ◽  
Roberto Martín

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Patrizia Garengo ◽  
Alberto Sardi

PurposeSince the 1980s, performance measurement and management (PMM) has been described as an essential element of new public management (NPM) reforms. The purpose of this paper is to provide an overview of the current state of the art and future research opportunities for PMM in public sector management.Design/methodology/approachThe paper carried out a bibliometric literature review using two main techniques named (1) performance analysis and (2) science mapping techniques. It investigated the academic research area describing the main publications' trend, the conceptual structure and its evolution from 1996 to 2019.FindingsThe results highlighted the growing relevance of PMM research in public organisations and confirmed a great interest of the business, management and accounting literature on PMM in public sector management. Furthermore, the results also described a conceptual structure of the public PMM literature analysed and its evolution being too generic to answer public organisations' needs. The results identified five main research gaps and research opportunities.Originality/valueAlthough the adoption of rigorous bibliometric techniques was recognised as being useful for assessing the academic research study, the paper describes the business, management and accounting literature contributing to new theoretical and practical future opportunities.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Gianluigi Guido ◽  
Marco Pichierri ◽  
Cristian Rizzo ◽  
Verdiana Chieffi ◽  
George Moschis

Purpose The purpose of this study is to review scholarly research on elderly consumers’ information processing and suggest implications for services marketing. Design/methodology/approach The review encompasses a five-decade period (1970–2018) of academic research and presents relevant literature in four main areas related to information processing: sensation, attention, interpretation and memory. Findings The study illustrates how each of the aforementioned phases of the information processing activity may affect how elderly individuals buy and consume products and services, emphasizing the need for a better comprehension of the elderly to develop effectual marketing strategies. Originality/value The study provides readers with detailed state-of-the-art knowledge about older consumers’ information processing, offering a comprehensive review of academic research that companies can use to improve the effectiveness of their marketing efforts that target the elderly market.


Author(s):  
EVA DESDENTADO DAROCA

La interdicción de la arbitrariedad y las obligaciones de motivar y justificar las decisiones se han erigido en pilares claves del control judicial de la actividad administrativa. Sin embargo, siguen subsistiendo problemas, tanto conceptuales como de aplicación, que presentan un indudable interés: se discute la naturaleza formal o sustantiva de la motivación; las relaciones entre motivación y justificación siguen siendo complejas y controvertidas; no existe acuerdo sobre la obligación o no de motivar resoluciones administrativas que aplican conceptos jurídicos indeterminados; el principio de la autorrestricción judicial en el control de la motivación cede en algunos sectores mientras se mantiene de forma más que discutible en otros; y las últimas líneas jurisprudenciales evidencian que la determinación del alcance legítimo del control judicial sigue siendo conflictiva. El presente trabajo lleva a cabo una valoración crítica de las últimas orientaciones tanto en la doctrina científica como jurisprudencial, al mismo tiempo que ofrece propuestas conceptuales e interpretativas para contribuir a una adecuada evolución de estos aspectos oscuros del control judicial de la Administración. rbitrariotasunaren debekua eta erabakiak arrazoitzeko eta justifikatzeko betebeharrak oinarrizko zutabe bihurtu dira administrazio-jardueraren kontrol judizialean. Hala ere, oraindik arazo batzuk diraute, direla kontzeptualak, direla aplikaziokoak, eta interes ukaezina dute horiek guztiek: arrazoiketaren izatasun formala edo substantiboa eztabaidatzen da; arrazoiketaren eta justifikazioaren arteko harremanak konplexuak eta eztabaidagarriak dira oraindik; ez dago adostasunik kontzeptu juridiko zehaztugabeak aplikatzen dituzten administrazio-ebazpenak arrazoitu edo ez arrazoitu beharraz; arrazoiketaren kontroleko automurrizketa judizialak atzera egin du sektore batzuetan, eta beste batzuetan, aldiz, modu aski eztabaidagarrian mantendu da, eta azkeneko lerro jurisprudentzialek erakusten dute kontrol judizialaren irismen zilegia gatazkatsua dela oraindik. Honako lan honek balioespen kritiko bat egiten du doktrina zientifikoan zein jurisdikzionalean dauden azken jarraibideetan, eta era berean proposamen kontzeptual eta interpretatibo batzuk eskaintzen ditu, Administrazioaren kontrol judizialaren alderdi ilun horien bilakaera egokiari laguntzeko. The prohibition of arbitrariness, the duty to give reasons and the duty to justify decisions have become principles of main relevance in the judicial control of administrative discretion. However, there still remain important and interesting theoretical and practical problems: the formal or substantive nature of motivation is controversial; the relationship between motivation and justification is difficult and unclear; there is no agreement over the duty to motivate decisions that apply opentexture concepts; our tribunals leave the doctrine of self-restriction in some cases at the same time that they strongly maintained it in others without a clear justification; and the last judicial resolutions that determine the scope of the duty to give reasons show that this is still a difficult issue. This article approaches a critical analysis of the recent trends in these fields with the purpose to offer theoretical and interpretative proposals that should contribute to an adequate evolution of these problematic aspects of the judicial control of the Administration.


2011 ◽  
Author(s):  
David Fornaro

Finite Element Analysis (FEA) is mature technology that has been in use for several decades as a tool to optimize structures for a wide variety of applications. Its application to composite structures is not new, however the technology for modeling and analyzing the behavior of composite structures continues to evolve on several fronts. This paper provides a review of the current state-of-the-art with regard to composites FEA, with a particular emphasis on applications to yacht structures. Topics covered are divided into three categories: Pre-processing; Postprocessing; and Non-linear Solutions. Pre-processing topics include meshing, ply properties, laminate definitions, element orientations, global ply tracking and load case development. Post-processing topics include principal stresses, failure indices and strength ratios. Nonlinear solution topics include progressive ply failure. Examples are included to highlight the application of advanced finite element analysis methodologies to the optimization of composite yacht structures.


2012 ◽  
Vol 11 (4) ◽  
pp. 1043-1080 ◽  
Author(s):  
Remi Abgrall

AbstractWe describe and review non oscillatory residual distribution schemes that are rather natural extension of high order finite volume schemes when a special emphasis is put on the structure of the computational stencil. We provide their connections with standard stabilized finite element and discontinuous Galerkin schemes, show that their are really non oscillatory. We also discuss the extension to these methods to parabolic problems. We also draw some research perspectives.


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