Numerical Analysis of Acoustic Barriers with a Diffusive Surface Using a 2.5D Boundary Element Model

2015 ◽  
Vol 23 (03) ◽  
pp. 1550009 ◽  
Author(s):  
C. Prieto Gajardo ◽  
L. Godinho ◽  
P. Amado-Mendes ◽  
J. M. Barrigon Morillas
Keyword(s):  
Numerical Model ◽  
Element Model ◽  
The Body ◽  
Noise Mitigation ◽  
Noise Barriers ◽  
Accurate Analysis ◽  
The Road ◽  
Body Of Knowledge ◽  
Surface Profiles ◽  
Computational Analyses

Acoustic barriers are a well-known environmental noise mitigation solution, which is widely used nowadays. In this work, it is expected to contribute to the body of knowledge regarding the physical and technical behavior of those barriers by developing and implementing a set of models that allow an accurate analysis of noise barriers with new configuration types. A 2.5D boundary-only numerical model is developed and implemented, and computational analyses are performed in order to compare different surface profiles of the acoustic barriers. The particular case in which two acoustic barriers are used, one at each side of the road, is addressed.

A FEA Simulation Model for Thin-Walled C-Section Composite Beam Assembling With R-Angle Deviation

2014 ◽  
Author(s):  
Hua Wang ◽  
Suo Si
Keyword(s):  
Numerical Model ◽  
Composite Beam ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Element Model ◽  
Load Level ◽  
Compression Tests ◽  
Accurate Analysis ◽  
Angle Deviation ◽  
Thin Walled

There are unavoidable deviations, such as shrinkage and distortions, in the composite detail parts production due to the complexity of composites fabrication. Interests in the assembly analysis of composite beams have led to a need for more accurate analysis especially in the case of fabrication deviations. This work proposes a numerical finite element model of thin-walled C-section composite beam with R-angle deviation for assembling. The rule of Hashin failure combined with cohesive element is applied to study the mechanical performance of the fiber and matrix (implemented as user subroutine UMAT in ABAQUS) while positioning and clamping. Tension and compression tests are carried out based on available standards to determine the C-section beam behavior under load. The testing data validates the proposed numerical model. The numerical model captures the experimentally obtained results with minimal error, and predicts the failure modes successfully. The proposed model allows to determine accurately the first failure location and the associated load level. It will enhance the understanding of the composite components pre-loading analysis, and help systematically improving the composites assembling efficiency in civil aircraft industry.

Cargo Ride Safety Analysis of Trucks for Four Excitation Cases

2010 ◽  
Vol 118-120 ◽  
pp. 660-664
Author(s):  
Li Qun Guo ◽  
Deng Feng Wang
Keyword(s):  
Element Model ◽  
The Body ◽  
Three Dimension ◽  
Commercial Vehicles ◽  
3D Finite Element ◽  
The Road ◽  
Full Vehicle ◽  
Power Spectral ◽  
Computation Algorithm ◽  
Vertical Accelerations

Excessive levels of vibration in commercial vehicles, due to excitation from the road irregularities, can lead to cargo damage and safety problems. In order to study the cargo ride safety problem, a three dimension (3D) finite element model of full vehicle was established, which differs from the previous two dimension (2D) one. The computation algorithm for acceleration power spectral density (PSD) and root mean square (RMS) was also given. For the sake of comparisons, two frames with different stiffness were given in the computations of PSD and RMS of body vertical accelerations for four excitation cases. The computed results showed that when the stiffness of the frame increases, the RMS values of the body decreases strongly at the frequency band 14-26Hz, which can effectively improve the cargo ride safety.

scholarly journals From Pedagogy to Educational Science: Inspired By Meile (Love)

Pedagogika ◽  
2013 ◽  
Vol 111 (2) ◽  
pp. 53-61
Author(s):  
Palmira Jucevičienė
Keyword(s):  
World Wide ◽  
Educational Practice ◽  
Scientific Discipline ◽  
Educational Process ◽  
The Body ◽  
Educational Science ◽  
The Road ◽  
Body Of Knowledge ◽  
National School ◽  
New Knowledge

Education is sociocultural phenomenon which has significantly influenced the development of the society and also is under the development itself. The complexity of changes experienced by the society generates the challenges for the educational practice and theory. Respectfully – conditioning the needs for the development of the body of knowledge necessary for education and its production. Regaining independence of Lithuania in 1990 opened up new opportunities for educational practice and research in the country. Dr. Meile Luksiene’s works on the Concept of National School inspired researchers and practitioners for educational reform which invited to search for new knowledge in the area of education. Pedagogy, as traditional discipline by itself, researching only the educational process, not the system of education and lifelong learning, was no longer sufficient. Interdisciplinary and most importantly multidisciplinary approaches towards the reality and perspectives of education were necessary. The aim of this article is to reveal the road of the scientific discipline development in Lithuania from pedagogy to educational science on the foundation of both national and world wide trends which have been consistently influencing this development.

A Stellenbosch University #FeesMustFall Herstory: Reflections of a So-Called "Radical Black Intersectional Feminist"

Politeia ◽  
2018 ◽  
Vol 37 (2) ◽  
Author(s):  
Ashanti Kunene
Keyword(s):  
The Body ◽  
Self Reflection ◽  
Body Of Knowledge ◽  
Patriarchal Narratives

#FeesMustFall was a movement whose maxim was, “This revolution will be intersectional, or it will be bullshit.” This article is a self-reflection on my participation as a so-called radical black intersectional feminist in the #FeesMustFall movement at Stellenbosch University. It is also an attempt to provide evidence of the double erasures taking place in the mainstream patriarchal narratives about the #FeesMustFall movement. My story bears witness to the fact that queer black womxn were the backbone of the movement and that #FeesMustFall did indeed occur at Stellenbosch University. These constitute the double erasures taking place in terms of what is and can be known about the #FeesMustFall movement. My reflections serve to make a much-needed contribution to the body of knowledge produced about the #FeesMustFall movement.

Thinking about offender social reintegration: A case study of one NGO programme in the Eastern Cape Province of South Africa

2021 ◽  
pp. 002087282096742
Author(s):  
Emmison Muleya
Keyword(s):  
South Africa ◽  
Crime Prevention ◽  
The Body ◽  
Eastern Cape Province ◽  
Eastern Cape ◽  
Social Reintegration ◽  
Body Of Knowledge ◽  
Former Offenders ◽  
Offender Reintegration

Successful social reintegration is critical if we are to reduce recidivism and crime in general. This voice of people article presents a background case for why effective offender reintegration services are key in South Africa, and the Eastern Cape in particular, through an example of the Offender Reintegration programme rendered by the National Institute of Crime Prevention and Reintegration of Offenders (NICRO). Apart from the paucity of literature on offender reintegration, very few voices from people working directly with these former offenders are ever heard. Therefore, this article seeks to address this gap by contributing to the body of knowledge on offender social reintegration.

scholarly journals How Does Retail Engage Consumers in Sustainable Consumption? A Systematic Literature Review

2020 ◽  
Vol 13 (1) ◽  
pp. 96
Author(s):  
Carmen Bălan
Keyword(s):  
Systematic Review ◽  
Sustainable Consumption ◽  
The Body ◽  
Consumer Engagement ◽  
Academic Literature ◽  
Body Of Knowledge ◽  
Food Retailers ◽  
Retail Marketing ◽  
Marketing Actions

The academic literature on consumer engagement and sustainable consumption has developed gradually over the last two decades. The body of knowledge related to the role of food and non-food retailers in this context, however, is only beginning to develop. The purpose of this systematic review is to analyse the existing literature on how retailers fulfil their role in engaging consumers in sustainable consumption. The need for a study with this purpose is proven by the fact that academic literature lacks a systematic review on this topic, despite the ascending trend in the number of published articles in the field. This systematic review is based on a five-step process to ensure quality, replicability, transparency, and reliable conclusions. The reviewed articles were published relatively recently in academic journals from different domains. This review identified seven distinct types of retail marketing interventions (involvement of retailers in marketing actions with the aim to engage consumers in sustainable consumption), 30 types of retail marketing mechanisms (consisting in marketing strategies, techniques, tools, and channels used by retailers), and 14 distinct types of consumer engagement in sustainable consumption patterns. The review suggests an agenda for further research and identifies practical implications for retail management.

Finite Element Analysis of the Distributed Vibration Absorbers for Structural Noise Control

2005 ◽  
Author(s):  
Ashwini Gautam ◽  
Chris Fuller ◽  
James Carneal
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Base Plate ◽  
Element Model ◽  
Fe Model ◽  
Vibration Absorbers ◽  
Element Analysis ◽  
Poroelastic Media ◽  
Hexahedral Elements ◽  
Component Models

This work presents an extensive analysis of the properties of distributed vibration absorbers (DVAs) and their effectiveness in controlling the sound radiation from the base structure. The DVA acts as a distributed mass absorber consisting of a thin metal sheet covering a layer of acoustic foam (porous media) that behaves like a distributed spring-mass-damper system. To assess the effectiveness of these DVAs in controlling the vibration of the base structures (plate) a detailed finite elements model has been developed for the DVA and base plate structure. The foam was modeled as a poroelastic media using 8 node hexahedral elements. The structural (plate) domain was modeled using 16 degree of freedom plate elements. Each of the finite element models have been validated by comparing the numerical results with the available analytical and experimental results. These component models were combined to model the DVA. Preliminary experiments conducted on the DVAs have shown an excellent agreement between the results obtained from the numerical model of the DVA and from the experiments. The component models and the DVA model were then combined into a larger FE model comprised of a base plate with the DVA treatment on its surface. The results from the simulation of this numerical model have shown that there has been a significant reduction in the vibration levels of the base plate due to DVA treatment on it. It has been shown from this work that the inclusion of the DVAs on the base plate reduces their vibration response and therefore the radiated noise. Moreover, the detailed development of the finite element model for the foam has provided us with the capability to analyze the physics behind the behavior of the distributed vibration absorbers (DVAs) and to develop more optimized designs for the same.

scholarly journals Load Measurement of the Cervical Vertebra C7 and the Head of Passengers of a Car While Driving Across Uneven Terrain

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3849
Author(s):  
Martin Svoboda ◽  
Milan Chalupa ◽  
Karel Jelen ◽  
František Lopot ◽  
Petr Kubový ◽  
...  
Keyword(s):  
Cervical Vertebrae ◽  
Vertical Direction ◽  
Cervical Vertebra ◽  
Parietal Bone ◽  
The Body ◽  
Human Organism ◽  
Dynamic Effects ◽  
The Road ◽  
Real Environment ◽  
On The Road

The article deals with the measurement of dynamic effects that are transmitted to the driver (passenger) when driving in a car over obstacles. The measurements were performed in a real environment on a defined track at different driving speeds and different distributions of obstacles on the road. The reaction of the human organism, respectively the load of the cervical vertebrae and the heads of the driver and passenger, was measured. Experimental measurements were performed for different variants of driving conditions on a 28-year-old and healthy man. The measurement’s main objective was to determine the acceleration values of the seats in the vehicle in the vertical movement of parts of the vehicle cabin and to determine the dynamic effects that are transmitted to the driver and passenger in a car when driving over obstacles. The measurements were performed in a real environment on a defined track at various driving speeds and diverse distributions of obstacles on the road. The acceleration values on the vehicle’s axles and the structure of the driver’s and front passenger’s seats, under the buttocks, at the top of the head (Vertex Parietal Bone) and the C7 cervical vertebra (Vertebra Cervicales), were measured. The result of the experiment was to determine the maximum magnitudes of acceleration in the vertical direction on the body of the driver and the passenger of the vehicle when passing a passenger vehicle over obstacles. The analysis of the experiment’s results is the basis for determining the future direction of the research.

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