Searched for: subject%3A%22Squat%22
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Schächer, Rebekka (author)
The Bananeira Garden (Horta da Bananeira) is a guerrilla garden in the escarpments of Porto that has collectively been created by a group of people with no claim of ownership or fixed identity. These gardeners explicitly refuse to recognize the state’s authority over the forgotten urban spaces in the city. Gardening turns into a political act, a...
master thesis 2023
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Kirschstein, Alex (author)
Urban Paraphrasis imagines urban transformation through the potential of localized material re-use and the capacities of citizen empowerment in the context of Maastricht’s Sphinxkwartier. The project presents an alternative civic center that is built with reclaimed materials from an abandoned clay factory, engages a local community of squatters,...
master thesis 2022
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Determann, Pepijn (author)
The protagonist of this work is the rightless, displaced person - a population of individuals in transition, hidden like a shadow in the contemporary city. Departing from the active oppression of this considerable group from the fabric of the city and the ways in which architecture contributes to enclosing or dividing populations, this work...
master thesis 2021
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Huisman, Jorik (author)
On the railway line between Zutphen and Hengelo in the Netherlands, rolling contact fatigue (RCF) defects are found at the surface of the rail. RCF is a known hazard to the safe operation of railways, the cracks can cause transverse rail fracture, which may result in derailment. Contrary to convention, the traffic on this particular railway is...
master thesis 2021
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Steenbergen, M.J.M.M. (author)
Different origination theories for squat-type rail defects are examined and confronted with experimental evidence. Based on the morphology of the three-dimensional defect crack pattern, with a leading crack directivity governed by the tangential stress history, it is shown that theories assuming dynamic wheel-rail interaction as a direct...
journal article 2021
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Naeimi, M. (author)
Rolling contact fatigue (RCF) is an important form of damage in wheels and rails that typically has surface and subsurface cracks. Squats are one of the major RCF defects that occur in the running band of rails and can create high dynamic forces and cause rail fracture if they are not detected and treated in time. In the current research, three...
doctoral thesis 2020
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Naeimi, M. (author), Li, Z. (author), Dollevoet, R.P.B.J. (author)
This study investigates the angles θ<sub>1</sub>, θ<sub>2</sub>, and θ<sub>3</sub> that squat crack faces form with respect to three orthogonal planes: the rail top, the longitudinal-vertical cross-section and the lateral-vertical cross-section. Rail samples with squats of various severities are obtained from the field. Their three...
journal article 2020
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Deng, X. (author), Li, Z. (author), Qian, Zhiwei (author), Zhai, Wanming (author), Xiao, Qian (author), Dollevoet, R.P.B.J. (author)
Weld-induced squats are a major damage type in high-speed railways as well as in conventional railways. They incur high maintenance costs and endanger operational safety. This paper first presents and analyzes five-year continual field monitoring observations and measurements of squats at rail welds. A hypothesis of the formation and development...
journal article 2019
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Deng, X. (author), Qian, Zhiwei (author), Li, Z. (author), Dollevoet, R.P.B.J. (author)
Rail squats originate from a number of sources, such as corrugations, indentations and welds. A five-year continual field monitoring study was performed on squats induced by corrugations. This study indicated that a small black depression formed at the corrugation under wheel-rail dynamic forces, and then, a primary crack typically initiated...
journal article 2018
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Steenbergen, M.J.M.M. (author)
Spalling defects of a periodic nature are sometimes observed on heat-treated pearlitic steel rails. Defect properties suggest a relationship between maintenance grinding on a regular basis and the initiation of rolling contact fatigue (RCF). In this work, the effects of maintenance grinding are investigated experimentally for both standard...
journal article 2016
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Li, Z. (author), Zhao, X. (author), Dollevoet, R.P.B.J. (author)
A methodology for the determination of a critical size of surface defects, above which RCF can initiate, has been developed and demonstrated with its application to the passive type of squats under typical Dutch railway loading conditions. Such a methodology is based on stress evaluation of transient rolling contact at the defects, for which...
journal article 2016
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Jamshidi, A. (author), Nunez, Alfredo (author), Molodova, M. (author), Li, Z. (author), Dollevoet, R.P.B.J. (author)
conference paper 2016
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Naeimi, M. (author), Li, Z. (author), Petrov, R.H. (author), Dollevoet, R.P.B.J. (author), Sietsma, J. (author), Wu, J. (author)
The substantial similarity of fatigue mechanism in a new test rig for rolling contact fatigue (RCF) has been investigated. A new reduced-scale test rig is designed to perform controlled RCF tests in wheel-rail materials. The fatigue mechanism of the rig is evaluated in this study using a combined finite element-fatigue prediction approach. The...
conference paper 2014
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Deng, X. (author), Naeimi, M. (author), Li, Z. (author), Qian, Z. (author)
A modeling procedure to predict the residual fatigue life of rail at squats seeds is developed in this article. Two models are involved: a 3D explicit Finite Element (FE) model to compute the stress and strain at squats in rail, and the J-S fatigue damage model to determine the residual fatigue life on the basis of the computed stress and strain...
conference paper 2014
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Belletti, B. (author), Esposito, R. (author), Damoni, C. (author)
The paper adopts the FEM to describe the behaviour of a squat shear wall subjected to monotonic loading conditions. Nonlinear finite element analyses (NLFEA) have been performed with the model, denoted as PARC_CL, implemented at the University of Parma in the user’s subroutine UMAT.for for the ABAQUS Code. The PARC_CL model, suitable for...
conference paper 2013
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Molodova, M. (author)
This thesis discusses a new method for detection of short track irregularities, particularly squats, with axle box acceleration (ABA) measurements. A squat is a surface initiated short track defect, associated with high frequency vibrations of the wheel-rail system. High stresses in the contact patch at squats cause accumulation of plastic...
doctoral thesis 2013
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Zhao, X. (author)
Squats, as a kind of short wavelength rail surface defects, have become one of the main rolling contact fatigue problems in railways worldwide. The purpose of this work is to better understand the squatting phenomenon, contribute to reduction and even prevention of squat occurrence, and thereby reduce the related costs. To such an end, a new...
doctoral thesis 2012
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Lenselink, R.J. (author)
An explorative study to investigate flow velocities and sediment transport caused by the passage of a barge train over a small sandy shoal.
master thesis 2011
Searched for: subject%3A%22Squat%22
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