Discrete element model calibration based on in situ measurements

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Istvan Keppler ◽  
Adrienn Bablena ◽  
Nihal D. Salman ◽  
Péter Kiss
Keyword(s):  
Model Calibration ◽  
Design Methodology ◽  
Shear Test ◽  
Element Model ◽  
Discrete Element ◽  
Discrete Element Model ◽  
Content Type ◽  
Vane Shear Test ◽  
Using Data

PurposeTransportation of the measurement samples from their original place to the measurement site causes significant changes in their mechanical properties. The possibility of making in situ measurements helps to create more precise discrete element models.Design/methodology/approachThe possibility of using in situ modified vane shear test based measurement for the calibration of discrete element models is demonstrated in this work.FindingsThe advantage of employing the adjusted vane test is that the values of in situ measurements can be used for the calibration.Originality/valueThe procedure we present allows us to perform accurate discrete element calibration using data from on-site measurements that can be performed quickly and easily.

Hedonic experiences at heritage attractions: the visitor’s perspective

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ana Carolina Bender ◽  
Manuela Guerreiro ◽  
Bernardete Dias Sequeira ◽  
Júlio Mendes
Keyword(s):  
Design Methodology ◽  
Theory And Practice ◽  
Structured Interviews ◽  
Content Type ◽  
Heritage Sites ◽  
Exploratory Approach ◽  
Hedonic Experience ◽  
Using Data

Purpose The purpose of this study is to explore the hedonic experience and its formation at heritage attractions. Design/methodology/approach A qualitative and exploratory approach was applied, using data from 21 semi-structured interviews and three in-situ focus groups. Findings Findings highlight that senses, imagery and emotions are stimulated by the physical landscape and by triggers of memorable experiences. Research limitations/implications To further explore this topic, a broader range of heritage attractions and perspectives from the diverse stakeholders involved in the management and consumption of these sites is needed. Originality/value Given the scarcity of research dedicated to the hedonic experience at heritage sites, this study provides a contribution by exploring the visitor’s perspective and points out relevant insights. As the hedonic feelings of pleasure, comfort and related affective responses impact the quality of memorable experiences, relevant implications for theory and practice are discussed.

A spherical discrete element model: calibration procedure and incremental response

2009 ◽  
Vol 11 (5) ◽  
pp. 293-306 ◽  
Author(s):  
Jean-Patrick Plassiard ◽  
Noura Belheine ◽  
Frédéric-Victor Donzé
Keyword(s):  
Model Calibration ◽  
Element Model ◽  
Discrete Element ◽  
Calibration Procedure ◽  
Discrete Element Model

scholarly journals Discrete element model for general polyhedra

2021 ◽  
Author(s):  
Alfredo Gay Neto ◽  
Peter Wriggers
Keyword(s):  
Frictional Contact ◽  
Virtual Work ◽  
Particle Surface ◽  
Element Model ◽  
Discrete Element ◽  
Discrete Element Model ◽  
Principle Of Virtual Work ◽  
Dynamics Model ◽  
Railway Ballast ◽  
Multibody Dynamics Model

AbstractWe present a version of the Discrete Element Method considering the particles as rigid polyhedra. The Principle of Virtual Work is employed as basis for a multibody dynamics model. Each particle surface is split into sub-regions, which are tracked for contact with other sub-regions of neighboring particles. Contact interactions are modeled pointwise, considering vertex-face, edge-edge, vertex-edge and vertex-vertex interactions. General polyhedra with triangular faces are considered as particles, permitting multiple pointwise interactions which are automatically detected along the model evolution. We propose a combined interface law composed of a penalty and a barrier approach, to fulfill the contact constraints. Numerical examples demonstrate that the model can handle normal and frictional contact effects in a robust manner. These include simulations of convex and non-convex particles, showing the potential of applicability to materials with complex shaped particles such as sand and railway ballast.

Investigation on the shaft voltage generation of large synchronous turboalternators

2020 ◽  
Vol 39 (5) ◽  
pp. 1145-1156
Author(s):  
Kevin Darques ◽  
Abdelmounaïm Tounzi ◽  
Yvonnick Le-menach ◽  
Karim Beddek
Keyword(s):  
Finite Element ◽  
Design Methodology ◽  
Short Circuit ◽  
Element Model ◽  
Stator Winding ◽  
Content Type ◽  
Voltage Generation ◽  
The Impact ◽  
Investigation Process ◽  
Circulating Currents

Purpose This paper aims to go deeper on the analysis of the shaft voltage of large turbogenerators. The main interest of this study is the investigation process developed. Design/methodology/approach The analysis of the shaft voltage because of several defects is based on a two-dimensional (2D) finite element modeling. This 2D finite element model is used to determine the shaft voltage because of eccentricities or rotor short-circuit. Findings Dynamic eccentricities and rotor short circuit do not have an inherent impact on the shaft voltage. Circulating currents in the stator winding because of defects impact the shaft voltage. Originality/value The original value of this paper is the investigation process developed. This study proposes to quantify the impact of a smooth stator and then to explore the contribution of the real stator winding on the shaft voltage.

Study on Machining Mechanism of Glass Using Discrete Element Method

2014 ◽  
Vol 577 ◽  
pp. 108-111 ◽  
Author(s):  
Ying Qiu ◽  
Mei Lin Gu ◽  
Feng Guang Zhang ◽  
Zhi Wei
Keyword(s):  
Discrete Element Method ◽  
Element Model ◽  
Discrete Element ◽  
Rake Angle ◽  
Milling Process ◽  
Micro Milling ◽  
Discrete Element Model ◽  
Machined Surface ◽  
Damage Depth ◽  
Element Method

The discrete element method (DEM) is applied to glass micromachining in this study. By three standard tests the discrete element model is established to match the main mechanical properties of glass. Then, indentating, cutting, micro milling process are simulated. Results show that the vertical damage depth is prevented from reaching the final machined surface in cutting process. Tool rake angle is the most remarkable factor influencing on the chip deformation and cutting force. The final machined surface is determined by the minimum cutting thickness per edge. Different cutting thickness, cutter shape and spindle speed largely effect on the mechanism of glass.

Risk-based capital regulation revisited: evidence from the early 2000s

2015 ◽  
Vol 23 (2) ◽  
pp. 115-134 ◽  
Author(s):  
Thomas L. Hogan ◽  
Neil R. Meredith ◽  
Xuhao (Harry) Pan
Keyword(s):  
Design Methodology ◽  
Banking Regulation ◽  
Bank Performance ◽  
Capital Regulation ◽  
Data Set ◽  
Content Type ◽  
Future Performance ◽  
Capital Ratios ◽  
Using Data ◽  
Capital Regulations

Purpose – The purpose of this study is to replicate Avery and Berger’s (1991) analysis using data from 2001 through 2011. Although risk-based capital (RBC) regulation is a key component of US banking regulation, empirical evidence of the effectiveness of these regulations has been mixed. Among the first studies of RBC regulation, Avery and Berger (1991) provide evidence from data on US banks that new RBC regulations outperformed old capital regulations from 1982 through 1989. Design/methodology/approach – Using data from the Federal Reserve’s Call Reports, the authors compare banks’ capital ratios and RBC ratios to five measures of bank performance: income, standard deviation of income, non-performing loans, loan charge-offs and probability of failure. Findings – Consistent with Avery and Berger (1991), the authors find banks’ risk-weighted assets to be significant predictors of their future performance and that RBC ratios outperform regular capital ratios as predictors of risk. Originality/value – The study improves on Avery and Berger (1991) by using an updated data set from 2001 through 2011. The authors also discuss some potential limitations of this method of analysis.

Policing in the COVID-19 pandemic: are rural police organizations immune?

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Thomas J. Mrozla
Keyword(s):  
Design Methodology ◽  
The United States ◽  
Content Type ◽  
Public Health Emergencies ◽  
Police Organizations ◽  
Police Agencies ◽  
Health Tracking ◽  
Rural Police ◽  
Using Data ◽  
Practical Implications

PurposeThis study examined how rural police agencies have responded to the COVID-19 pandemic.Design/methodology/approachUsing data from various sources, this study first analyzed what factors influenced agency preparedness to respond to pandemics. Second, it examined how the pandemic influenced specific organizational practices.FindingsFindings revealed that as coronavirus infections increased in counties, supervisors were more likely be tasked with inspecting personal protective equipment (PPE), agencies were more likely to offer pandemic related training, health tracking of officers was more likely to occur and agencies were more likely to encounter a shortage of officers. In addition, as rurality increased, agencies were more likely to offer training but less likely to experience officers contracting COVID-19 and an officer shortage. Lastly, as the rurality of the county in which the agency resides increased, the ability to supply PPE decreased.Practical implicationsBased on these findings, it is imperative that rural police agencies give attention to risk management and the formulation of policy to prepare for public health emergencies.Originality/valueWhile knowledge about how large police agencies in the United States have responded during the coronavirus pandemic is building, little is known about rural policing during pandemics.

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