Effect of Longitudinal Fastener Stiffness on Fastening System Loading - Initial Findings

2021 ◽  
Author(s):  
Christian J. Khachaturian ◽  
Marcus S. Dersch ◽  
J. Riley Edwards ◽  
Matheus Trizotto
Keyword(s):  
North America ◽  
Analytical Model ◽  
Fatigue Failure ◽  
Analytical Method ◽  
Vertical Load ◽  
Stress Concentrations ◽  
Laboratory Experimentation ◽  
The Past ◽  
Track Stiffness ◽  
Fatigue Failures

Abstract Over the past 20 years, there have been at least 10 derailments due to spike fatigue failures in North America. Researchers believe that fatigue failure is caused by a combination of lateral and longitudinal spike loading. The literature indicates the vertical load and fastener friction must be considered when estimating failure locations. Though the in-track vertical, lateral, and longitudinal fastener forces have been quantified at a location that has experienced spike failures, there is a need to account for additional fasteners and track locations. Fastening systems can affect track stiffness, thus, laboratory experimentation was performed to quantify stiffness of multiple fastening systems. This data was input into an analytical model which quantified the effect of stiffness on longitudinal fastener loading. The data indicate there is significant variance in fastening system stiffness within, and between, systems. However, this variation in fastener stiffness has a reduced effect on the load transferred to the fastening system. More work is needed to validate this in the lab or field given variability within a system could lead to stress concentrations that are not fully captured using the current idealized analytical method.

scholarly journals Remnant and the New Dark Age

Religions ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 372
Author(s):  
Edward Rommen
Keyword(s):  
North America ◽  
Moral Discourse ◽  
The Past ◽  
Personal Opinion

A new dark age has come upon us; as a result, Christianity and its churches in North America are no longer growing. One reason for this might be the widespread impression that Christians are hypocrites, saying they believe one thing while doing the opposite. However, that accusation would only be true if these believers actually believed the principles they are supposed to be violating. It is more likely that many Christians have, like those around them, abandoned truth in favor of personal opinion bringing moral discourse to a near standstill and intensifying the darkness by extinguishing the light of truth. Still, there is hope. In the past, it often was a faithful few, a remnant, who preserved the knowledge of that light and facilitated a new dawn. History shows us that the very movements that are today abdicating responsibility were once spiritual survivors themselves. They withdrew, coalesced around the remaining spark of truth in order to remember, preserve, and reignite. The thoughts and practices of these pioneers could guide the escape from today’s darkness.

scholarly journals Scoot over Smart Devices: The Invisible Costs of Rental Scooters

2019 ◽  
Vol 17 (1/2) ◽  
pp. 191-197 ◽  
Author(s):  
Andrew Boyles Petersen
Keyword(s):  
North America ◽  
Data Security ◽  
Mobile Apps ◽  
Smart Devices ◽  
Gps Data ◽  
Security Risks ◽  
The Past ◽  
Last Mile ◽  
User Data ◽  
Consumer Data

In the past year, transportation rental companies, including Bird, Lime, and Spin, have dropped hundreds of thousands of rental scooters across North America. Relying on mobile apps and scooter-mounted GPS units, these devices have access to a wide-variety of consumer data, including location, phone number, phone metadata, and more. Pairing corroborated phone and scooter GPS data with a last-mile transportation business model, scooter companies are able to collect a unique, highly identifying dataset on users. Data collected by these companies can be utilized by internal researchers or sold to advertisers and data brokers. Access to so much consumer data, however, poses serious security risks. ­Although Bird, Lime, and Spin posit electric scooters as environmentally friendly and accessible transportation, they also allow for unethical uses of user data through vaguely-worded terms of service. To promote more equitable transportation practices, this article will explore the implications of dockless scooter geotracking, as well as related infrastructure, privacy, and data security ramifications.

scholarly journals Multi-stable composite twisting structure for morphing applications

2012 ◽  
Vol 468 (2141) ◽  
pp. 1230-1251 ◽  
Author(s):  
X. Lachenal ◽  
P. M. Weaver ◽  
S. Daynes
Keyword(s):  
Analytical Model ◽  
Material Properties ◽  
Degrees Of Freedom ◽  
Design Parameters ◽  
Engineering Structures ◽  
The Past ◽  
Wide Range ◽  
Morphing Structure ◽  
Low Mass ◽  
Unstable States

Conventional shape-changing engineering structures use discrete parts articulated around a number of linkages. Each part carries the loads, and the articulations provide the degrees of freedom of the system, leading to heavy and complex mechanisms. Consequently, there has been increased interest in morphing structures over the past decade owing to their potential to combine the conflicting requirements of strength, flexibility and low mass. This article presents a novel type of morphing structure capable of large deformations, simply consisting of two pre-stressed flanges joined to introduce two stable configurations. The bistability is analysed through a simple analytical model, predicting the positions of the stable and unstable states for different design parameters and material properties. Good correlation is found between experimental results, finite-element modelling and predictions from the analytical model for one particular example. A wide range of design parameters and material properties is also analytically investigated, yielding a remarkable structure with zero stiffness along the twisting axis.

Summary of Coastal Geologic Evidence for past Great Earthquakes at the Cascadia Subduction Zone

1995 ◽  
Vol 11 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Brian F. Atwater ◽  
Alan R. Nelson ◽  
John J. Clague ◽  
Gary A. Carver ◽  
David K. Yamaguchi ◽  
...  
Keyword(s):  
British Columbia ◽  
North America ◽  
Subduction Zone ◽  
Forest Soils ◽  
Pacific Coast ◽  
Cascadia Subduction Zone ◽  
Level Change ◽  
The Past ◽  
The Pacific ◽  
Juan De Fuca

Earthquakes in the past few thousand years have left signs of land-level change, tsunamis, and shaking along the Pacific coast at the Cascadia subduction zone. Sudden lowering of land accounts for many of the buried marsh and forest soils at estuaries between southern British Columbia and northern California. Sand layers on some of these soils imply that tsunamis were triggered by some of the events that lowered the land. Liquefaction features show that inland shaking accompanied sudden coastal subsidence at the Washington-Oregon border about 300 years ago. The combined evidence for subsidence, tsunamis, and shaking shows that earthquakes of magnitude 8 or larger have occurred on the boundary between the overriding North America plate and the downgoing Juan de Fuca and Gorda plates. Intervals between the earthquakes are poorly known because of uncertainties about the number and ages of the earthquakes. Current estimates for individual intervals at specific coastal sites range from a few centuries to about one thousand years.

Fatigue behaviour of Vossloh SKL14 tension clamps

2021 ◽  
Author(s):  
Bohumil Culek ◽  
Eva Schmidová ◽  
Petr Tomek ◽  
Petr Vnenk ◽  
Marek Pětioký
Keyword(s):  
Service Life ◽  
Fatigue Failure ◽  
Critical Points ◽  
Fatigue Curve ◽  
Fatigue Behaviour ◽  
Fractographic Analysis ◽  
Railway Track ◽  
Strain Gauges ◽  
Dynamically Loaded ◽  
Fatigue Failures

<p>The reliability of the railway superstructure depends, among other things, on the actual fastening of the rail to the sleepers. This structure is extremely dynamically loaded. In the paper, the attention is paid to the flexible Vossloh W14 fastening system with the use of SKL14 tension clamps. These clamps are often damaged by fatigue failures, especially in curves of small radii (R &lt; 400 m). Within the research, fracture areas were identified and a fractographic analysis was performed. The analysis proved fatigue failure and, therefore, an estimation of the service life of the clamps was made. The evaluation was focused on a selected area of railway track where the fatigue-damaged clamps were found. The strain gauges were placed directly on the clamps at critical points and the obtained values were confronted with the experimentally obtained fatigue curve. Based on the presented findings, the service life of the clamps in the selected track was identified.</p>

Measurement of Thermal Conductivity of a Flexible Substrate

2014 ◽  
Author(s):  
Vivek Vishwakarma ◽  
Ankur Jain
Keyword(s):  
Thermal Conductivity ◽  
Analytical Model ◽  
Flexible Substrate ◽  
Thermal Response ◽  
Experimental Methodology ◽  
Plastic Substrate ◽  
The Past ◽  
Thin Plastic ◽  
Transient Thermal ◽  
Transient Thermal Response

A number of past papers have described experimental techniques for measurement of thermal conductivity of substrates and thin films of technological interest. Nearly all substrates measured in the past are rigid. There is a lack of papers that report measurements on a flexible substrate such as thin plastic. The paper presents an experimental methodology to deposit a thin film microheater device on a plastic substrate. This device, comprising a microheater line and a temperature sensor line is used to measure the thermal conductivity of the plastic substrate using the transient thermal response of the plastic substrate to a heating current. An analytical model describing this thermal response is presented. Thermal conductivity of the plastic substrate is determined by comparison of experimental data with the analytical model. Results described in this paper may aid in development of an understanding of thermal transport in flexible substrates.

The role of horizontal thermal advection in regulating wintertime mean and extreme temperatures over interior North America during the past and future

2019 ◽  
Vol 53 (9-10) ◽  
pp. 6125-6144
Author(s):  
Fuyao Wang ◽  
Stephen J. Vavrus ◽  
Jennifer A. Francis ◽  
Jonathan E. Martin
Keyword(s):  
North America ◽  
Extreme Temperatures ◽  
Thermal Advection ◽  
The Past

Value of Bootstrapping Staged Deployment of Infrastructure: Case Study in Space Infrastructure Deployment

2017 ◽  
Author(s):  
Koki Ho ◽  
Hao Chen ◽  
Harrison Kim
Keyword(s):  
Analytical Model ◽  
Analytical Method ◽  
Space Exploration ◽  
Optimal Number ◽  
Single Stage ◽  
Operational Planning ◽  
Uncertain Environment ◽  
Infrastructure System ◽  
Space Infrastructure

This paper analyzes the value of staged deployment for complex infrastructure system and propose a concept of bootstrapping staged deployment. Staged deployment has been well known for its advantage of providing flexibility in an uncertain environment. In contrast, this paper demonstrates that the proposed bootstrapping staged deployment can even add values in a deterministic environment. The key idea of bootstrapping staged deployment is to have the previously deployed stages support the subsequent deployment. We develop an analytical model to demonstrate the effects of bootstrapping staged deployment with a case study in space exploration. Our analysis results show that with a well-coordinated deployment plan, staged deployment can overperform single-stage deployment even in a deterministic environment, and that there is an optimal number of stages in terms of lifecycle cost under certain conditions. Our method can find the analytical expression for the optimal number of stages and its deployment strategies. The general findings from the proposed concept and analytical method can advance our knowledge about systems staged deployment, and make operational planning of resource generation infrastructure more efficient.

scholarly journals A Magical Reorientation of the Modern: Professional Organizers and Thingly Care in Contemporary North America

2016 ◽  
Vol 31 (3) ◽  
pp. 438-457 ◽  
Author(s):  
Katie Kilroy-Marac
Keyword(s):  
North America ◽  
Mental Disorder ◽  
North American ◽  
Popular Media ◽  
Hoarding Disorder ◽  
The Past ◽  
The North ◽  
Dsm V ◽  
Double Movement ◽  
Domestic Variety

Within the past decade, material disorder—especially that of the domestic variety—has come to stand alternately as evidence, symptom, and potential cause of mental disorder in the North American popular and psychiatric imagination. Sources ranging from the newly defined Hoarding Disorder diagnosis in the DSM-V, to popular media, to agents of the burgeoning clutter-management industry describe disorder in terms of an irrational attachment, closeness, or overidentification with objects. At the same time, these sources imagine order to result from the cool distance and controlled passion a person is able to maintain toward his or her possessions. Drawing on more than twenty interviews and numerous fieldwork encounters with professional organizers (POs) in Toronto between 2014 and 2015, this article describes how POs aim to reorient their clients materially, morally, and affectively to relieve the disorder they report in their lives. Here, I argue, POs emerge as a species of late capitalist healer whose interventions are animated by a paradoxical double movement. For just as POs act to loosen the object attachments and disrupt the “secret sympathy” their clients share with their possessions, they operate within a realm of magical correspondence where matter and mind are imagined to reflect and affect one another, and where bringing order to a client’s possessions means also bringing order to his or her mind.

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