Side Impact Testing and Analyses of Unpressurized Tank Cars

Author(s):  
Steven W. Kirkpatrick ◽  
Robert A. MacNeill ◽  
Francisco Gonzalez ◽  
Przemyslaw Rakoczy

There has been significant research in recent years to analyze and improve the impact behavior and puncture resistance of railroad tank cars. Ultimately, the results of this work will be used by the Government regulatory agencies in the United States and Canada to establish performance-based testing requirements and to develop methods to evaluate the crashworthiness and structural integrity of different tank car designs. This paper describes results of recent side impact testing and corresponding analyses using detailed finite element analyses (FEA). The test and analyses were performed to evaluate the side impact puncture performance of DOT-111 tank cars. The tank car was filled with water to approximately 97 percent of the volume. The tank was then sealed but not pressurized. The tank car was impacted at the Transportation Technology Center, Inc. by a 297,125-pound ram car with 12-by 12-inch ram head fitted to the ram car impacted the tank center. The analyses were on overall good agreement with the measured impact response. The lading was found to play a more significant role in the impact response than in previous testing and analyses of pressure tank cars. This is not surprising considering the reduced structural stiffness of the tanks compared to thicker pressure tank cars and the reduced effective stiffness from the initially unpressurized tank at impact. The smaller outage volume also contributes to a dramatic increase in the tank pressure as the dent formation reduces the tank volume and compresses the contents of the tank.

Author(s):  
Steven W. Kirkpatrick ◽  
Robert A. MacNeill ◽  
Francisco Gonzalez

There has been significant research in recent years to analyze and improve the impact behavior and puncture resistance of railroad tank cars. Ultimately, the results of this work will be used by the Government regulatory agencies in the United States and Canada to establish performance-based testing requirements and to develop methods to evaluate the crashworthiness and structural integrity of different tank car designs. This paper describes analyses of current impact testing requirements and impact test methodologies using detailed finite element analyses (FEA). The results of these analyses are used to identify characteristics of the test methodologies that are desirable or undesirable for the test requirements in future tank car safety regulations.


Author(s):  
V. Patlolla ◽  
J. George ◽  
Soo-Han Loo ◽  
R. Asmatulu

The purpose of this research was to determine the influence of material properties on the impact response of a laminate, whereby specimens were fabricated and cured under a vacuum and high temperature using three types of pre-impregnated (prepreg), carbon fibers, namely unidirectional fiber, plain weave woven fiber, and non-crimp fiber (NCF). Each carbon fiber panel, usually known for its low-impact properties, of 16 plies underwent impact testing using a low-velocity impactor and visual damage inspection by C-scan in order to measure the damage area and depth, before and after impact testing. These panels were treated with UV exposure and moisture conditioning for 20 days each. Water contact angles were taken into consideration to determine the hydrophobicity and hydrophillicity of the respective prepreg materials. Experimental results and damage analysis showed that UV exposure and moisture conditioning showcased the variation in impact response and behavior, such as load-carrying capacity, absorbed energy, and impact energy of the carbon fiber panels. This study illustrates that non-crimp carbon fiber laminates were far more superior relative to load capacity than woven and unidirectional laminates, with the NCF-AS laminate exhibiting the highest load capacity of 17,244 lb/in (pre-UV) with only 0.89% decrease after UV exposure. This same laminate also had a 1.54% decrease in sustaining impact and 31.4% increase in wettability of the panel. Moreover, the study shows how symmetric and asymmetric stacking sequences affect the impact behavior of non-crimp fiber laminates. These results may be useful for expanding the capacity of carbon fiber, lowering costs, and growing new markets, thus turning carbon fiber into a viable commercial product.


2018 ◽  
Vol 51 (1) ◽  
pp. 64-74 ◽  
Author(s):  
Akar Dogan ◽  
Yusuf Arman

In this study, the effects of temperature and impactor nose diameter on the impact behavior of woven glass-reinforced polyamide 6 (PA6) and polypropylene (PP) thermoplastic composites were investigated experimentally. Impact energies are chosen as 10, 30, 50, 70, 90, 110, 130, and 170 J. The thickness of composite materials is 4 mm. Impact tests were performed using a drop weight impact testing machine, CEAST-Fractovis Plus, and the load capacity of test machine is 22 kN. Hemispherical impactor nose diameter of 12, 7, and 20 mm were used as an impactor. The tests are conducted at room temperature (20°C and 75°C). As a result, the PP composites of the same thickness absorbed more energy than PA6 composites. The amount of absorbed energy of PP and PA6 composites decreased with temperature.


2012 ◽  
Vol 25 (1) ◽  
pp. 149-156
Author(s):  
PAUL S. REICHLER

AbstractThe Nicaragua case demonstrates the Court's competence in receiving and interpreting evidence, and in making reasoned findings of fact, even in the most complicated evidentiary context, as is often presented in cases involving use of force and armed conflict. The Court applied well-established standards for evaluating the conflicting evidence presented to it. In particular, the Court determined that greater weight should be given to statements against interest made by high-level government officials than to a state's self-serving declarations. The Court also determined that statements by disinterested witnesses with first-hand knowledge should receive greater weight than mere statements of opinion or press reports. In applying these guidelines, the Court found, correctly, that (i) the United States had used military and paramilitary force against Nicaragua both directly and indirectly, by organizing, financing, arming, and training the Contra guerrillas to attack Nicaragua; (ii) the evidence did not support a finding that the United States exercised direct control over the Contras’ day-to-day operations; and (iii) there was no evidence that Nicaragua supplied arms to guerrillas fighting against the government of El Salvador during the relevant period, or carried out an armed attack against that state. While Judge Schwebel's dissent criticized the last of these findings, in fact, the evidence fully supported the Court's conclusion. In subsequent decisions during the past 25 years, the Court has continued to rely on the approach to evidence first elaborated in the Nicaragua case and has continued to demonstrate its competence as a finder of fact, including in cases involving armed conflict (Bosnia Genocide) and complex scientific and technical issues (Pulp Mills).


Ekonomika ◽  
2015 ◽  
Vol 93 (4) ◽  
pp. 85-118 ◽  
Author(s):  
Vaidotas Pajarskas ◽  
Aldona Jočienė

The main purpose of this article is to determine which factors and how contributed to the subprime mortgage crisis in the United States in 2007–2008, what their causal links and effects on the markets and the whole economy were, and to assess what actions could have been taken by the Federal Reserve and the Government in order to mitigate or prevent the consequences of subprime mortgage crisis and housing bubble. In order to obtain the research results, the authors performed a qualitative analysis of the scientific literature on the course of events and their development that led to the subprime mortgage crisis, and focused on the insufficiently regulated home mortgage market expansion, the impact on the subprime mortgage crisis of financial innovations and financial engineering, poorly evaluated systemic risks and policy undertaken by both the U.S. Government and the Federal Reserve before and after the crisis. The quantitative research focused on two main parts: firstly, analysis of the dependence between the causes of subprime mortgage crisis and the consequences, using a statistical and regression analysis, and secondly, an alternative path the Government and the Federal Reserve could have taken in their policy actions and the results they could have produced. The authors believe that the results of the research could give useful guidelines to the central bankers and government officials on how to make long-term decisions that can help in preparing for the financial distress, mitigating the consequences when the crisis strikes, accelerating the recovery and even preventing the crisis it in the future. The second part of the qualitative research will appear in the next issue of the journal.


2021 ◽  
Vol 6 (2) ◽  
Author(s):  
Ahmad Shah Azami

As part of its “War on Terror”, the United States (US) provided immense sums of money and advanced equipment to Afghan warlords in order to defeat and dismantle the Taliban and al-Qaeda in Afghanistan. Nearly two decades after the 2001 US-led intervention in Afghanistan that toppled the Taliban regime, the US continues supporting the warlords in various ways. As the intervention was also aimed at establishing a functioning state and reconstruction of the war-torn country, the US needed the support of local warlords to achieve its goals. However, over time, warlords and warlordism became a major challenge to the postTaliban state-building project and in many ways undermined the overall security and the state monopoly on violence. These warlords, who had been mostly expelled and defeated by the Taliban regime, returned under the aegis of the B52 bombers, recaptured parts of the country and reestablished their fiefdoms with US support and resources. They not only resist giving up the power and prestige they have accumulated over the past few years, but also hamper the effort to improve governance and enact necessary reforms in the country. In addition, many of them run their private militias and have been accused of serious human rights abuses as well as drug trafficking, arms smuggling, illegal mining and extortion in the areas under their control or influence. In many ways, they challenge the government authority and have become a major hurdle to the country’s emerging from lawlessness and anarchy. This paper explores the emergence and reemergence of warlords in Afghanistan as well as the evolution of chaos and anarchy in the country, especially after the US-led intervention of late 2001. It also analyzes the impact of the post-9/11 US support to Afghan warlords and its negative consequences for the overall stability and the US-led state-building process in Afghanistan.


2018 ◽  
Vol 183 ◽  
pp. 02040
Author(s):  
KarthikRam Ramakrishnan ◽  
Mikko Hokka ◽  
Essi Sarlin ◽  
Mikko Kanerva ◽  
Reijo Kouhia ◽  
...  

Recent developments in the production of technical flax fabrics allow the use of sustainable natural fibres to replace synthetic fibres in the manufacture of structural composite parts. Natural fibre reinforced biocomposites have been proven to satisfy design and structural integrity requirements but impact strength has been identified as one of their limitations. In this paper, hybridisation of the biocomposite with a metal layer has been investigated as a potential method to improve the impact resistance of natural fibre composites. The impact response of biocomposites made of flax-epoxy is investigated experimentally using a high velocity particle impactor. A high-speed camera setup was used to observe the rear surface of the plates during impact. Digital Image Correlation (DIC) of the high speed camera images was used for full-field strain measurement and to study the initiation and propagation of damage during the impact. The different modes of damage in the hybrid laminate were identified by postimpact analysis of the section of the damaged composite plate using optical microscopy. The study shows the difference in impact response for different material combinations and configurations. The hybrid construction was shown to improve the impact resistance of the flax composite.


Author(s):  
Zegbeh C. Jallah ◽  
Pamela Moalli ◽  
Andrew Feola ◽  
William Barone ◽  
Stacy Palcsey ◽  
...  

Pelvic organ prolapse (POP) is a multifactorial disorder characterized by the descent of the pelvic organs into the vaginal canal. This disorder is associated with decreased quality of life, and even depression, yet 50% of women over the age of fifty are living with POP. The cost associated with the repair of POP exceeds one billion dollars annually, in the United States alone. This rather exorbitant figure includes the cost of surgery performed for symptom management, but does not include strategies which address the underlying cause of the disorder for which there are none. Because failure rates of native tissue repairs are as high as 30%, vaginal mesh is increasingly used in the surgical repair of POP. The procedure aims to reinforce the fibromuscular layer of the vagina and the paravaginal attachments, thus providing structural integrity to the weakened native tissues. However, the use of mesh is limited by mesh-related complications including exposure, erosion, pain contraction and infection.


2004 ◽  
Vol 56 (1) ◽  
pp. 45-60 ◽  
Author(s):  
Douglas M. Thompson ◽  
Gregory N. Stull

Abstract The use of instream structures to modify aquatic habitat has a long history in the United States. Pioneering work by wealthy landowners in the Catskills region of New York produced a range of designs in the decades preceding the Great Depression in an effort to replenish fish populations depleted from overfishing. The scientific evaluation of structures began in 1930. Within two years, a Michigan research team claimed improved fish populations. Cheap labor and government-sponsored conservation projects spearheaded by the Civilian Conservation Corps allowed the widespread adoption of the techniques in the 1930s, before adequate testing of the long-term impact of the devices. The start of World War II temporarily ended the government conservation efforts and prevented the continued evaluation of structures. During the 1940s, 1950s and 1960s, designs of instream structures remained essentially unchanged. Meanwhile, the small number of evaluations of the impact of the structures often were flawed. The continued use of early designs of instream structures helped instill a false belief that instream structures were proven to be a benefit to fish. Even modern use of instream structures continues to rely on the basic blueprints developed in the Catskills, despite documented problems with the use of these designs.


Author(s):  
Davoud Ghahremanlou ◽  
Wieslaw Kubiak

Environmental concerns and energy security have led governments to establish legislations to convertConventional Petroleum Supply Chain (CPSC) to Sustainable Petroleum Supply Chain (SPSC). The United States(US), one of the biggest oil consumers in the world, has created regulations to manage ethanol production and con-sumption for the last half century. Though these regulations have created new opportunities, they have also added newburdens to the obligated parties. It is thus key for the government, the obligated parties, and related businesses to studythe impact of the policies on the SPSC. We develop a two-stage stochastic programming model, General Model (GM),which incorporates Renewable Fuel Standard 2 (RFS2), Tax Credits, Tariffs, and Blend Wall (BW) to study the policyimpact on the SPSC using cellulosic ethanol. The model, as any other general model available in the literature, makesit highly impractical to study the policy impact due to the model’s computational complexity. We use the GM to derivea Lean Model (LM) to study the impact by running computational experiments more efficiently and consequently byarriving at robust managerial insights much faster. We present a case study of the policy impact on the SPSC in theState of Nebraska using the LM in the accompanying part II (Ghahremanlou and Kubiak 2020).


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