scholarly journals Fuel Tank Integrity Research: Fuel Tank Analyses and Test Plans

2013 ◽  
Author(s):  
Karina Jacobsen ◽  
Patricia Llana ◽  
Michael Carolan ◽  
Laura Sullivan
Keyword(s):  
Dynamic Loading ◽  
Deformation Behavior ◽  
Impact Testing ◽  
Fuel Tank ◽  
Loading Conditions ◽  
Dynamic Impact ◽  
Research Activities ◽  
Blunt Impact ◽  
Fuel Tanks ◽  
The Impact

The Federal Railroad Administration’s Office of Research and Development is conducting research into fuel tank crashworthiness. Fuel tank research is being performed to determine strategies for increasing the fuel tank impact resistance to mitigate the threat of a post-collision or post-derailment fire. In accidents, fuel tanks are subjected to dynamic loading, often including a blunt or raking impact from various components of the rolling stock or trackbed. Current design practice requires that fuel tanks have minimum properties adequate to sustain a prescribed set of static load conditions. Current research is intended to increase understanding of the impact response of fuel tanks under dynamic loading. Utilizing an approach that has been effective in increasing the structural crashworthiness of railcars, improved strategies can be developed that will address the types of loading conditions which have been observed to occur in a collision or derailment event. U.S. rail accident surveys reveal the types of threats fuel tanks are exposed to during collision, derailments and other events. These include both blunt impacts and raking impacts to any exposed side of the tank. This research focuses on evaluating dynamic impact conditions for fuel tanks and investigating how fuel tank design features affect the collision performance of the tank. Research activities will include analytical modeling of fuel tanks under dynamic loading conditions, dynamic impact testing of fuel tank articles, and recommendations for improved fuel tank protection strategies. This paper describes detailed finite element analyses that have been developed to estimate the behavior of three different fuel tanks under a blunt impact. These analyses are being used to understand the deformation behavior of different tanks and prepare for planned testing of two of these tanks. Observations are made on the influence of stiffeners, baffles, and other design details relative to the distance from impact. This paper subsequently describes the preliminary test plans for the first set of tests on conventional passenger locomotive fuel tanks. The first set of tests is designed to measure the deformation behavior of the fuel tanks with a blunt impact of the bottom face of the tanks. The test articles are fuel tanks from two retired EMD F-40 locomotives. A blunt impact will be conducted by securing the test articles to a crash wall and impacting them with an indenter extending from a test cart. This set of tests is targeted for late summer 2013 at the Transportation Technology Center (TTC) in Pueblo, Colorado. Both blunt and raking impact conditions will be evaluated in future research. Tests are also being planned for DMU fuel tanks under dynamic loads.

scholarly journals Test Requirements of Locomotive Fuel Tank Blunt Impact Tests

2013 ◽  
Author(s):  
Karina Jacobsen ◽  
Michael Carolan ◽  
Patricia Llana
Keyword(s):  
Dynamic Loading ◽  
Lessons Learned ◽  
Fuel Tank ◽  
Bottom Surface ◽  
Loading Conditions ◽  
Impact Tests ◽  
Blunt Impact ◽  
Fuel Tanks ◽  
Test Requirements ◽  
The Impact

The Federal Railroad Administration’s Office of Research and Development is conducting research into passenger locomotive fuel tank crashworthiness. A series of impact tests are planned to measure fuel tank deformation under two types of dynamic loading conditions. This paper describes the test requirements for the preliminary tests in this series — a blunt impact of conventional locomotive fuel tanks. Current design practice requires that Tier 1 locomotive fuel tanks have minimum properties adequate to sustain a prescribed set of static load conditions [1]. In accidents, fuel tanks are subjected to dynamic loading, often including a blunt or raking impact from various components of the rolling stock or trackbed. Current research is intended to increase understanding of the impact response of fuel tanks under dynamic loading. Utilizing an approach that has been effective in increasing the structural crashworthiness of passenger railcars, improved strategies can be developed that will address the types of loading conditions which have been observed to occur in a collision or derailment event. The improvement strategies developed by this research program can then be applied to alternative fuel tank designs, such as diesel multiple unit (DMU) tanks. This paper describes test requirements for conducting two preliminary tests. These tests are referred to as preliminary because they will be used to evaluate the loading setup and instrumentation planned for the larger series of tests. These preliminary tests will evaluate a blunt impact on the bottom surface of two conventional passenger locomotive fuel tanks. The test articles chosen for the preliminary tests are fuel tanks removed from two retired EMD F-40 locomotives. While these fuel tanks do not reflect the current state of locomotive fuel tank manufacturing or design, they are suitable for means of these tests. Each fuel tank will be mounted to a crash wall and impacted on its bottom face by an impact cart with a rigid impactor at a prescribed velocity. The first set of tests is designed to measure the deformation behavior of the fuel tanks. These tests are planned to result in puncture of the bottom surface of each fuel tank. The preliminary tests are targeted for October 2013 at the Transportation Technology Center (TTC) in Pueblo, Colorado. Following this first series of impact tests, a second set of dynamic impact tests is planned to be conducted. This second set will include both blunt and raking impact conditions on conventional fuel tanks, DMU fuel tanks and fuel tanks incorporating improved strategies for impact protection. Lessons learned during the preliminary two tests will be applied during the second set of tests to improve the performance of those tests. Fuel tank research is being performed to determine strategies for increasing the fuel tank impact resistance to mitigate the threat of a post-collision or post-derailment fire.

scholarly journals Conventional Fuel Tank Blunt Impact Tests: Test and Analysis Results

2014 ◽  
Author(s):  
Karina Jacobsen ◽  
Michael Carolan ◽  
Benjamin Perlman
Keyword(s):  
Finite Element ◽  
Dynamic Loading ◽  
Fuel Tank ◽  
Test Tank ◽  
Impact Tests ◽  
Impact Location ◽  
Blunt Impact ◽  
Fuel Tanks ◽  
Post Test ◽  
The Impact

The Federal Railroad Administration’s Office of Research and Development is conducting research into fuel tank crashworthiness. A series of impact tests are planned to measure fuel tank deformation under two types of dynamic loading conditions — blunt and raking impacts. This paper describes the results of the first set of blunt impact tests for two retired EMD F-40 locomotive fuel tanks, Tank 232 and Tank 202. On October 8, 2013 and October 9, 2013, the FRA performed impact tests on two conventional passenger locomotive fuel tanks at the Transportation Technology Center (TTC) in Pueblo, Colorado. Each fuel tank was emptied of fluid and mounted on a crash wall with the bottom surface exposed. A rail cart modified with a “rigid” indenter was released to impact the center of the bottom of each fuel tank at about 6 mph. A center-impact on Tank 232 was chosen to impact between two baffles. A center-impact on Tank 202 was chosen to impact on a baffle. In the first test, Tank 232 was impacted by the indenter at 4.5 mph. The maximum residual indentation on the bottom of the tank measured approximately 5 inches. The tank deformed across the middle longitudinal span of the tank forming a diamond-shaped indention. In the second test, Tank 202 was impacted by the indenter at 6.2 mph. The maximum residual indentation on the bottom of the tank measured approximately 1.5 inches. The bottom of the tank deformed with an “X” shape spanning out from the location of square indenter at the center of the tank. Post-test autopsies revealed the deformation of the interior structures, i.e. baffles and attachments. There was no damage to the baffles in Tank 232. Deformation to the interior structure of Tank 202 was limited to the baffle directly beneath the impact location, which folded in the area near the impact location. Material coupons were cut and tensile testing performed to determine the properties of the materials used in each tank. Prior to the test, computer models were developed from measurements taken on the test articles. Material properties were estimated based on Brinell hardness measurements. Computer analyses were conducted to determine the conditions for the test, i.e. instrumentation, location of impact, target impact speeds and to predict the deformation behavior of the tank. Post-test, the resulting stress-strain relationships for the bottom sheets and baffles of both tanks were used to update the finite element models of the two tanks. The models were also updated to reflect the actual geometry of the tanks as confirmed by measurements of the tank interiors. The results of the finite element (FE) models run at the test conditions with the updated tank details are compared with the results from the test itself. Specifically, the deformation progression and the residual dent depth are compared between the tests and the models. In accidents, fuel tanks are subjected to dynamic loading, often including a blunt or raking impact from various components of the rolling stock or trackbed. Current design practice requires that fuel tanks have minimum properties adequate to sustain a prescribed set of static load conditions. Current research is intended to increase understanding of the impact response of fuel tanks under dynamic loading.

scholarly journals Results of a Diesel Multiple Unit Fuel Tank Blunt Impact Test

2017 ◽  
Author(s):  
Karina Jacobsen ◽  
Michael Carolan
Keyword(s):  
Research Program ◽  
Impact Test ◽  
Fuel Tank ◽  
Test Material ◽  
Fe Model ◽  
Puncture Resistance ◽  
Blunt Impact ◽  
Fuel Tanks ◽  
Post Test ◽  
The Impact

The Federal Railroad Administration’s Office of Research and Development is conducting research into passenger locomotive fuel tank crashworthiness. A series of impact tests is being conducted to measure fuel tank deformation under two types of dynamic loading conditions — blunt and raking impacts. The results of this research program assist in development of appropriate standards for puncture resistance requirements to be applied to alternatively-designed fuel tanks, such as on diesel multiple unit (DMU) passenger rail equipment. This paper describes the results of the first blunt impact test performed on a DMU fuel tank. On June 28, 2016, FRA performed a dynamic impact test of a fuel tank from a DMU rail vehicle. The test was performed at the Transportation Technology Center (TTC) in Pueblo, Colorado. An impact vehicle weighing approximately 14,000 pounds and equipped with a 12-inch by 12-inch impactor head struck the bottom surface of a DMU fuel tank mounted vertically on an impact wall. The impact occurred on the bottom of the fuel tank at a location centered on two baffles within the fuel tank. The target impact speed was 11.5 mph, and the measured impact speed 11.1 mph. The test resulted in a maximum indentation of approximately 8 inches, the bottom of the tank bending away from the wall, and buckling of several internal baffles. Following the test, the tank was cut open to inspect the damage to the internal structure. This revealed that the buckling behavior of the baffles was isolated to the baffles immediately adjacent the impact location, each one buckling as the tank deformed inward. Prior to the test, finite element analysis (FEA) was used to predict the behavior of the tank during the test. The FE model of the tank required material properties to be defined in order to capture plastic deformation. The combination of metal plasticity, ductile failure, and element removal would permit the model to simulate puncture for this tank at sufficiently-high impact speeds. The pre-test FE model results compared very favorably with the test measurements, and both the pre-test model and the test resulted in similar modes of deformation to the DMU fuel tank. Following the test, material coupons were cut from undamaged areas of the fuel tank and subjected to tensile testing. The post-test FE model was updated with the material behaviors from the post-test material testing. This test is part of a research program investigating puncture resistance of passenger locomotive fuel tanks. The objective of this research program is to establish the baseline puncture resistance of current locomotive fuel tanks under dynamic impact conditions and to develop performance requirements for an appropriate level of puncture resistance in alternative fuel tank designs, such as DMU fuel tanks. Future tests are planned within this research program. The lessons learned during the series of tests support finite element (FE) modeling of impact conditions beyond what was tested. Additional tests investigating the puncture resistance of fuel tanks during sideswipe or raking collisions are also planned.

Raking Impact of a Diesel Multiple Unit Fuel Tank: Tests and Anaylsis

2020 ◽  
Author(s):  
Karina Jacobsen ◽  
Michael Carolan
Keyword(s):  
Finite Element Analysis ◽  
Static Load ◽  
Fuel Tank ◽  
Dynamic Impact ◽  
Element Analysis ◽  
Static Tests ◽  
Puncture Resistance ◽  
Blunt Impact ◽  
Fuel Tanks ◽  
Multiple Unit

Abstract The Federal Railroad Administration (FRA) sponsors research on safety topics to address and to improve safety regulations and standards. This paper focuses on the latest research and testing conducted to evaluate passenger locomotive fuel tank integrity. Fuel tank integrity regulations, in the form of a series of static load conditions, currently exist to set a minimum level of protection against an impact to the fuel tank that might puncture the tank and cause the release of diesel fuel. The current research program involves a series of dynamic impact tests and quasi-static tests that measures the forces required to deform a fuel tank and investigate the types of loading conditions experienced by fuel tanks. The objective of the testing program is to establish the baseline puncture resistance of current locomotive fuel tanks under dynamic impact conditions and to develop performance requirements for an appropriate level of puncture resistance in alternative fuel tank designs, such as Diesel Multiple Unit (DMU) fuel tanks. The tests are divided into two loading scenarios identified from accidents: blunt impact and raking impact. The blunt impact scenario in the form of a full-scale dynamic impact test, have been completed on both conventional passenger locomotive fuel tanks and a DMU fuel tank. DMU fuel tank quasi-static tests, conducted in December 2018 and November 2019, are designed to simulate a raking impact scenario of a fuel tank. The Transportation Technology Center Inc. (TTCI), with support from the Volpe Center designed a test setup using a fuel tank mounted to a boxcar placed within the “squeeze frame”. An indenter, shaped like a broken rail, is fixed to the ground and the fuel tank is slowly pushed into the indenter using a series of hydraulic rams. Load cells and string potentiometers are used to measure the force/displacement. Cameras capture the deformation profile of the fuel tank. The Volpe Center develops and performs finite element analysis to evaluate the loading scenario prior to testing. The results of pre-test analyses for the raking impact tests are presented to highlight the critical position on the fuel tank to be impacted. The analysis gives an estimate of the force required to puncture the fuel tank as well as the resultant tear of the fuel tank. Additionally, finite element analysis may be used to evaluate the effect of the fuel on the fuel tank integrity. These results highlight the detailed differences of quasi-static versus dynamic loading of fuel tanks, which supports defining tradeoffs between specifying static load requirements versus scenario-defined performance based standards.

Updated Fuel Tank Puncture Survey: 1995-2020

2021 ◽  
Author(s):  
Karina Jacobsen
Keyword(s):  
Fuel Tank ◽  
Technical Data ◽  
Passenger Rail ◽  
Blunt Impact ◽  
Field Investigations ◽  
Fuel Tanks ◽  
Serious Injury ◽  
Conducting Research ◽  
Railroad System ◽  
General Operation

Abstract The Federal Railroad Administration’s Office of Research, Development and Technology has been conducting research into passenger fuel tank crashworthiness. The occurrence of a fuel tank puncture during passenger rail collisions and derailments increases the potential of serious injury and fatality for crew and passengers due to the possibility of fire. The purpose of the FRA research is to help support regulatory and standard development with technical data. In the last decade, the research has focused on understanding how fuel tanks are punctured during an impact and how various tank designs respond to common types of loading in collisions, derailments and general operation. Throughout the research, surveys have been conducted to determine the most likely scenarios that are causing fuel tank punctures. A previous FRA survey found that fuel tank punctures occur under two types of loading conditions: a blunt impact or a raking impact. A limited number of accident/incidents were evaluated in this survey. These incidents showed that fuel tanks are punctured on any side that is not protected or shielded. The purpose of this paper is to report on a recently conducted fuel tank puncture survey updated to include the last decade. This paper identifies and describes accidents and incidents that led to breached fuel tanks in freight and passenger trains traveling on the general railroad system in the U.S. between 2008 and 2020. The results include data from the FRA’s Railroad Accident/Incident Reporting System (RAIRS), queried from 1995 to 2020. This data include the number of recorded accidents/incidents and other trends like fuel spillage, operating authority and cause of accident/incident. RAIRS data showed accidents/incidents with fuel tank puncture ranging from 10 to 55 accidents/incidents per year. Additionally, more detailed results are shared from field investigations recently conducted by the FRA or Volpe Center. These more detailed investigations provide additional insight into the types of loading that may lead to a fuel tank puncture. This survey supplements the RAIRS data with more detailed information from field investigations. The paper finally discusses the conditions that lead to fire and the associated hazards.

Study Regarding the Influence of the Fuel Tank Constructive Characteristics on Slosh-Noise Effect

2016 ◽  
Vol 834 ◽  
pp. 22-27 ◽  
Author(s):  
Oana Maria Manta Balas ◽  
Radu Balas ◽  
Cristian Vasile Doicin
Keyword(s):  
The Body ◽  
Fuel Tank ◽  
Noise Effect ◽  
Great Achievement ◽  
Fuel Tanks ◽  
Entire Vehicle ◽  
Body In White ◽  
Innovative Potential ◽  
The Impact ◽  
The Waves

The aim of this article is to highlight the impact of the fuel movements inside the plastic fuel tank (waves) for the client perception of noise. Today there isn’t a clear methodology regarding the reproducing the fuel waves, but there are different approaches to be taken into account and also there is an innovative potential. Due to the fast technological progress the body in white and not only, the entire vehicle became lighter and lighted. A consequence of this great achievement is that the client can hear easier the sound produced by different components of the car. The plastic fuel tank can be considered such a component. The authors have done a deep analysis of present automotive fuel tanks and propose solutions for breaking the waves produced inside fuel tanks, so as to reduce the slosh noise effect. The studies will be continued during the doctoral approach of the first author.

Behavior Evaluation of Deformation, Damage and Fracture of Biological Soft Tissue by Using Indentation Test

2016 ◽  
Author(s):  
Atsushi Sakuma ◽  
Katsuya Igarashi
Keyword(s):  
Stress Response ◽  
Soft Tissue ◽  
Deformation Behavior ◽  
Reaction Force ◽  
Indentation Test ◽  
Impact Testing ◽  
Ball Impact ◽  
Damage And Fracture ◽  
The Impact ◽  
Biological Soft Tissue

In this study, two types of indentation tests were used for the observation of deformation behavior of biological soft tissue, because indentation testing is an easy method to manage observation and control of the condition of complex tissue specimens. First, a fundamental indentation test was used to evaluate quasi-static deformation behavior of soft tissue. In the evaluation of the quasi-static behavior, elasticity, damage, and fracture of the tissue were analyzed from the profile of reaction force during the indentation. Ball-impact testing with subsonic indentation velocity was used for the evaluation of dynamic behaviors of soft tissue. In the impact test, the viscoelastic characteristics of specimens were evaluated by analyzing stress response, using extended Hertzian contact theory and wave equations, at the moment when a simple ball bullet shot from an airsoft gun strikes the specimen. In the experimental results of the test, an obvious relationship between quasi-static and impact responses of the specimen were observed subjectively. The results are evaluated to analyze the damage and the fracture of the soft tissue for the objective formulation of tissue mechanics. The plateau behavior of reaction force in relation to stress response was also reviewed, in order to quantify the beginning of tissue fracture.

scholarly journals DYNAMIC IMPACT WEAR AND IMPACT RESISTANCE OF W-B-C COATINGS

2020 ◽  
Vol 27 ◽  
pp. 37-41
Author(s):  
Josef Daniel ◽  
Jan Grossman ◽  
Vilma Buršíková ◽  
Lukáš Zábranský ◽  
Pavel Souček ◽  
...  
Keyword(s):  
Impact Test ◽  
Impact Load ◽  
Protective Coatings ◽  
Impact Resistance ◽  
Impact Testing ◽  
The Novel ◽  
Test Results ◽  
Dynamic Impact ◽  
Impact Deformation ◽  
The Impact

Coated components used in industry are often exposed to repetitive dynamic impact load. The dynamic impact test is a suitable method for the study of thin protective coatings under such conditions. Aim of this paper is to describe the method of dynamic impact testing and the novel concepts of evaluation of the impact test results, such as the impact resistance and the impact deformation rate. All of the presented results were obtained by testing two W-B-C coatings with different C/W ratio. Different impact test results are discussed with respect to the coatings microstructure, the chemical and phase composition, and the mechanical properties. It is shown that coating adhesion to the HSS substrate played a crucial role in the coatings’ impact lifetime.

Deformation behavior of D-Shaped shallow tunnels under dynamic loading conditions

Structures ◽  
2021 ◽  
Vol 33 ◽  
pp. 3973-3983
Author(s):  
Rohan Ramesh Dhamne ◽  
Swapnil Mishra ◽  
Ankesh Kumar ◽  
K.S. Rao
Keyword(s):  
Dynamic Loading ◽  
Deformation Behavior ◽  
Loading Conditions ◽  
Shallow Tunnels ◽  
Dynamic Loading Conditions

Modeling the Impact Response of HDPE Fuel Tank Material

2009 ◽  
Author(s):  
Xinran Xiao ◽  
Vinayshankar Virupaksha
Keyword(s):  
Deformation Behavior ◽  
High Density Polyethylene ◽  
Method Development ◽  
Fuel Tank ◽  
Impact Response ◽  
Lateral Impact ◽  
Three Point Bending ◽  
Deformation And Fracture ◽  
Fracture Behaviors ◽  
The Impact

As a part of the effort on modeling method development for crashworthiness prediction of vehicle structures, this paper examines the impact response of a multilayer high density polyethylene (HDPE) fuel tank material. The deformation behavior of HDPE under lateral impact was investigated by flexural experiment using three-point bending, and by driven dart impact with different velocities at ambient and −40°C. The large deformation and fracture behaviors of multilayer HDPE under impact loading at different rates and temperatures were simulated using LS-DYNA®.

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