Comparing the Behavior of Homogeneous vs. Fluid Filled Solid Headforms Under Blunt Impact Loading Conditions

2013 ◽  
Author(s):  
Veera Selvan ◽  
Virginia Halls ◽  
James Zheng ◽  
Namas Chandra
Keyword(s):  
Single Point ◽  
Head Injuries ◽  
Target Surface ◽  
Loading Conditions ◽  
Acceleration Field ◽  
Head Injury Criterion ◽  
Impact Location ◽  
Blunt Impact ◽  
Blunt Loading ◽  
The Impact

A single point acceleration measurement at the center of gravity (C.G) of the rigid headform has been typically used to assess the head injuries under the blunt loading conditions. The head protective equipment (e.g. Helmets) used in sports, vehicles and defense fields are developed and tested based on this single point acceleration. This raises two critical questions; 1) can a homogeneous rigid headform represent the heterogeneous skull-brain complex; 2) If not, which is the critical point of measurement in the compliant headform. To answer these questions, compliant (acrylic gel complex) and rigid (aluminum body) head surrogates with an identical mass are subjected to similar blunt loading conditions. Target surfaces of different stiffness and an impact velocity of 1 m/s are employed to evaluate the critical difference in the head surrogates. Acceleration (C.G) and shell strain (impact location) in the compliant surrogate and acceleration (C.G) and the impact force in the rigid surrogate are experimentally measured. Experimental and computational studies illustrate that the acceleration field in the gel-filled case varies from coup to counter-coup region; however, the acceleration field in the rigid headform is uniform. The variation in the acceleration field is influenced by the shell deformation that in turn depends on the stiffness of the target surface. In deformable target surfaces, the acceleration and head injury criterion (HIC) values are higher in the compliant surrogate than the rigid surrogate; the effect is reversed for rigid target surfaces.

scholarly journals EXPERIMENTAL EVALUATION OF THE IMPACTABSORPTION PROPERTIES OF RUBBER TILES FOR THE PLAYGROUND

2004 ◽  
Vol 16 (05) ◽  
pp. 244-250 ◽  
Author(s):  
LI-TUNG CHANG ◽  
KUEN-HORNG TSAI ◽  
JIN-SHAN SHIAU
Keyword(s):  
Head Injury ◽  
Head Injuries ◽  
Peak Acceleration ◽  
Critical Height ◽  
Shock Absorption ◽  
Absorption Properties ◽  
Head Injury Criterion ◽  
The Impact ◽  
Impact Absorption ◽  
Base Structure

Rubber tiles are popular in playgrounds as protective surfacing to reduce the incidence of head injuries caused by children falling from equipment. However, Taiwan has not yet established a test code for assessment of the shock-absorption properties of such surfacing. For this study, an experimental model was established to evaluate the behavior of various rubber tiles. A hemispherical headform was dropped from a set height to strike the center of the specimen tile. The peak acceleration and Head Injury Criterion (HIC) were measured to assess the impact absorption of and critical height for a given rubber tile. The results show that utilization of the HIC index provides a more conservative assessment of the shock absorption and, ultimately, protection from head injuries than peak acceleration. The maximum critical heights of the rubber tiles used in this study for tile thicknesses of 45, 60 and 80 mm were 1.6, 2.0 and 2.2 m, respectively. Two-part rubber tiles with a base structure consisting of a box-like core offer superior protection from head injuries relative to analogous cylindrical, square pillar and solid structures. The maximum differences in peakacceleration and HIC values comparing the box-like core and solid structures at a thickness of 45 mm were 21% and 44%, respectively. The results of this study suggest a minimum of rubber thickness of 60 mm, based on probable maximum fall heights of more than 1.6 m. Moreover, incorporation of an appropriate cushioning structure in the base of the rubber tile could further improve protection.

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 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 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 Numerical Investigation on the Ultimate Strength of Box Beams with Impact Damage

2020 ◽  
Author(s):  
Wei Xu ◽  
C. Guedes Soares
Keyword(s):  
Residual Stress ◽  
Ultimate Strength ◽  
Impact Damage ◽  
Ship Hulls ◽  
Four Point Bending ◽  
Impact Location ◽  
Box Beam ◽  
Box Beams ◽  
Fracture Damage ◽  
The Impact

AbstractThe objective of this paper is to study the residual ultimate strength of box beams with impact-induced damage, as a model of what may occur in ship hulls. The bottom and side plates of ship hulls can suffer denting or fracture damage due to grounding, collision and other contacts during the ship’s service life and these impact-induced damages could result in considerable strength degradation. Box beams are firstly subjected to impact loading and then four-point bending loading is imposed on the damaged structures to assess the residual strength using ANSYS/LS_DYNA. The ultimate moment and collapse modes are discussed considering the effect of impact location. The impact-induced deformation is introduced in the four-point bending simulation, and the impact-induced stress is included or not to determine the effect of residual stress and distortion after impact. It is shown that impact location has significant influence on the residual ultimate bending moment of the damaged box beam providing that the impact energy is kept constant. The collapse modes also change when the impactor strikes on different locations. Damaged hard corner and inclined neutral axes might explain the reduction of ultimate strength and diverse collapse modes. The residual stress in the box beam after impact may increase or decrease the ultimate strength depending on impact location.

scholarly journals Electric Vehicles in Jordan: Challenges and Limitations

2021 ◽  
Vol 13 (6) ◽  
pp. 3199
Author(s):  
Laith Shalalfeh ◽  
Ashraf AlShalalfeh ◽  
Khaled Alkaradsheh ◽  
Mahmoud Alhamarneh ◽  
Ahmad Bashaireh
Keyword(s):  
Electric Vehicles ◽  
Distribution System ◽  
Distribution Systems ◽  
Environmental Benefits ◽  
System Stability ◽  
Loading Conditions ◽  
Stability Margins ◽  
High Penetration ◽  
Node Distribution ◽  
The Impact

An increasing number of electric vehicles (EVs) are replacing gasoline vehicles in the automobile market due to the economic and environmental benefits. The high penetration of EVs is one of the main challenges in the future smart grid. As a result of EV charging, an excessive overloading is expected in different elements of the power system, especially at the distribution level. In this paper, we evaluate the impact of EVs on the distribution system under three loading conditions (light, intermediate, and full). For each case, we estimate the maximum number of EVs that can be charged simultaneously before reaching different system limitations, including the undervoltage, overcurrent, and transformer capacity limit. Finally, we use the 19-node distribution system to study these limitations under different loading conditions. The 19-node system is one of the typical distribution systems in Jordan. Our work estimates the upper limit of the possible EV penetration before reaching the system stability margins.

scholarly journals OP0277-PARE METABERN, THE EUROPEAN REFERENCE NETWORK FOR RARE HEREDITARY DISEASES: STRUCTURE, OBJECTIVES, METABOLIC RMDS AND THE ROLES OF EUROPEAN PATIENT ADVOCACY GROUPS (EPAGS)

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 168.2-168
Author(s):  
L. Wagner ◽  
S. Sestini ◽  
C. Brown ◽  
A. Finglas ◽  
R. Francisco ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Health Care ◽  
Social Science ◽  
Metabolic Pathways ◽  
Metabolic Disorders ◽  
Clinical Care ◽  
Single Point ◽  
Link Type ◽  
The Impact

Background:Inborn metabolic disorders (IMDs) currently encompass more than 1,500 diseases with new ones still to be identified1. Each of them is characterised by a genetic defect affecting a metabolic pathway. Only few of them have curative treatments, that target the respective metabolic pathway. Commonly, treatment examples include diet, substrate reduction therapies, enzyme replacement therapies, gene therapy and biologicals, enabling IMD-patient now to survive to adulthood. About 30 % of all IMDs involve the musculoskeletal system and are here referred to as rare metabolic RMDs. Generally, IMDs are very heterogenous with respect to symptoms and severity, often being systemic and affecting more children than adults. Thus, challenges include certified advanced training of adult metabolic experts, standardised transition plans, social support and development of therapies for diseases that do not have any cure yet.Objectives:Introduction of MetabERN, its structure and objectives, highlighting on the unique features and challenges of metabolic RMDs and describing the involvement of patient representation in MetabERN.Methods:MetabERN is stratified in 7 subnetworks (SNW) according to the respective metabolic pathways and 9 work packages (WP), including administration, dissemination, guidelines, virtual counselling framework, research/clinical trials, continuity of care, education and patient involvement. The patient board involves a steering committee and single point of contacts for each subnetwork and work package, respectively2. Projects include identifying the need of implementing social science to assess the psycho-socio-economic burden of IMDs, webinars on IMDs and their transition as well as surveys on the impact of COVID-193 on IMD-patients and health care providers (HCPs), social assistance for IMD-patients and analysing the transition landscape within Europe.Results:The MetabERN structure enables bundling of expertise, capacity building and knowledge transfer for faster diagnosis and better health care. Rare metabolic RMDs are present in all SNWs that require unique treatments according to their metabolic pathways. Implementation of social science to assess the psycho-socio-economic burden of IMDs is still underused. Involvement of patient representatives is essential for a holistic healthcare not only focusing on clinical care, but also on the quality of life for IMD-patients. Surveys identified unmet needs of patient care, patients having little information on national support systems and structural deficits of healthcare systems to ensure HCP can provide adequate clinical care during transition phases. These results are collected by MetabERN and forwarded to the Directorate-General for Health and Food Safety (DG SANTE) of the European Commission (EC) to be addressed further.Conclusion:MetabERN offers an infrastructure of virtual healthcare for patients with IMDs. Thus, in collaboration with ERN ReCONNET, MetabERN can assist in identifying rare metabolic disorders of RMDs to shorten the odyssey of diagnosis and advise on their respective therapies. On the other hand, MetabERN can benefit from EULAR’s longstanding experience regarding issues affecting the quality of life, all RMD patients are facing, such as pain, stiffness, fatigue, rehabilitation, maintaining work and disability claims.References:[1]IEMbase - Inborn Errors of Metabolism Knowledgebase http://www.iembase.org/ (accessed Jan 29, 2021).[2]MetabERN: European Refence Network for Hereditary Metabolic Disorders https://metab.ern-net.eu/ (accessed Jan 29, 2021).[3]Lampe, C.; Dionisi-Vici, C.; Bellettato, C. M.; Paneghetti, L.; van Lingen, C.; Bond, S.; Brown, C.; Finglas, A.; Francisco, R.; Sestini, S.; Heard, J. M.; Scarpa, M.; MetabERN collaboration group. The Impact of COVID-19 on Rare Metabolic Patients and Healthcare Providers: Results from Two MetabERN Surveys. Orphanet J. Rare Dis.2020, 15 (1), 341. https://doi.org/10.1186/s13023-020-01619-x.Acknowledgements:The authors thank the MetabERN collaboration group, the single point of contacts (SPOC) of the MetabERN patient board and the Transition Project Working Group (TPWG)Disclosure of Interests:None declared

The effects of corporate brand symbolism on consumer satisfaction and loyalty

2016 ◽  
Vol 28 (3) ◽  
pp. 481-498 ◽  
Author(s):  
Tatiana Anisimova
Keyword(s):  
Social Life ◽  
Consumer Satisfaction ◽  
Single Point ◽  
Social Aspects ◽  
Consumer Loyalty ◽  
Cross Sectional ◽  
Corporate Brand ◽  
Content Type ◽  
Strategic Role ◽  
The Impact

Purpose – The purpose of this paper is to test the effects of corporate brand symbolism on consumer satisfaction and loyalty on a sample of Australian automobile consumers. Design/methodology/approach – Survey research was employed to test the study hypotheses. The regression analysis was used to evaluate the relationships between an independent variable (corporate brand symbolism) and dependent variables (consumer satisfaction and loyalty). Findings – Support was found for all hypotheses formulated in this study. Regression results reveal consistent favourable and significant effects of corporate brand symbolism on both consumer satisfaction and loyalty. Research limitations/implications – Although this paper makes contributions in international marketing, the cross-sectional nature of the data collection method limits the information gained to the single point in time. This research studied the impact of corporate brand symbolism on consumers of one original equipment manufacturers (OEM). Having a larger number of participating car manufacturers/OEMs would have provided a wider insight. However, time and resources limitation did not allow to study a larger sample. In the future, practitioners are recommended to further understand the relationship between self and social aspects of brand symbolism in order to formulate more targeted communication strategies. Practical implications – The findings of this study point to the strategic role of the brand in generating both satisfaction and loyalty. In the light of increasing advertising costs and decreasing consumer loyalty, strengthening corporate brand symbolism makes a lot of economic sense. The findings suggest that managers need to take into account consumer need for identity expression and consider this in their branding strategies. Social implications – Humans are social beings by nature. However, international brand research has paid relatively little attention to how products are used by consumers in everyday life, including their social life. Consumer behaviours increasingly depend on social meanings they imbue brands with beyond products’ functional utility. It is argued the focus of symbolic consumption needs to be broadened and integrated more with social science concepts. Originality/value – This study captures a construct of corporate brand symbolism by including self and social aspects of symbolism. The current study also comprehensively measures consumer loyalty, including cognitive, affective and behavioural types of loyalty.

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