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Viewing 181 to 210 of 16139
2015-04-14
Technical Paper
2015-01-1488
Adam G. M. Cook, Moustafa El-Gindy, David Critchley
Abstract This work investigates a multi-objective optimization approach for minimizing design parameters for Front Underride Protection Devices (FUPDs). FUPDs are a structural element for heavy vehicles to improve crashworthiness and prevent underride in head-on collision with another vehicle. The developed dsFUPD F9 design for a Volvo VNL was subjected to modified ECE R93 testing with results utilized in the optimization process. The optimization function utilized varying member thickness to minimize deformation and system mass. Enhancements to the function were investigated by introducing variable materials and objectifying material cost. Alternative approaches for optimization was also needed to be explored. Metamodel-based and Direct simulation optimization strategies were compared to observe there performance and optimal designs.
2015-04-14
Technical Paper
2015-01-1477
Robert Larson, Jeffrey Croteau, Cleve Bare, John Zolock, Daniel Peterson, Jason Skiera, Jason R. Kerrigan, Mark D. Clauser
Abstract Extensive testing has been conducted to evaluate both the dynamic response of vehicle structures and occupant protection systems in rollover collisions though the use of Anthropomorphic Test Devices (ATDs). Rollover test methods that utilize a fixture to initiate the rollover event include the SAE2114 dolly, inverted drop tests, accelerating vehicle body buck on a decelerating sled, ramp-induced rollovers, and Controlled Rollover Impact System (CRIS) Tests. More recently, programmable steering controllers have been used with sedans, vans, pickup trucks, and SUVs to induce a rollover, primarily for studying the vehicle kinematics for accident reconstruction applications. The goal of this study was to create a prototypical rollover crash test for the study of vehicle dynamics and occupant injury risk where the rollover is initiated by a steering input over realistic terrain without the constraints of previously used test methods.
2015-04-14
Technical Paper
2015-01-1491
Dinesh Munjurulimana, Dhanendra Nagwanshi, Matthew Marks
Abstract Automotive OEMs, insurance agencies and regulatory bodies are continuously looking at various accident statistics and proper ways of evaluating unaccounted (as per current regulations and safety ratings) accident scenarios to improve the safety standards of cars. Small overlap and oblique impacts during which a corner of a car hits a tree or the corner of another vehicle are two such situations. Most of the vehicles that are on road scored low when tested for these impact scenarios. This paper focuses on development of energy-absorbing members, using engineering thermoplastics materials, which can be mounted on the BIW of a vehicle, as countermeasures to small overlap impact. Various design and material configurations options, including metal plastic and composite plastic structural members mounted on the BIW are evaluated through CAE studies, against small overlap/oblique impact scenarios.
2015-04-14
Technical Paper
2015-01-1492
Kazunobu Ogaki, Takayuki Kawabuchi, Satoshi Takizawa
Abstract The National Highway Traffic Safety Administration (NHTSA) has developed moving deformable barriers for vehicle crash test procedures to assess vehicle and occupant response in partial overlap vehicle crashes. For this paper, based on the NHTSA Oblique Test procedure, a mid-size sedan was tested. The intent of this research was to provide insight into possible design changes to enhance the oblique collision performance of vehicles. The test results predicted high injury risk for BrIC, chest deflection, and the lower extremities. In this particular study, reducing lower extremity injuries has been focused on. Traditionally, lower extremity injuries have been reduced by limiting the intrusion of the lower region of the cabin's toe-board. In this study, it is assumed that increasing the energy absorbed within the engine compartment is more efficient than reinforcing the passenger compartment as a method to reduce lower extremity injuries.
2015-04-14
Technical Paper
2015-01-1414
Jitendra Shah, Mohamed Benmimoun
In the framework of large scale project interactIVe co-funded by the European Commission Ford has developed an active safety system for the supported and autonomous avoidance of rear end collisions by intervention of braking and steering systems. This paper focuses on the assessment of threat perceived by drivers in collision avoidance situation. The decision making related to the initiation of the interventions by driver is crucial to understand how much threat is the driver can hold. The study has helped to understand how driver feels a threat arising from environment. It is a step towards autonomous driving where the system interventions have to be initiated as early as possible in order to avoid the collision and avoid unstable vehicle dynamics situations. In parallel the reaction has to be delayed long enough until it is likely that the driver will no longer intervene or respectively he is no longer able to intervene. For this reason an experiment is conducted with 26 subjects.
2015-04-14
Technical Paper
2015-01-1705
Miguel Hurtado, Amine Taleb-Bendiab, Julien Moizard, Patrice M. Reilhac, Heinz Mattern
Abstract Current market trend indicates an increased interest in replacing mirrors by camera monitor systems (CMS) to reduce CO2 emissions and to improve visibility of surrounding environment to the driver. A CMS is an advanced system composed of an electronic imager, a display, and an intelligent electronic control unit intended to provide at least the same level of functionality of legally prescribed mirrors. A CMS must also take into consideration several factors in the designed system to satisfy an overall system magnification and system resolution. Some factors pertain to the camera, and display inside the cockpit, but some other are related to the physical constraints of the human operator, i.e. visual acuity, height, etc. In this paper, we demonstrate that there exists a fundamental nonlinear equation for a given CMS encompassing factors that influence the performance of the system.
2015-04-14
Technical Paper
2015-01-1703
John D. Bullough
Abstract Assessing the safety impacts of vehicle forward lighting is a challenge because crash data do not always contain details necessary to ascertain the role, if any, of lighting in crashes. The present paper describes several approaches to evaluating the safety impacts of lighting using naturalistic driving data. Driving behavioral data and descriptive narratives of crashes and near-miss incidents might provide new opportunities to understand how forward lighting improves traffic safety.
2015-04-14
Technical Paper
2015-01-1700
John D. Bullough
Abstract Warning lights and beacons on service vehicles such as maintenance trucks, tow trucks, utility service vehicles and delivery vehicles are an important line of defense for the workers who operate them. These flashing lights can also contribute to visual chaos making it difficult to navigate through a work zone location. Research on the flashing configuration and spatial and temporal coordination of warning lights that could adapt to ambient conditions and situations is described, leading to recommendations for preliminary performance specifications
2015-04-14
Journal Article
2015-01-0449
Libo Cao, Kai Zhang, Xin Lv, Lingbo Yan
Abstract The public Hybrid III family finite element models have been used in simulation of automotive safety research widely. The validity of an ATD finite element model is largely dependent on the accuracy of model structure and accurate material property parameters especially for the soft material. For Hybrid III 50th percentile male dummy model, the femur load is a vital parameter for evaluating the injury risks of lower limbs, so the importance of accuracy of knee subcomponent model is obvious. The objective of this work was to evaluate the accuracy of knee subcomponent model and improve the validity of it. Comparisons between knee physical model and knee finite element model were conducted for both structure and property of material. The inaccuracy of structure and the material model of the published model were observed.
2015-04-14
Journal Article
2015-01-0567
Kenji Takada, Kentaro Sato, Ninshu Ma
Abstract In order to reduce automobile body weight and improve crashworthiness, the use of high-strength steels has increased greatly in recent years. An optimal combination of both crash safety performance and lightweight structure has been a major challenge in automobile body engineering. In this study, the Cockcroft-Latham fracture criterion was applied to predict the fracture of high-strength steels. Marciniak-type biaxial stretching tests for high-strength steels were performed to measure the material constant of the Cockcroft-Latham fracture criterion. Furthermore, in order to improve the simulation accuracy, local anisotropic parameters based on the plastic strain (strain dependent model of anisotropy) were measured using the digital image grid method and were incorporated into Hill's anisotropic yield condition by the authors. In order to confirm the validity of the Cockcroft-Latham fracture criterion, uniaxial tensile tests were performed.
2015-04-14
Technical Paper
2015-01-1330
Yoshiyuki Tosa, Hiroyuki Mae
Abstract The objective of this study is to accurately predict the dynamic strain on the windshield caused by the deployment of the airbag in a short term without vehicle tests. The following assumption is made as to the dynamic pressure distribution on the windshield: The deployment of the airbag is fast enough to ignore spatial difference in the patterns of the pressure time histories. Given this assumption, significant parameters of the dynamic pressure distribution are as follows: 1) the distribution of the maximum pressure during contact between the airbag and the windshield, and 2) the characteristic of the force time histories applied to the windshield by the deploying airbag. In this study, the prediction method consists of a simplified airbag deployment test and an FE simulation. The simple deployment test was conducted to measure the peak pressure distribution between the airbag and a flat panel simulating the windshield.
2015-04-14
Journal Article
2015-01-0740
John Patalak, Thomas Gideon, John W. Melvin, Mike Rains
Abstract Throughout the first decade of the twenty first century, large improvements in occupant safety have been made in NASCAR®'s (National Association for Stock Car Auto Racing, Inc) race series. Enhancements to the occupant restraint system include the development and implementation of head and neck restraints, minimum performance requirements for belts and seats and the introduction of energy absorbing foam are a few highlights, among others. This paper discusses nineteen sled tests used to analyze hypothesized improvements to restraint system mounting geometry. The testing matrix included three sled acceleration profiles, three impact orientations, two Anthropomorphic Test Device (ATD) sizes as well as the restraint system design variables.
2015-04-14
Journal Article
2015-01-1386
Devin SJ Caplow-Munro, Helen Loeb, Venk Kandadai, Flaura Winston
Abstract Inadequate situation awareness and response are increasingly recognized as prevalent critical errors that lead to young driver crashes. To identify and assess key indicators of young driver performance (including situation awareness), we previously developed and validated a Simulated Driving Assessment (SDA) in which drivers are safely and reproducibly exposed to a set of common and potentially serious crash scenarios. Many of the standardized safety measures can be calculated in near real-time from simulator variables. Assessment of situation awareness, however, largely relies on time-consuming data reduction and video coding. Therefore, the objective of this research was to develop a near real-time automated method for analyzing general direction and location of driver's gaze in order to assess situation awareness.
2015-04-14
Journal Article
2015-01-1408
Kristofer D. Kusano, Hampton C. Gabler
Abstract Intersection crashes are a frequent and dangerous crash mode in the U.S. Emerging Intersection Advanced Driver Assistance Systems (I-ADAS) aim to assist the driver to mitigate the consequences of vehicle-to-vehicle crashes at intersections. In support of the design and evaluation of such intersection assistance systems, characterization of the road, environment, and drivers associated with intersection crashes is necessary. The objective of this study was to characterize intersection crashes using nationally representative crash databases that contained all severity, serious injury, and fatal crashes. This study utilized four national crash databases: the National Automotive Sampling System, General Estimates System (NASS/GES); the NASS Crashworthiness Data System (CDS); and the Fatality Analysis Reporting System (EARS) and the National Motor Vehicle Crash Causation Survey (NMVCCS).
2015-04-14
Journal Article
2015-01-1422
Neal Carter, Nathan A. Rose, David Pentecost
Abstract Several sources report simple equations for calculating the lean angle required for a motorcycle and rider to traverse a curved path at a particular speed. These equations utilize several assumptions that reconstructionists using them should consider. First, they assume that the motorcycle is traveling a steady speed. Second, they assume that the motorcycle and its rider lean to the same lean angle. Finally, they assume that the motorcycle tires have no width, such that the portion of the tires contacting the roadway does not change or move as the motorcycle and rider lean. This study reports physical testing that the authors conducted with motorcycles traversing curved paths to examine the net effect of these assumptions on the accuracy of the basic formulas for motorcycle lean angle. We concluded that the basic lean angle formulas consistently underestimate the lean angle of the motorcycle as it traverses a particular curved path.
2015-04-14
Journal Article
2015-01-1470
Takahiro Isshiki, Atsuhiro Konosu, Yukou Takahashi
It is anticipated that the currently used legform impact test methods using a legform impactor simulating only a lower limb of a pedestrian, such as the Flexible Pedestrian Legform Impactor (FlexPLI) and the EEVC legform impactor, cannot appropriately evaluate the probability of lower limb injuries of pedestrians in the cases of the collisions with vehicles equipped with high bumpers (high-bumper vehicles). The reason for this limitation is considered to be the lack of the upper body representation. However, the detailed analysis about the effect of the upper body has been limited. The latest legform impact test method using the FlexPLI attempts to compensate for the influences of the upper body by setting the impact height 50 mm higher than that of an actual pedestrian. It is anticipated that this compensation is not effective in collisions with high-bumper vehicles, however, the ineffectiveness of the compensation has not been clarified.
2015-04-14
Journal Article
2015-01-1441
Yibing Shi, Guy Nusholtz
Abstract Two methods of assessing the similarity of a set of impact test signals have been proposed and used in the literature, which are cumulative variance-based and cross correlation-based. In this study, a normalized formulation unites these two approaches by establishing a relationship between the normalized cumulative variance metric (v), an overall similarity metric, and the normalized magnitude similarity metric (m) and shape similarity metric (s): v=1 − m · s. Each of these ranges between 0 and 1 (for the practical case of signals acquired with the same polarity), and they are independent of the physical unit of measurement. Under generally satisfied conditions, the magnitude similarity m is independent of the relative time shifts among the signals in the set; while the shape similarity s is a function of these.
2015-04-14
Journal Article
2015-01-1426
Drew A. Jurkofsky
Abstract Photogrammetry from images captured by terrestrial cameras and manned aircraft has been used for many years to model objects, create scale diagrams and measure distances for use in traffic accident investigation and reconstruction. Due to increasing capability and availability, Unmanned Aircraft Systems (UAS), including small UAS (SUAS), are becoming a valuable, cost effective tool for collecting aerial images for photogrammetric analysis. The metric accuracy of scale accident scene diagrams created from SUAS imagery has yet to be compared to conventional measurement methods, such as total station and laser measurement systems, which are widely used by public safety officials and private consultants. For this study, two different SUAS were used to collect aerial imagery for photogrammetric processing using PhotoModeler software.
2015-04-14
Journal Article
2015-01-1433
R. Matthew Brach, Raymond M. Brach, Richard A. Mink
This paper presents a reconstruction technique in which nonlinear optimization is used in combination with an impact model to quickly and efficiently find a solution to a given set of parameters and conditions to reconstruct a collision. These parameters and conditions correspond to known or prescribed collision information (generally from the physical evidence) and can be incorporated into the optimized collision reconstruction technique in a variety of ways including as a prescribed value, through the use of a constraint, as part of a quality function, or possibly as a combination of these means. This reconstruction technique provides a proper, effective, and efficient means to incorporate data collected by Event Data Recorders (EDR) into a crash reconstruction. The technique is presented in this paper using the Planar Impact Mechanics (PIM) collision model in combination with the Solver utility in Microsoft Excel.
2015-04-14
Journal Article
2015-01-1482
Bisheshwar Haorongbam, Anindya Deb, Clifford Chou
Abstract Hat-sections, single and double, made of steel are frequently encountered in automotive body structural components. These components play a significant role in terms of impact energy absorption during vehicle crashes thereby protecting occupants of vehicles from severe injury. However, with the need for higher fuel economy and for compliance to stringent emission norms, auto manufacturers are looking for means to continually reduce vehicle body weight either by employing lighter materials like aluminum and fiber-reinforced plastics, or by using higher strength steel with reduced gages, or by combinations of these approaches. Unlike steel hat-sections which have been extensively reported in published literature, the axial crushing behavior of hat-sections made of fiber-reinforced composites may not have been adequately probed.
2015-04-14
Journal Article
2015-01-1489
Raed E. El-jawahri, Tony R. Laituri, Agnes S. Kim, Stephen W. Rouhana, Para V. Weerappuli
Abstract Transfer or response equations are important as they provide relationships between the responses of different surrogates under matched, or nearly identical loading conditions. In the present study, transfer equations for different body regions were developed via mathematical modeling. Specifically, validated finite element models of the age-dependent Ford human body models (FHBM) and the mid-sized male Hybrid III (HIII50) were used to generate a set of matched cases (i.e., 192 frontal sled impact cases involving different restraints, impact speeds, severities, and FHBM age). For each impact, two restraint systems were evaluated: a standard three-point belt with and without a single-stage inflator airbag. Regression analyses were subsequently performed on the resulting FHBM- and HIII50-based responses. This approach was used to develop transfer equations for seven body regions: the head, neck, chest, pelvis, femur, tibia, and foot.
2015-04-14
Journal Article
2015-01-1478
Michelle Heller, Sarah Sharpe, William Newberry, Alan Dibb, John Zolock, Jeffrey Croteau, Michael Carhart, Jason Kerrigan, Mark Clauser
Occupant kinematics during rollover motor vehicle collisions have been investigated over the past thirty years utilizing Anthropomorphic Test Devices (ATDs) in various test methodologies such as dolly rollover tests, CRIS testing, spin-fixture testing, and ramp-induced rollovers. Recent testing has utilized steer-induced rollovers to gain a deeper understand into vehicle kinematics, including the vehicle’s pre-trip motion (Asay et al., 2009; Asay et al., 2010). The current test series utilized ATDs in steer-induced rollovers to investigate occupant kinematics throughout the entire rollover sequence, from pre-trip vehicle motion to the final rest position. Two test vehicles (a sedan and a pickup truck) were fully instrumented, and each contained two restrained 50th percentile male ATDs in the front outboard seating positions. The pickup truck was equipped with rollover-activated side-curtain airbags that deployed prior to the first ground contact.
2015-04-14
Journal Article
2015-01-1481
Myles Wilson, David Aylor, David Zuby, Joseph Nolan
Abstract The Insurance Institute for Highway Safety (IIHS) evaluates autonomous emergency braking (AEB) systems as part of its front crash prevention (FCP) ratings. To prepare the test vehicles' brakes, each vehicle must have 200 miles on the odometer and be subjected to the abbreviated brake burnish procedure of Federal Motor Vehicle Safety Standard (FMVSS) 126. Other organizations conducting AEB testing follow the more extensive burnishing procedure described in FMVSS 135; Light Vehicle Brake Systems. This study compares the effects on AEB performance of the two burnishing procedures using seven 2014 model year vehicles. Six of the vehicles achieved maximum AEB speed reductions after 60 or fewer FMVSS 135 stops. After braking performance stabilized, the Mercedes ML350, BMW 328i, and Volvo S80 showed increased speed reductions compared with stops using brand new brake components.
2015-04-14
Journal Article
2015-01-1379
Hideki Matsumura, Shinichiro Itoh, Kenichi Ando
Recently, lithium ion cells are being used in more and more electric and hybrid motor vehicles. However, accidents due to thermal runaway of the cells have been reported, involving abnormal heat, smoke, and fire. Since each of these vehicles contains many cells, if the thermal runaway of one cell triggers that of another and thus causes thermal runaway propagation, a car fire or other serious accident may occur. This study aims to ensure the safety of motor vehicles with lithium ion cells. To identify such accident risks, we conducted a basic experiment to clarify the phenomenon of thermal runaway propagation following a thermal runaway. In the experiment, seven laminate-type lithium ion cells were tightly stacked one on another, with a thermocouple placed at the center of the surface of each cell. Then, the center of the cell in the middle of the seven stacked cells was overcharged to trigger a thermal runaway.
2015-04-14
Technical Paper
2015-01-1380
Kumar Kumar
According to the National Fire Protection Agency (NFPA), from the most recent available data, it was estimated that there were 164,000 highway vehicle fires in 2013 causing roughly 300 civilian fire deaths, 925 civilian fire injuries and $1.1 billion in property damages. In a modern automobile, the plastics content is dramatically higher than it was in 1972, when Federal Motor Vehicle Safety Standard (FMVSS) 302 was implemented. FMVSS 302 applies only to materials in the passenger compartment and was put in place to address accidental fires started from sources such as cigarettes, matches, etc. There has never been any regulation for the plastic materials used outside the vehicle interior, including those used in under-the-hood (UTH) applications, and this is true even for today’s automobiles. Combustible materials are roughly twice the weight and represent twice the heat content of the gasoline used in a typical passenger car today, constituting the major fire load.
2015-04-14
Journal Article
2015-01-1383
Andrew Blum, Richard Thomas Long
Fires involving cars, trucks, and other highway vehicles are a common concern for emergency responders. In 2013 alone, there were approximately 188,000 highway vehicle fires. Fire Service personnel are accustomed to responding to conventional vehicle (i.e., internal combustion engine [ICE]) fires, and generally receive training on the hazards associated with those vehicles and their subsystems. However, in light of the recent proliferation of electric drive vehicles (EDVs), a key question for emergency responders is, “what is different with EDVs and what tactical adjustments are required when responding to EDV fires?” The overall goal of this research program was to develop the technical basis for best practices for emergency response procedures for EDV battery incidents, with consideration for suppression methods and agents, personal protective equipment (PPE), and clean-up/overhaul operations.
2015-04-14
Technical Paper
2015-01-1384
Richard Young, Jing Zhang
In this age of the Internet of Things, people expect in-vehicle interfaces to work just like a smartphone. Our understanding of the reality of in-vehicle interfaces is quite contrary to that. We review the fundamental principles and metrics for automotive visual-manual driver distraction guidelines. We note the rise in portable device usage in vehicles, and debunk the myth of increased crash risk when conversing on a wireless device. We advocate that portable electronic device makers such as Apple and Google should adopt driver distraction guidelines for application developers (whether for tethered or untethered device use in the vehicle). We present two design implications relevant to safe driving. First, the Rule of Platform Appropriateness: design with basic principles of ergonomics, and with driver’s limited visual, manual and cognitive capacity, in mind. Second, the Rule of Simplicity: thoughtful reduction in the complexity of in-vehicle interfaces.
2015-04-14
Journal Article
2015-01-1381
Jason P. Huczek, R. Rhoads Stephenson
The Department of Transportation (DOT) National Highway Traffic Safety Administration (NHTSA) awarded a contract to Southwest Research Institute (SwRI) to conduct research and testing in accordance with Solicitation No. DTNH22-12-R-00574. The goal of this program was to develop and validate procedures and metrics to evaluate current and future detection, suppression, and exterior fire-hardening technologies that prevent or delay fire penetration into the passenger compartment of a motorcoach, in order to increase passenger evacuation time. The program was initiated with a literature review and characterization of the thermal environment of motorcoach fires and survey of engine compartments, firewalls, and wheel wells of motorcoaches currently in North American service. These characterizations assisted in the development of test methods and identification of the metrics for analysis.
2015-04-14
Technical Paper
2015-01-1382
Lisa Schei Blikeng, Siril Hegén Agerup
The number of electric vehicles has increased dramatically in recent years, especially in Norway were there today there are more than 35 000 electric cars, with a goal of 200 000 by 2020. With new Lithium-ion battery technology the battery packages is longer lasting and more useful for the normal family. Great interest of these vehicles leads to the discussion about fire safety. The major part of the thesis was to perform a full-scale fire experiment with a modern and drivable electric car, and in February 2013 a Peugeot iOn 2012 model was set on fire. The experiment was documented on video and thermocouples were used to measure temperatures.
2015-04-14
Technical Paper
2015-01-1387
Richard Young
This study revises the odds ratios (ORs) of secondary tasks estimated by Virginia Tech Transportation Institute (VTTI), who conducted the 100-Car naturalistic driving study. An independent and objective re-counting and re-analysis of all secondary tasks observed in the 100-Car databases removed misclassification errors and epidemiological biases. The corrected estimates of secondary task crude OR and Population Attributable Risk Percent (PAR%) for crashes and near-crashes vs. a random baseline were substantially lower for almost every secondary task, compared to the VTTI estimates previously reported. These corrected estimates were then adjusted for confounding from demographics, time of day, weekday-weekend, and closeness to junction by employing secondary task counts from a matched baseline from a later VTTI 100-Car analysis. This matched baseline caused most OR estimates to decline even further.
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