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Viewing 271 to 300 of 15832
2014-04-01
Technical Paper
2014-01-0491
Michael E. Zabala, Nicholas Yang, Stacy Imler, Ke Zhao, Rose Ray
Abstract Three years of data from the Large Truck Crash Causation Study (LTCCS) were analyzed to identify accidents involving heavy trucks (GVWR >10,000 lbs.). Risk of rollover and ejection was determined as well as belt usage rates. Risk of ejection was also analyzed based on rollover status and belt use. The Abbreviated Injury Scale (AIS) was used as an injury rating system for the involved vehicle occupants. These data were further analyzed to determine injury distribution based on factors such as crash type, ejection, and restraint system use. The maximum AIS score (MAIS) was analyzed and each body region (head, face, spine, thorax, abdomen, upper extremity, and lower extremity) was considered for an AIS score of three or greater (AIS 3+). The majority of heavy truck occupants in this study were belted (71%), only 2.5% of occupants were completely or partially ejected, and 28% experienced a rollover event. In the analyzed data set, none of the belted occupants experienced a complete ejection while 4.4% of unbelted occupants did experience a complete ejection.
2014-04-01
Technical Paper
2014-01-0492
Lisa P. Gwin, Herbert Guzman, Enrique Bonugli, William Scott, Mark Freund
Abstract There is a paucity of recent data quantifying the injury risk of forces and accelerations that act on the whole body in a back-to-front direction. The purpose of this study was to quantify the level of back-to-front accelerations that volunteers felt were tolerable and non-injurious. Instrumented volunteers were dropped supine onto a mattress, and their accelerations during the impact with the mattress were measured. Accelerometers were located on the head, upper thoracic and lower lumbar regions. Drop heights started at 0.6 m (2 ft) and progressed upward as high as 1.8 m (6 ft) based on the test subjects' consent. The test panel was comprised of male and female subjects whose ages ranged from 25 to 63 years of age and whose masses ranged from 62 to 130 kg (136 to 286 lb). Peak head, upper thoracic and lower lumbar accelerations of 25.9 g, 29.4 g and 39.6 g were measured. There was considerable restitution in the impacts with the mattress and the test subjects experienced changes in velocity (ΔVs) of 5.2-11.4 m/s (11.6-25.5 mph).
2014-04-01
Technical Paper
2014-01-0493
William R. Bussone, Michael Prange
Abstract Few studies have investigated pediatric head injury mechanics with subjects below the age of 8 years. This paper presents non-injurious head accelerations during various activities for young children (2 to 7 years old). Eight males and five females aged 2-7 years old were equipped with a head sensor package and head kinematics were measured while performing a series of playground-type activities. The maximum peak resultant accelerations were 29.5 G and 2745 rad/s2. The range of peak accelerations was 2.7 G to 29.5 G. The range of peak angular velocities was 4.2 rad/s to 22.4 rad/s. The range of peak angular accelerations was 174 rad/s2 to 2745 rad/s2. Mean peak resultant values across all participants and activities were 13.8 G (range 2.4 G to 13.8 G), 12.8 rad/s (range 4.0 rad/s to 12.8 rad/s), and 1375 rad/s2 (range 105 rad/s2 to 1375 rad/s2) for linear acceleration, angular velocity, and angular acceleration, respectively. The peak accelerations measured in this study were similar to older children performing similar tasks.
2014-04-01
Technical Paper
2014-01-0499
Timothy P. Austin, Peter A. Chisholm, Roger W. Schreiber, P. Michael Neal
Abstract In the investigation of a collision involving recreational watercraft, analytical methods are generally limited when compared to incidents involving land-based vehicles. As is indicated in previous publications, investigators often rely on time/distance relationships, human factors, the matching of damage to determine vessel positioning at impact, and the recollections of witnesses. When applicable, speed estimates are generally based on the boat engine's revolutions. By considering the engine speed, the drive gear ratio, the propeller pitch, and the likely slip of the propeller, an estimation of the boat's travel speed can be made. In more recent publications, it has been recognized that Event Data Recorder (EDR) technology incorporated into various Electronic Control Units (ECUs) used in automotive applications can be beneficial to collision investigation and reconstruction. These devices record data surrounding diagnostic occurrences, airbag deployments, and, with respect to some heavy vehicles, “last stop” and/or “sudden deceleration” events.
2014-04-01
Technical Paper
2014-01-0501
Roger Bortolin, Matthew Arbour, James Hrycay
Abstract Whether large or small, a truck fleet operator has to know the locations of its vehicles in order to best manage its business. On a day to day basis loads need to be delivered or picked up from customers, and other activities such as vehicle maintenance or repairs have to be routinely accommodated. Some fleets use aftermarket electronic systems for keeping track of vehicle locations, driver hours of service and for wirelessly text messaging drivers via cellular or satellite networks. Such aftermarket systems include GPS (Global Positioning System) technology, which in part uses a network of satellites in orbit. This makes it possible for the fleet manager to remotely view the location of a vehicle and view a map of its past route. These systems can obtain data directly from vehicle sensors or from the vehicle network, and therefore report other information such as fuel economy. The fleet manager can receive alerts when high-level brake applications occur, which could be an indication of tailgating or aggressive driving behavior.
2014-04-01
Technical Paper
2014-01-0504
Richard R. Ruth, Jeremy Daily
Abstract 2013 and 2014 Ford Flex vehicles and airbag control modules with event data recorders (EDRs) were tested to determine the accuracy of speed and other data in the steady state condition, to evaluate time reporting delays under dynamic braking conditions, and to evaluate the accuracy of the stability control system data that the module records. This recorder is from the Autoliv RC6 family and this is the first known external research conducted on post 49CFR Part 563 Ford EDRs. The vehicle was instrumented with a VBox and a CAN data logger to compare external GPS based speeds to CAN data using the same synchronized time base. The vehicle was driven in steady state, hard braking, figure 8 and yaw conditions. The Airbag Control Module (ACM) was mounted onto a moving linear sled. The CAN bus data from driving was replayed as the sled created recordable events and the EDR data was compared to the reference instrumentation. The accuracy and timing of the data on a second stability control CAN bus was verified, and the transfer function between the CAN bus data and the EDR data was mapped, such that EDR data from any set of CAN data can be predicted.
2014-04-01
Technical Paper
2014-01-0505
Greg Webster, Harold Clyde, Barry Hare, Mark Jakstis, Robert Landis, Lance Lewis, Ryan Buetzer
Abstract Four Toyota vehicles were tested in 12 test conditions to compare the Event Data Recorder (EDR) results with data gathered from onboard test instrumentation and the test protocol. The four Toyota vehicles tested were 2013 Model Year (MY) vehicles with EDRs that meet 49 CFR CH. V Part 563. While the previous Toyota EDR versions captured four pre-crash parameters, this generation Toyota EDR (12EDR) includes additional operating parameters and a faster sampling rate before the event trigger, including additional parameters not required by Part 563. The main focus of this research was to analyze the recording of the following driver inputs: accelerator pedal application, brake pedal application, steering wheel angle, and cruise control activation. The EDR-recorded inputs were compared with the values on the HS-CAN. The test results indicate that the 12EDR accurately recorded these driver inputs.
2014-04-01
Technical Paper
2014-01-0473
Anthony Dominic Cornetto, Jeffrey Suway, Ronny Wahba, Fawzi Bayan
Abstract Numerous studies have validated SIMON and DyMESH with respect to vehicle dynamics and crash analysis for accident reconstruction. The impetus for this paper is to develop an accessible methodology for calculating three-dimensional stiffness coefficients for HVE-SIMON and DyMESH. This method uses acceleration-time data (crash pulse) from a vehicle crash test, data that is widely available through the National Highway Traffic Safety Administration (NHTSA). The crash pulse, along with vehicle mass and impact speed, are used to calculate the force acting on the vehicle and the associated vehicle deflection time history. A technique for determining the area-deflection function is created from a computer model of the vehicle, HVE-SIMON, and basic photo-editing software. The calculated force divided by the associated area function (F/A) is plotted versus deflection and a third-order polynomial is then fit to the curve. The coefficients of this third-order polynomial are the A, B, C, and D stiffness coefficients.
2014-04-01
Technical Paper
2014-01-0472
Ryan Fix, David King, Travis Fricker
Abstract CRASH3 techniques are often used to reconstruct aligned offset vehicle impacts. The goal of this study was to evaluate the accuracy of the CRASH3 technique using a series of aligned staged collision with varying degrees of overlap. Five front-to-rear vehicle impacts using the same vehicle model were staged using 25, 33, 50, 75 and 100% overlap. Impact kinematics were measured using overhead high speed video. The CRASH3 coefficients and methods developed previously (SAE 2010-01-0069) were used to reconstruct the impact speed and speed changes of both vehicles based on the residual crush. Overall, the CRASH3 analysis yielded good results for the 33 to 100% overlap collisions: predicted speed changes were within 29% of the measured speed change and predicted impact speeds were within 16% of the measured impact speed. The CRASH3 analysis yielded poor results for the 25% overlap collision: the predicted speed changes were up to 59% different from the actual speed changes and the predicted impacts speeds were up to 54% different from the actual impact speeds.
2014-04-01
Technical Paper
2014-01-0470
Greg A. Sullenberger
Abstract A well-established methodology has often been used to calculate a speed-at-impact from the overall distance that a pedestrian is thrown as a result of a vehicle-pedestrian impact. (Searle, SAE #831622 and SAE #930659). The formulae were derived for use on typical road surfaces, such as asphalt, concrete, and grass. Significant testing has been done to validate the formulae on these normal surfaces. The current research was completed to assess if the same formulae are also applicable to lower-friction surfaces, e.g. snow, ice. Test dummies were impacted by automobiles or launched from a ramp in order to simulate the airborne trajectory of a vehicle-pedestrian collision. Speeds were measured with a radar unit and/or the analysis of high speed video. The overall distance traveled by the dummy from impact/launch to final rest was measured. A calculated friction value for the overall throw distance was based upon the known speed and distance and a known or approximated angle of takeoff.
2014-04-01
Technical Paper
2014-01-0468
Matthew Wood, Vivek Shekhawat, Tate Kubose, Rajeev Kelkar
Abstract Vehicle stiffness data are often used in crush energy analyses, in conjunction with conservation of momentum calculations, to compute vehicle speeds at impact for accident reconstruction purposes. The vehicle stiffness data are typically obtained from standardized impact tests, such as from the New Car Assessment Program (NCAP) or from Federal Motor Vehicle Safety Standard (FMVSS) tests. Ideally, these data are most applicable when obtained from a sister or clone subjected to an impact similar to the accident. However, when vehicle-specific data are not available, a common alternative is to use crush stiffness values for a generic vehicle population from the published literature. These publications are limited in number and, depending on the user's requirements, may have some inherent limitations. For example, use of the generic values may not readily apply to a recently manufactured subject vehicle involved in a side or rear-end impact. Of the currently published studies providing generic class stiffness data, one publication covers vehicles manufactured in the 1980's and 1990's, while another covers frontal impacts over 3 decades.
2014-04-01
Technical Paper
2014-01-0483
Thomas Rush, Jay Przybyla, Daniel Melcher, Christian Sax
Abstract Numerous mathematical models for reconstructing vehicle-pedestrian collisions have been developed over the years utilizing common sources of physical evidence. As sources of video data recording proliferate, new sources of physical evidence are now available in some cases. This paper presents an expanded methodology for analyzing video footage of actual pedestrian collisions, including both static and dynamic camera positions. Each video was analyzed using digitizing motion analysis software to quantify the pre-impact and post-impact trajectories and speeds of the vehicle, the pedestrian, and the camera position for each collision. The relationship between vehicle speed and pedestrian throw distance has frequently been used in collision reconstruction to answer questions regarding vehicle/pedestrian impacts. Several approaches to reconstructing vehicle/pedestrian collisions have been developed and published in the literature using equations derived from empirical models, principles of mechanics, or hybrid approaches.
2014-04-01
Technical Paper
2014-01-0478
Wade D. Bartlett, Duane Meyers
Abstract The evasive capabilities of motorcycles and riders are often an important consideration when analyzing a motorcycle crash. Specifically, the longitudinal distance or time required for a motorcycle to move laterally some distance can be of critical interest. Previous publications on this topic have not all measured the same thing and have often included limited test data so their results can be difficult to compare or apply. In addition to reviewing some of the literature on the topic, this paper will present the results of a series of tests conducted with four riders on four motorcycles swerving 2 m (6.5 ft) to their left after passing through a gate at speeds of 40 to 88 km/h (25 to 55 mi/h). The most recent testing involved relatively skilled riders who had faster transitions and greater willingness to lean than the “average” rider generally described in the literature. Separating the perception-reaction time from the evaluation of the turn-away maneuver itself simplifies the analysis, though wide individual performance variation still exists.
2014-04-01
Technical Paper
2014-01-1398
Ahmed A. Abdel-Rehim, Ahmed A.A. Attia
Abstract The effect of magnetic field has attracted many researchers to investigate the impact of this type of force on different applications such as combustion and water. Different systems supported by many patents were introduced to the market to treat these applications. In the present study, a series of experiments were conducted to explore the impact of magnetic fuel treatment on engine performance. The magnetic field was produced from two different sources based on permanent and electromagnetic coils. Two engines with different configurations were used. Three fuels were tested, gasoline and diesel as liquid fuels and natural gas as a gaseous fuel. Vast numbers of experiments at different operating conditions were conducted on the two engines. Fuel consumption, output power, and exhaust emissions were analyzed under the exposure of magnetic field. Gasoline was the most affected fuel while other fuels showed less or negligible effect. Magnetic field strength was a key parameter to have any impact on engine performance.
2014-04-01
Technical Paper
2014-01-1715
Parul Goyal, Feng Liang, Olof Oberg
Abstract The aim of the paper is to describe how Volvo Construction Equipment uses a virtual product development process to analyze potential risks, find root causes and optimize future product development. A model based method is used to analyze a potential risk in the design of Wheel Loader transmissions. The risk was recognized from failure mode and effect analysis (FMEA), and a simulation model using AMESim modeling tool was developed to analyze the behavior of the new design. Together with test rig result, it is proved that the model based method gives a considerably accurate prediction of the system behavior. By using the model based approach, lead time for development process is reduced and important feedbacks from simulation model are obtained on early stage of the development. This paper further presents the use of the simulation model as a tool to predict the potential risks in the extreme operating conditions, which are difficult to test on the vehicle test bench.
2014-04-01
Technical Paper
2014-01-1903
Thomas Juergen Boehme, Tobias Sehnke, Matthias Schultalbers, Torsten Jeinsch
Abstract In this paper an energy management is proposed which is optimal to certain driving scenarios which can be clustered into freeway, rural and urban situations. This strategy is non-predictive but uses information about the current driving situation provided by modern navigation systems to identify the current road type. Based on this information a set of simplified optimal control problems are solved offline via an indirect shooting algorithm. By relaxation of the problem formulation, the solutions of these optimal control problems can be stored into easily implementable maps. The energy management control is then determined from these maps during vehicle operation using the current road type, the vehicle speed and the required wheel-torque. The strategy is implemented in a dSPACE MicroAutoBox and validated on a near mass-production vehicle. The proposed methodology has shown fuel savings on a real world drive cycle. Additionally, robustness aspects have been considered in a MATLAB/Simulink based simulation environment.
2014-04-01
Collection
This technical paper collection focuses on the latest research related to methods and techniques for reconstructing vehicular crashes involving wheeled and tracked vehicles, pedestrians, and roadside features. Emphasis is placed on experimental data and theoretical methods that will enable reconstructionists to identify, interpret and analyze physical evidence from vehicular crashes.
2014-04-01
Technical Paper
2014-01-0437
Rudolf Mortimer, Errol Hoffmann, Aaron Kiefer
Abstract Relative velocity detection thresholds of drivers are one factor that determines their ability to avoid rear-end crashes. Laboratory, simulator and driving studies show that drivers could scale relative velocity when it exceeded the threshold of about 0.003 rad/sec. Studies using accident reconstruction have suggested that the threshold may be about ten times larger. This paper discusses this divergence and suggests reasons for it and concludes that the lower value should be used as a true measure of the psychological threshold for detection of relative velocity.
2014-04-01
Technical Paper
2014-01-0158
David LeBlanc, Mark Gilbert, Stephen Stachowski, Rini Sherony
Pre-collision systems (PCS) use forward-looking sensors to detect the location and motion of vehicles ahead and provide a sequence of actions to help the driver either avoid striking the rear-end of another vehicle or mitigate the severity of the crash. The actions include driver alerts, amplification of driver braking as distance decreases (dynamic brake support, DBS), and automatic braking if the driver has not acted or has not acted sufficiently (crash imminent braking, CIB). Recent efforts by various organizations have sought to define PCS objective test procedures and test equipment in support of consumer information programs and potential certification. This paper presents results and insights from conducting DBS and CIB tests on two production vehicles sold in the US. Eleven scenarios are used to assess the systems' performance. The two systems' performance shows that commercial systems can be quite different. Also demonstrated is the experience with test equipment, including a towable target that has been designed for resiliency and radar signature, a braking robot, and bumper guard.
2014-04-01
Technical Paper
2014-01-0422
Lothar Seybold, Bryan Styles, Ioannis Lazaridis, Hans-Joerg Kneusels
The European Commission (EC) as well as the United States Environmental Protection Agency (EPA) published legislations to regulate or encourage the use of low Global Warming Potential (GWP) refrigerants applied to Mobile Air Conditioning (MAC) systems. Europe mandates a GWP less than 150 of MAC refrigerants for new vehicle types. The thermodynamic refrigerant properties of R-1234yf are slightly different from the properties of R-134a, currently used in MAC systems. Although the basic material data show that R-1234yf is flammable, ignition tests performed for an automotive engine under-hood environment reveal design and packaging influences of its ignition behavior. After extensive collaborative research in 2009, the Society of Automotive Engineers Cooperative Research Team (SAE CRP1234) concluded that R-1234yf is suitable for use in automotive applications. Further ignition risk assessment regarding R-1234yf usage in MAC systems was done by SAE CRP1234-4 in 2013. They concluded that “risks are still very small compared to the risks of a vehicle fire from all causes and well below risks that are commonly viewed as acceptable by the general public.”
2014-04-01
Technical Paper
2014-01-0420
Mathias Poklitar, Lothar Seybold
As part of the launch of the refrigerant R-1234yf there were a number of studies done regarding the ignition behavior of this new refrigerant in passenger cars. These tests were conducted by a number of automobile manufacturers, component suppliers, and the refrigerant supplier under laboratory conditions at the component and vehicle level. In November 2009 the international automotive industry concluded that the R-1234yf can be used safely in automotive air conditioning systems. Further tests were conducted by different automobile manufacturers, suppliers, and the refrigerant supplier under various laboratory and vehicle operation conditions means hot surfaces in the engine compartment. A number of vehicle manufactures have conducted full vehicle crash tests. In this paper, real world accidents are analyzed using the German In-Depth Accident Study (GIDAS) database as well as the thermal parameters for ignition of R-1234yf, i.e. concentration and surface temperature to create a worst-case scenario.
2014-04-01
Technical Paper
2014-01-0419
Bryan Styles, Jeffrey Santrock, Curtis Vincent, Michael Leffert, Narasimha Putcha
An evaluation methodology has been developed for assessing the suitability of R-1234yf in vehicles. This relates primarily to evaluating the flammability of R-1234yf in the engine compartment during a frontal collision. This paper will discuss the process followed in the methodology, the technical rationale for this process, and the results of the analysis. The specific types of analysis included in the methodology are: exhaust-system thermal characterization, computer simulated crash tests, actual crash tests, teardown and examination of crashed parts, and releases of refrigerant onto hot exhaust manifolds. Each type of analysis was logically ordered and combined to produce a comprehensive evaluation methodology. This methodology has been applied and demonstrates that R-1234yf is difficult to ignite when factors that occur in frontal crashes are simultaneously considered. Factors considered in this analysis include: crush and deformation of the vehicle structure, airflow in the engine compartment, exhaust system temperatures during different driving scenarios, and coolant release due to damage of the engine coolant system.
2014-04-01
Technical Paper
2014-01-0448
Richard Young
This study reanalyzes the data from a recent experimental report from the University of Utah investigating the effect on driving performance of auditory-vocal secondary tasks (such as cell phone and passenger conversations, speech-to-text, and a complex artificial cognitive task). The current objective is to estimate the relative risk of crashes associated with such auditory-vocal tasks. Contrary to the Utah study's assumption of an increase in crash risk from the attentional effects of cognitive load, a deeper analysis of the Utah data shows that driver self-regulation provides an effective countermeasure that offsets possible increases in crash risk. For example, drivers self-regulated their following distances to compensate for the slight increases in brake response time while performing auditory-vocal tasks. This new finding is supported by naturalistic driving data showing that cell phone conversation does not increase crash risk above that of normal baseline driving. The Utah data are next compared to those from a larger study that included visual-manual as well as auditory-vocal tasks.
2014-04-01
Technical Paper
2014-01-0446
Richard Young
A key aim of research into cell phone tasks is to obtain an unbiased estimate of their relative risk (RR) for crashes. This paper re-examines five RR estimates of cell phone conversation in automobiles. The Toronto and Australian studies estimated an RR near 4, but used subjective estimates of driving and crash times. The OnStar, 100-Car, and a recent naturalistic study used objective measures of driving and crash times and estimated an RR near 1, not 4 - a major discrepancy. Analysis of data from GPS trip studies shows that people were in the car only 20% of the time on any given prior day at the same clock time they were in the car on a later day. Hence, the Toronto estimate of driving time during control windows must be reduced from 10 to 2 min. Given a cell phone call rate about 7 times higher when in-car than out-of-car, and correcting for misclassification of some post-crash calls as pre-crash, the final required downward adjustment of the Toronto and Australian RR estimates is about 7 times.
2014-04-01
Technical Paper
2014-01-0469
R. Matthew Brach, Raymond M. Brach, Katherine Pongetti
Little experimental data have been reported in the crash reconstruction literature regarding high-speed sideswipe collisions. The Insurance Institute for Highway Safety (IIHS) conducted a series of high-speed, small overlap, vehicle-to-barrier and vehicle-to-vehicle crash tests for which the majority resulted in sideswipe collisions. A sideswipe collision is defined in this paper as a crash with non-zero, final relative tangential velocity over the vehicle-to-barrier or vehicle-to-vehicle contact surface; that is, sliding continues throughout the contact duration. Using analysis of video from 50 IIHS small overlap crash tests, each test was modeled using planar impact mechanics to determine which were classified as sideswipes and which were not. The test data were further evaluated to understand the nature of high-speed, small overlap, sideswipe collisions and establish appropriate parameter ranges that can aid in the process of accident reconstruction. An example reconstruction of a small overlap, sideswipe collision using optimization methods based on the planar impact mechanics model is included in the paper.
2014-04-01
Technical Paper
2014-01-0503
Ada Tsoi, Nicholas Johnson, H. Gabler
This study evaluated the accuracy of 75 Event Data Recorders (EDRs) extracted from model year 2010-2012 Chrysler, Ford, General Motors, Honda, Mazda, and Toyota vehicles subjected to side-impact moving deformable barrier crash tests. The test report and vehicle-mounted accelerometers provided reference values to assess the EDR reported change in lateral velocity (delta-v), seatbelt buckle status, and airbag deployment status. Our results show that EDRs underreported the reference lateral delta-v in the vast majority of cases, mimicking the errors and conclusions found in some longitudinal EDR accuracy studies. For maximum lateral delta-v, the average arithmetic error was −3.59 kph (−13.8%) and the average absolute error was 4.05 kph (15.9%). All EDR reports that recorded a seatbelt buckle status data element correctly recorded the buckle status at both the driver and right front passenger locations. For equipped vehicles that reported side torso, side curtain, and frontal airbag deployment information, all vehicles recorded the correct status.
2014-04-01
Technical Paper
2014-01-0508
John Patalak, Thomas Gideon, Don Krueger
First required in 1970 in NASCAR® (National Association for Stock Car Auto Racing, Inc) the driver's window safety net or driver's window net has continually evolved and improved. The driver's window net has played an important role in protecting race car drivers from injury. Driver's window nets were originally used to help keep the driver's upper torso, head and arms inside the interior of the race vehicle during crashes. As restraint systems were improved, the role of the driver's window net in stock car racing has transitioned to keeping flailing hands inside the interior of the car while also serving as a shield to protect the driver from intruding debris. This paper describes three separate window net and window net mounting tests and the use of these tests to design an improved window net mounting system. Also shown are test results of previously used window net mounting systems and the improved NASCAR system which has been incorporated into the 2013 NASCAR Sprint Cup, Nationwide Series, and Camping World Truck Series vehicles.
2014-04-01
Technical Paper
2014-01-0537
Joyce Lam, Nate J. Dennis, Jeff Dix, Martin Lambrecht, Ryuuji Ootani
The National Highway Traffic Safety Administration (NHTSA) and the Insurance Institute for Highway Safety (IIHS) have both developed crash test methodologies to address frontal collisions in which the vehicle's primary front structure is either partially engaged or not engaged at all. IIHS addresses Small Overlap crashes, cases in which the vehicle's primary front energy absorbing structure is not engaged, using a rigid static barrier with an overlap of 25% of the vehicle's width at an impact angle of 0°. The Institute's Moderate Overlap partially engages the vehicle's primary front energy absorbing structure using a deformable static barrier with 40% overlap at a 0° impact angle. The NHTSA has developed two research test methods which use a common moving deformable barrier impacting the vehicle with 20% overlap at a 7° impact angle and 35% overlap at a 15° impact angle respectively. In this paper, the authors present a case study in which an exemplar mid-size sedan was subjected to all four impact conditions.
2014-04-01
Technical Paper
2014-01-0518
Bingbing Nie, Qing Zhou, Yong Xia, Jisi Tang
Vehicle hood styling has significant influence on headform kinematics in assessment tests of pedestrian impact protection performance. Pedestrian headform kinematics on vehicle front-end models with different hood styling characteristics is analyzed based on finite element modeling. More elevated feature lines near hood boundary and the following continuous hood surface towards fender will result in a different headform motion. It can lead to larger deformation space, more rotation and earlier rebound of the headform impactor, which will benefit the head impact protection performance. In addition, hood geometry characteristics such as hood angle and curvature have effects on structural stiffness. Therefore, inclusion of considerations on pedestrian head protection into the vehicle hood styling design stage may lead to a more effective and efficient engineering design process on headform impact analysis.
2014-04-01
Technical Paper
2014-01-0517
Dietmar Otte, Birgitt Wiese
This study deals with the risk of injury to the bicyclist's head and the benefits of wearing a bicycle helmet in terms of reduction of injury severity or even injury avoidance. The accident data of 4,245 injured bicyclists as a randomized sample, collected by a scientific research team within the GIDAS project (German In-Depth Accident Study) were analyzed. Given that head injuries result in approximately 40% of bicycle-related crashes, helmet usage provides a sensible first-level approach for improving incidence and severity of head injuries. The effectiveness of the bicycle helmet was examined using descriptive and multivariate analysis for 433 bicyclists with a helmet and 3,812 bicyclists without a helmet. Skull fractures, severe brain injuries and skull base fractures were up to 80% less frequent for bicyclists wearing a helmet. Among individuals 40 years of age and older, a significant increase of severe head injuries occurred if no helmet was used compared to younger persons with helmet.
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