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2015-05-20
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This is the electronic format of the Journal.
2015-04-14
Technical Paper
2015-01-1491
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. To address these scenarios, IIHS has incorporated small overlap impact in the NCAP rating. Similarly, NHTSA is developing an oblique test to address this. Most of the vehicles which are on road scored low when tested for these impact scenarios. This is mainly because most of the energy-absorbing structures (in a vehicle) such as rails and crush boxes during a high speed crash do not get engaged with the impactor as the overlap is very small.
2015-04-14
Technical Paper
2015-01-1489
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 restraint, impact speeds, severities, and FHBM age). For each impact, two restraint systems were evaluated: a standard three-point vehicle 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 different body regions: the head, neck, chest, pelvis, femur, tibia, and foot.
2015-04-14
Technical Paper
2015-01-1492
Kazunobu Ogaki, Takayuki Kawabuchi, Satoshi Takizawa
We test the mid-size sedan according to NHTSA Oblique test to assess the occupant protection and to provide possible design changes to improve the oblique collision performance. This test result predicted high potential injury for BrIC, chest deflection, and lower extremities. Injury reductions could likely be achieved through optimization of the restraint devices. We focus to reduce the lower extremity injury. Traditionally, lower extremity injuries are often mitigated by reducing the intrusion of the cabin’s dashboard lower region; however, this type of design change can lead to a significant increase in vehicle weight. Increasing the energy absorbed within the engine compartment is more efficient than reinforcing the passenger compartment.
2015-04-14
Technical Paper
2015-01-1490
Tony R. Laituri, Scott Henry, Kaye Sullivan
A study of belted driver injury in various types of frontal impacts in the US field data was conducted. Specifically, subject to the Frontal Impact Taxonomy of Sullivan et al. (2008), injury potential of belted drivers in non-rollover, frontal impacts in the National Automotive Sampling System (NASS) was assessed. The field data pertained to 1985 - 2013 model-year light passenger vehicles in 1995 - 2012 calendar years of NASS. Two levels of injury were considered: AIS2+ and AIS3+. For ease of presentation, we grouped the injury data into lower- or upper-body regions. Frontal impacts were binned into eight taxonomic groups: Full-engagement, Offset, Narrow, Oblique, Side-swipe corner, High/low vert (i.e., over- and under-ride crashes), DZY-No rail (i.e., distributed crashes, but with negligible frame rail involvement), and Other. The results of the survey yielded insights into the distribution of belted-driver injury in NASS.
2015-04-14
Technical Paper
2015-01-1488
Adam G.M. Cook, Moustafa El-Gindy, David Critchley
This work investigates the multi-objective optimization methods for Front Underride Protection Devices (FUPDs) using varying meta-modeling and direct optimization techniques, while implementing several materials and minimizing cost of the design. The developed dsFUPD F9 design for a Volvo VNL was subjected to a modified ECE R93 quasi-static loading to objectify deformations. A developed application was needed to objectify the cost as a third target objective to minimize with mass and deformation of the design. NSGA-II, SPEA-II genetic algorithms and adaptive simulated annealing optimization methods were under investigation in combination with three meta-modeling techniques; Feedforward Neural Network, Radial Basis Function Network, and Kriging. Leapfrog LFOPC algorithm hybridized forms of genetic algorithms and adaptive simulated annealing was also investigated.
2015-04-14
Technical Paper
2015-01-1486
Craig A. Markusic, Ram Songade
Full vehicle crash simulations typically require several days of effort from a highly skilled FE (finite element) analyst to set-up, execute, and analyze. The goal of this project was to create a simplified FE model of a side crash utilizing the same sophisticated software (LS-DYNA) that the FE analysts use along with a custom graphical user interface (GUI) that will allow an inexperienced user to set-up, execute, and analyze a number of side impact scenarios in a matter of hours, not days, and with very little training. The GUI allows the user to easily modify the performance characteristics of the side impact system that are critical to side crash performance including but not limited to intrusion rate, door liner stiffness, side airbag stiffness, side airbag time to fire, etc. The user can then compile and submit the model with a few simple clicks of a button.
2015-04-14
Technical Paper
2015-01-1439
Toshiyuki Yanaoka, Yasuhiro Dokko, Yukou Takahashi
To evaluate vehicle safety performance for Traumatic Brain Injuries (TBIs) in crashes, comprehensive injury criteria is required. Few research results for injury criteria focused on Diffuse Axonal Injury (DAI) in crashes or pedestrian impacts exist. We developed injury criteria based on the rotational rigid body motion of the head for occupant and pedestrian crashes. We used the mid-sized male human head/brain FE model to investigate correlation between injury criteria based on the rotational rigid body motion of the head and intracranial responses related to DAI. The input pulses applied to the skull of the head/brain model were determined from the head acceleration data, and articulated rigid body simulation results of frontal occupant and pedestrian crashes. Results showed low applicability of the injury criteria to pedestrian impacts, presumably due to the maximum rotational velocity occurring before head contact to the vehicle.
2015-04-14
Technical Paper
2015-01-1442
Wolfgang Sinz, Jörg Moser, Christoph Klein, Robert Greimel, Karsten Raguse, Class Middendorff, Christina Steiner
Precise three-dimensional dummy head trajectories during crash tests are very important for vehicle safety development. To determine precise trajectories with an accuracy of approximately 5 millimetres, three-dimensional video analysis is an approved method. Therefore the tracked body is to be seen on at least two cameras during the whole crash term, which is often not given (e.g. head dips into the airbag). This non-continuity problem of video analysis is surmounted by numerical integration of differential un-interrupted electrical rotation and acceleration sensor signals mounted into the tracked body. Problems of this approach are unknown sensor calibration errors and unknown initial conditions, which result in trajectory deviations above 10 centimetres.
2015-04-14
Technical Paper
2015-01-1432
Jeffrey Aaron Suway, Judson Welcher
Accident reconstruction experts are often asked to evaluate the visibility and conspicuity of objects in the roadway. It is common for some of these objects, and required by Federal Motor Vehicle Safety Standard (FMVSS) No. 108 for certain vehicles and trailers, to have red and white DOT-C2 retroreflective tape installed on several locations. Retroreflective tape is designed to reflect light back towards the light source, at the same entrance angle. FMVSS No. 108 has performance requirements for retroreflective tape at different entrance angles, up to 45 degree. The federal requirement for minimum performance of the retroreflective tape at 45 degrees is significantly less than the federal requirement for minimum performance of the retroreflective tape at 4 degrees. Additionally, the federal requirement for the minimum performance of white retroreflective tape is significantly different than the federal requirement for the minimum performance of red retroreflective tape.
2015-04-14
Technical Paper
2015-01-1429
Jeffrey Aaron Suway, Judson Welcher
Federal Motor Vehicle Safety Standard (FMVSS) No. 108 has requirements for retroreflective tape at different entrance angles, up to 45 degree. In the author’s preliminary research, all DOT-C2 retroreflective tape on the market is advertised as meeting and exceeding FMVSS No. 108 requirements. The author’s literature review revealed that there have been no peer-reviewed publications measuring the performance of commercially available DOT-C2 retroreflective tape. Therefore, without additional study, an accident reconstruction expert cannot know exactly how a specific type of compliant tape would perform, beyond the minimum federal requirements. Therefore, the authors have measured the performance of different types of retroreflective tape with a laboratory grade retroreflectometer. The authors attempted to study a range of popular, commercially available, DOT-C2 retroreflective tape. In this study, 3M 963, 3M 983, Grote, and Trucklite DOT-C2 retoreflective tape was used.
2015-04-14
Technical Paper
2015-01-1430
Brian Gilbert, Joseph McCarthy, Ron Jadischke
Objectives: The analysis and modeling of vehicle crush in accident reconstruction has traditionally been based upon the use of linear crush-based, stiffness coefficients. Recent research has allowed for the calculation and implementation of non-linear crush coefficients. Through the use of Engineering Dynamics Corporation (EDC) accident reconstruction software Human-Vehicle-Environment (HVE), which contains the collision algorithm called DyMESH (DYnamic MEchanical SHell), these coefficients have increased the accuracy of predicted crash pulse data. Research on non-linear crush coefficients thus far has been limited to frontal impacts into rigid barriers. Side Impact tests are typically more complex than a frontal collision testing. One form of side impact tests involve a Moving Deformable Barrier (MDB) impacting a stationary subject vehicle at a crab angle of 26-27 degrees.
2015-04-14
Technical Paper
2015-01-1422
Neal Carter, Nathan A. Rose, David Pentecost
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. For this study, the authors conducted physical testing 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 required for a motorcyclist traversing a curved path.
2015-04-14
Technical Paper
2015-01-1420
John C. Steiner
Traditional accident reconstruction analysis methodologies include the study of the crush-energy relationship of vehicles. By analyzing the measured crush from a vehicle involved in a real world accident, to crush measured at a known energy in a crash test, the real world vehicle’s damage energy, the forces of the impact, and change-in-velocity (or Delta-V) can be evaluated. The largest source of publically available crash tests is from the National Highway Traffic Safety Administration (NHTSA), which conducts and reports on numerous Federal Motor Vehicle Safety Standard (FMVSS) compliance and New Car Assessment Program (NCAP) testing for many passenger vehicles for sale in the United States.
2015-04-14
Technical Paper
2015-01-1423
Massoud Tavakoli, Niraj Pandya
The purpose of this paper is to add insight on the difference between the straight-line versus curved-path (as in an evasive maneuver) drag factor of a vehicle when ABS is active. A large number of skid runs were performed with a single vehicle under combinations of wet and dry surface, straight and curved paths, with and without ABS. For the curved paths, two different radii were used (80 and 139 ft) and braking was conducted with care to maintain the curve with minimal or no loss of control such as “fish tailing.” A VC4000 was used to collect the data. The data was processed in several ways to compare and contrast the conventional use of such instruments for drag factor determination versus ways that the data can be used at a finer resolution. For example, the drag factor based on using 0.2g as the threshold for the start of braking was compared to the drag factor based on the actual observable skid mark length.
2015-04-14
Technical Paper
2015-01-1421
Dennis Turriff, David J. King, James Bertoch
Vehicle rollovers generate complicated damage patterns as a result of multiple vehicle-to-ground contacts. The goal of this work was to isolate and characterize specific directional features in coarse- and fine-scale scratch damage generated during a rollover crash. Four rollover tests were completed using stock 2001 Chevrolet Trackers. Vehicles were decelerated and launched from a rollover test device to initiate driver’s side leading rolls onto concrete and dirt surfaces. Gross vehicle damage and both macroscopic and microscopic features of the scratch damage were documented using standard and macro lenses, a stereomicroscope, and a scanning electron microscope (SEM). The most evident indicators of scratch direction, and thus roll direction, were accumulations of abraded material found at the termination points of scratch-damaged areas.
2015-04-14
Technical Paper
2015-01-1428
Shane Richardson, Andreas Moser, Tia Lange Orton, Roger Zou
Currently techniques that can be used to evaluate and analyse lateral impact speeds of vehicle crashes with poles are based on measuring the deformation crush and using lateral crash stiffness data to estimate the impact speed. However, in some cases the stiffness data is based on broad object side impacts rather than pole impacts. The premise is that broad object side impact tests can be used for narrow object impacts; previous authors have identified the fallacy of this premise. Publicly available pole crash test data is evaluated. A range of simulated pole impact tests at various speeds and impact angles are conducted on validated publicly available Finite Element Vehicle models of a 1991 Ford Taurus, a 1994 Chevrolet C2500 and a 1997 Geo Metro (Suzuki Swift), providing a relationship between impact speed, crush depth and impact angle. This paper builds on previous publications and contains additional pole tests and new Finite Element Analyses.
2015-04-14
Technical Paper
2015-01-1479
Adria Ferrer, Eduard Infantes
In September 2009 the National Highway Traffic Safety Administration (NHTSA) published a report that investigated the incidence of fatalities to belted non-ejected occupants in frontal crashes involving late-model vehicles. The report concluded that after exceedingly severe crashes, the largest number of fatalities occurred in crashes involving poor structural engagement between the vehicle and its collision partner, such as corner impacts, oblique crashes, or impacts with narrow objects. In response to these findings, NHTSA designed and developed a test procedure intended to mitigate the risk of injuries and fatalities related to motor vehicle crashes involving poor structural engagement. This research demonstrated that an offset impact between a moving deformable barrier (RMDB) and a stationary vehicle at a 15º angle can reproduce vehicle crush, occupant kinematics, and risk of injury seen in vehicle-to-vehicle crashes.
2015-04-14
Technical Paper
2015-01-1482
Bisheshwar Haorongbam, Anindya Deb, Clifford Chou
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
Technical Paper
2015-01-1481
Myles Wilson, David Aylor, David Zuby, Joseph Nolan
The Insurance Institute for Highway Safety (IIHS) evaluates autonomous emergency braking systems as part of its front crash prevention (FCP) ratings. The evaluation is based on the vehicle’s ability to avoid or mitigate crashes at 20 and 40 km/h. To ensure that the tested vehicle’s brakes are in service condition, IIHS protocol requires each test vehicle accumulate between 200 and 5,000 miles before testing and also complete a brake warm-up with 10 stops from 56 km/h at 5 to 6 m/s2 and three stops from 72 km/h that activate ABS. Other organizations, including automakers, conducting AEB testing follow the brake burnishing procedure described in Federal Motor Vehicle Safety Standard (FMVSS) 135; Light Vehicle Brake Systems. Before testing compliance with the standard, FMVSS 135 requires test vehicles make 200 stops from 80 km/h at a deceleration of 3.0 m/s2.
2015-04-14
Technical Paper
2015-01-1484
Daniel E. Toomey, Eric S. Winkel, Ramnarain Krishnaswami
The evolution of airbag sensing system design has been rapid as electromechanical sensors used in earlier front airbag applications have been replaced by multi-point electronic sensors used to discriminate collision mechanics for potential airbag deployment in front, side and rollover accidents. In addition to multi-point electronic sensors, advanced airbag systems incorporate a variety of state sensors such as seat belt use status, seat track location, and occupant size classification that are taken into consideration by airbag system algorithms and occupant protection deployment strategies. Historically, traditional reconstruction methods and full scale vehicle crash testing were the primary means available to evaluate the field performance of passenger vehicle airbag systems. Electronic sensing systems have allowed for the advent of electronic data recorders (EDRs), which over the past decade, have provided increasingly more information related to airbag deployment events.
2015-04-14
Technical Paper
2015-01-1483
Anindya Deb, N Shivakumar, Clifford Chou
Rigid polyurethane (PU) foam finds wide applications as a lightweight material in impact safety design such as improving occupant safety in vehicle crashes. The two principal reacting compounds for formulating such a foam are variants of polyol and isocyanate. In the present study, an alternative mechanical engineering-based approach for determining, with confidence, the desirable ratio of reacting compounds for formulation of a rigid/crushable PU foam for mechanical applications is demonstrated. According to the present approach, PU foam samples are prepared by varying the mixing ratio over a wide range. The desirable mixing ratio is shown to be the one that optimizes key mechanical properties under compression such as total absorbed energy, specific absorbed energy and energy absorption efficiency.
2015-04-14
Technical Paper
2015-01-1469
Yan Wang, Taewung Kim, Yibing Li, Jeff Crandall
The characteristic of neck plays an important role on the kinematics and injury of pedestrian’s neck and head during the impact with vehicle, and the accuracy of the mathematical model affects the analysis results directly. A new mathematical pedestrian model has been developed in University of Virginia (UVA), which combines the advantages of both TNO facet occupant model and the lower extremity with more accuracy of biomechanical characteristics. So in this new pedestrian model, the occupant’s facet neck model developed by TNO is used to evaluate the pedestrian’s kinematics and dynamic response. Since the neck is special developed for occupants, the mechanical characteristics for lateral impact may not as good as that of frontal impact.
2015-04-14
Technical Paper
2015-01-1474
Jeries Jacob Abou-Hanna
Rollover Protective Structures (ROPS) are manufactured typically from components that require forming such as pipe bending process. The manufacturing process creates residual stresses and shape deformities in the pipe structure. These parameters in turn may affect the strength of the pipe to bear the load during rollover. Conventional modeling does not capture the effects of residual stresses and shape irregularities in the pipe resulting from forming. A detailed analysis is therefore required to determine the significance of the manufacturing process on the strength of ROPS. Finite Element Method (FEM) is employed to simulate the bending process. Residual stress and deformation data from bending process analysis are used to further investigate failure of the structure under different loading conditions. The maximum load the structure can withstand, before it loses its stiffness, under a specific displacement is referred to here as failure load.
2015-04-14
Technical Paper
2015-01-1473
Kalu Uduma
The National Highway Transportation Safety Administration (NHTSA) issued the FMVSS 226 ruling in 2011. It established test procedures to evaluate ejection mitigation countermeasures that are intended to help minimize the likelihood of a complete and/or partial ejection of vehicle occupants through the side windows during rollover or side impact events. One of the countermeasures that may be used for compliance of this new safety ruling is a deployable restraint; specifically a Side Airbag Inflatable Curtain (SABIC). This paper discusses how three key phases of the optimization strategy in the Design for Six Sigma (DFSS), namely, Identify; Optimize and Verify (I_OV), were implemented in CAE to develop an improved simulation response, with respect to the FMVSS 226 test requirements of a SABIC. The simulated SABIC system is intended for a generic SUV and potentially also for a generic Truck type vehicle.
2015-04-14
Technical Paper
2015-01-1475
Alan F. Asay, Jarrod Carter, James Funk, Gregory Stephens
A follow-up case study on rollover testing was conducted with an instrumented single full-size SUV under real-world conditions. The purpose of this study was to conduct a well-documented rollover event that could be utilized in evaluating various reconstruction methods and techniques over the phases associated with rollover accidents. The phases documented and discussed inherent to rollovers are: loss-of-control, trip, and rolling phases. With recent advances in technology, new devices and techniques were implemented to capture and document the events surrounding a vehicle rollover. These devices and techniques are presented and compared with previous test methodology. In this case study, an instrumented 1996 GMC Jimmy SUV was towed to speed and then released. A steering controller steered the vehicle through maneuvers intended to result in rollover. The SUV experienced two non-rollover events before the vehicle finally rolled 1-1½ times.
2015-04-14
Technical Paper
2015-01-1461
Dietmar Otte
During most pedestrian-vehicle crashes the car front impacts the pedestrian and the whole body wraps around the front shape of the car. Meanwhile the windscreen is tested in NCAP conditions. The severity of injuries is influenced by car impact speed; type of vehicle; stiffness and shape of the vehicle; nature of the front (such as the bumper height, bonnet height and length, windscreen frame); age and height of the pedestrian; and standing position of the pedestrian relative to the vehicle front. The socalled Wrap Around Distance WAD is one of important measurement for the assessment of protection. For the study accidents with pedestrians and bicyclists are used for the analysis, how good is the WAD for injury prediction. GIDAS (German In-Depth-Accident-Study) collects accidents as representative sample of the German accident situation based on in-depth-investigation.
2015-04-14
Technical Paper
2015-01-1462
Seung Jun YANG
Euro-Ncap committee has been adopted overall impact star-grade system after 2009 and strengthening pedestrian protection cut-off score to obtain best impact-star grade until 2016. It is very difficult target to pass enhanced pedestrian cut-off score due to previous method. In this paper, I studied where is pedestrian weak area and why pedestrian injury is so high at that area based on our test result. I compared long-hood, 3 corner pop-up hood and pedestrian air-bag system. Finlly I suggest 3-corner rear-ward hood pop-up system is best method to meet our Impact new target in considering pedestrian protection ability, cost &weight.
2015-04-14
Technical Paper
2015-01-1463
In Hwang, Jisung Ryu, Jinho Kim, Jeahong Choi, Junho Lee
Injuries of occupants in a vehicle have been decreased considerably. However, efforts for protection of pedestrians are still insufficient and so as to satisfy enhanced regulation, pedestrian protection has been an important issue to get a high NCAP rating. These days, many advanced industries are striving for a better protection of pedestrians by using an active hood system. The active hood system is designed for reducing head injury of pedestrian. The most important part of an active hood system is sensor & ECU. In this paper we discuss the fiber optical sensor with membrane switches to detect pedestrians
2015-04-14
Technical Paper
2015-01-1465
Sho Nikaido, Shota Wada, Yasuhiro Matsui, Shoko Oikawa, Toshiya Hirose
1. Background and purpose There are various contributing factors to accidents of bicycles, it is considered that cyclists often do not observe the traffic regulation that requires cyclists to stop before a stop line at an intersection. As a countermeasure to this type of accident, cycling assist systems that activate a warning system for cyclists have been researched and developed. This assist system warns the cyclist about the danger of a collision. Such an assist system needs to provide a warning with appropriate timing. It is necessary to clarify cycling characteristics in developing a countermeasure for traffic accidents at an intersection without signals. The findings of this study can be used for the future construction of an assist system that will encourage cyclists to observe traffic regulations.
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