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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
2015-01-1443
Morteza Seidi, Marzieh Hajiaghamemar, James Ferguson, Vincent Caccese
Falls in the elderly population is an important concern to individuals, family, friends, and in the healthcare industry. When the head is left unprotected, head impact levels can reach upwards of 500 g (gravitational acceleration), which is a level that can cause serious injury or death. A protective system for a fall injury needs to be designed with specific criteria in mind including energy protection level, thickness, stiffness, weight, and cost among others. The current study quantifies the performance of a protective head gear design for persons prone to falls. The main objective of this paper is to evaluate the injury mitigation of head protection gear made from a patented system of polyurethane honeycomb and dilatant materials. To that end, a twin wire fall system equipped with a drop arm that includes a Hybrid-III head/neck assembly was used.
2015-04-14
Technical Paper
2015-01-1440
Srinivas Gunti, Anindya Deb, Malhar Kumar MD
Human lumbar spine is one of the most commonly injured parts of the anatomy in vehicle accidents. Earlier studies have shown higher severity of lumbar spine injuries in occupants subjected to vehicle rollover crash. An understanding of its mechanical response is essential for developing accurate finite element models for studying Lumbar spinal injury patterns resulting from vehicle rollover crash. In the present work, experimental and numerical characterization of the elasto-plastic behaviour of human lumbar truncated vertebral unit (TVU) under quasi static and impact loading was studied. A truncated vertebral unit was prepared from lumbar spine of a donated male body and tested in a universal testing machine (UTM) for mechanical characterization under quasi static compressive loading conditions. Experiments were then conducted in a drop-weight impact testing device to investigate crash performance characteristics such as mean crush load and absorbed energy of the TVU.
2015-04-14
Technical Paper
2015-01-1438
Maria de Odriozola
Nowadays, the development of high performance passive safety systems is becoming more and more demanding in order to enhance the performance of the new vehicles that are being introduced in the automotive market. With this aim, a series of new generation dummies are being developed so as to dispose of anthropomorphic test devices that count with higher biofidelity levels than the dummies that have been used until now. For frontal impact, the NHTSA is currently developing the THOR Dummy with the objective to achieve a dummy with a high level of performance to enable the investigation and creation of improved restraint systems. By using the THOR dummy it is possible to study the movement of the 3D surface of the occupants’ chest and, in this way, to acquire much more information for the adequate design of restraint systems for frontal impact.
2015-04-14
Technical Paper
2015-01-1418
Shane Richardson, Nikola Josevski, Andreas Sandvik, Tandy Pok, Tia Lange Orton, Blake Winter, Xu Wang
Pedestrian throw distance can be used to evaluate vehicle impact speed for wrap or forward projection type pedestrian collisions. There have been multiple papers demonstrating relationships between the impact speed of a vehicle and the subsequent pedestrian throw distance. In the majority of instances the scenarios evaluated focused on the central width of the vehicle impacting the pedestrian. However based on investigated pedestrian collisions there is a depending on where and how the vehicle and pedestrian engaged with one another, the definition of the engagement can and does significantly influence the throw distance. PC-Crash was used to simulate multiple pedestrian impacts at multiple speeds and pedestrian throw distance impact speed contour plots were created. The pedestrian throw distance impact speed contour plots for a range of vehicle types and pedestrian sizes are presented.
2015-04-14
Technical Paper
2015-01-1450
Jeremy Daily, Andrew Kongs, Jose Corcega, James Johnson
The proper investigation of crashes involving commercial vehicles is critical for fairly assessing liability and damages, if they exist. In addition to traditional physics based approaches, the digital records stored within heavy vehicle electronic control modules (ECMs) are useful in determining the events leading to a crash. Traditional methods of extracting digital data use proprietary diagnostic and maintenance software and require a functioning ECM. However, some crashes induce damage that renders the ECM inoperable, even though it may still contain data. As such, the objective of this research is to examine the digital record in an ECM and understand its meaning. The research was performed on a Detroit Diesel DDEC V engine control module. The data extracted from the flash memory chips include: Last Stop Record, two Hard Brake events, and the Daily Engine Usage Log. The procedure of extracting and reading the memory chips is explained.
2015-04-14
Technical Paper
2015-01-1441
Yibing Shi, Guy Nusholtz
The method of assessing the similarity of a set of impact test signals has been the subject of several studies. The cumulative variance measure has been proposed and used in some studies; while the correlation-based assessment represents an alternative approach. 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 measure. 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 dependent of these.
2015-04-14
Technical Paper
2015-01-1437
Tony R. Laituri, Raed El-jawahri, Scott Henry, Kaye Sullivan
Various risk curves for head injury potential were assessed theoretically relative to field data. Specifically, two AIS2+ risk curves were studied: the HIC15-based risk curve from Mertz (1997) and the provisional, BRIC-based risk curve from Takhounts et al. (2013). These two risk curves were used to estimate attendant injury potential for belted drivers in full-engagement frontal crashes in the National Automotive Sampling System (NASS). The occupant responses pertaining to those crashes were estimated from representative math models, and the risk curves were used to convert event responses into event risks. The assessment was conducted from two perspectives: aggregate (0-56 kph) and a point-estimate (56 kph, barrier-like). Finally, the point-estimate assessment was supplemented by considering corresponding laboratory tests. The results from HIC15-based risk curve were understated, whereas the results from the BRIC-based risk curve were overstated.
2015-04-14
Technical Paper
2015-01-1415
Yasuhiro Matsui, Shoko Oikawa
The number of traffic deaths in Japan decreased over the past 20 years to 4373 in 2013. Among accident types of road-accident fatalities, only cyclist fatalities increased in number from 2012 to 2013, from 563 to 600, an increase of 7%. The Japanese government began assessing the safety performance of car bonnet tops in terms of pedestrian deaths in 2005, but there has been no effective regulation for cyclist protection in Japan. The implementation of countermeasures that reduce the severity of injuries and number of deaths in traffic accidents requires a detailed understanding of the features of cyclist injuries in vehicle-versus-cyclist accidents. The aim of this study is to clarify the circumstances in which cyclists are injured.
2015-01-14
Technical Paper
2015-26-0152
Alok Anand, Pratap Daphal, Pratyush Khare
Abstract The vehicle crash signature (here on referred as crash pulse) significantly affects occupant restraints system performance in frontal crash events. Restraints system optimization is usually undertaken in later phase of product development. This leads to sub-optimal configurations and performance, as no opportunity exists to tune vehicle structure and occupant package layouts. In concept phase of development, crash pulse characterization helps to map occupant package environment with available structure crush space and stiffness. The crash pulse slope, peaks, average values at discrete time intervals, can be tuned considering library of restraints parameters. This would help to derive an optimal occupant kinematics and occupant-restraints interaction in crash event. A case study has been explained in this paper to highlight the methodology.
2015-01-14
Technical Paper
2015-26-0172
Girikumar Kumaresh, Thomas Lich, Moennich Joerg
Abstract In the year of 2012 in India the total number of accidents with injuries is registered by Ministry of Road Transport and Highway with 490,383 out of which injured people are 509,667 and fatalities are 138,258 [1]. Nearly 17% of the fatalities are occupants of passenger cars which constitute the second highest contributor for fatal accidents in India [1]. In order to understand the root causes for car accidents in India, Bosch accident research carried out a study based on in-depth accidents collected in India. Apart from other accident contributing factors e.g. infrastructure the driver behaviour and his actions few milliseconds just prior to the crash is an extremely important and a key valuable data for the understanding of accident causation. Further on it supports also the development of modern automotive safety functions. Hence this research was undertaken to evaluate the benefit of the state-of-the art vehicle safety systems known as Antilock Braking System (ABS).
2015-01-14
Technical Paper
2015-26-0167
Thomas Lich, Girikumar Kumaresh, Joerg Moennich
Abstract Motorized two wheelers, also known as powered two wheelers (PTW) are the most common mode of transportation in India. Around one in four deaths that occurred on the roads in India in 2012 involved a motorcyclist, according to Ministry of Road Transport and Highways. This constitutes the highest contributor for fatal accidents in India [1]. The European Transport Safety Council (ETSC) analysis shows the risk of a motorcyclist having a fatal accident is 20 times greater than for a car driver travelling the same route [2]. An investigation conducted by Bosch looked at the accident database of Road Accident Sampling System for India (RASSI). This investigation revealed interesting facts about the Indian motorcycle accident situation, such as root causes of powered two wheeler collisions and riders behaviour including their braking patterns during the pre-crash phase of the accident.
2015-01-14
Technical Paper
2015-26-0162
Hasan M. Naqvi, Geetam Tiwari
Abstract Road accidents and persons killed in India have been reported to the tune of 4,90,383 and 1,38,258 respectively during 2012. On National Highways (NHs), major share of accidents (about 29%) and number of persons killed (35.3%) are observed out of total accidents. National Highways in India constitute about 2% of total road network (92,851 km) in India, but carries about 40% of traffic. 46% (42,829 km) of NHs in India comprises of two-lane and about 19% (17239 km) of NHs are single or intermediate-lane. Road accidents being multi-disciplinary in nature involves attention of multiple departments such as Highways Authority, Police, Motor Vehicles, Automobile Manufacturers, NGOs, etc. Owing to spurt in growth of motor vehicle population in India, road accidents are not reduced significantly despite improvement in NHs (widening of carriageway and riding quality).
2015-01-14
Technical Paper
2015-26-0209
Ludek Hyncik, Jan Spicka, Jaroslav Manas, Jan Vychytil
Abstract The paper contributes to the field of vehicle safety technology by the virtual approach using biomechanical virtual human body models. The goal of the paper is to exploit the previously developed scaling algorithm to create several virtual human models of a given age and body proportions and to assess the impact analysis using the sensitivity approach. Based on a validated reference model, the previously developed scaling algorithm develops virtual human body models for given height, mass, age and gender. Particular body segments are scaled based on the anthropometrical database concerning the body dimensions taking also percentiles into account. The body stiffness is driven by age dependent flexindex. Several virtual models of human bodies representing particular cadavers were generated via the automatic scaling algorithm. The frontal sled test response of three models was successfully compared to the available experimental data previously.
2014-11-01
Book
This title carries the papers developed for the 2014 Stapp Car Crash Conference, the premier forum for the presentation of research in impact biomechanics, human injury tolerance, and related fields, advancing the knowledge of land-vehicle crash injury protection. The conference provides an opportunity to participate in open discussion the causes and mechanisms of injury, experimental methods and tools for use in impact biomechanics research, and the development of new concepts for reducing injuries and fatalities in automobile crashes. The topics covered this year include: • Head/brain biomechanics • Thorax, spine, and pelvis biomechanics • Overlap/angled frontal crash testing and real-world performance • Pedestrian and cyclist injury factors and testing • Rollover and side-impact crashes and computational modeling
2014-10-07
Magazine
Outlook for autonomous driving includes cloud Connectivity with off-board data and services and among vehicles will be crucial in maintaining safety and security in future autonomous vehicles. The next wave of crash simulation As computing speed has improved and software itself has made significant speed and performance gains with each release, modeling tools are now quick enough to build high-quality, large, high-detail vehicle models in a very efficient manner. SAE 2014 Convergence preview Interest in advanced driver-assistance technologies is surging, with automotive engineers and decision makers at OEMs and suppliers working feverishly on the convenience vs. safety trade-off and other electronics-related challenges. Cooled EGR shows benefits for gasoline engines Exhaust gas recirculation systems now in use on diesel engines are used mainly to meet emissions regulations. In gasoline engines, they are an appealing way to meet ever more stringent fuel-economy standards
2014-09-30
Technical Paper
2014-01-2388
Jeffrey K. Ball, Mark Kittel, Trevor Buss, Greg Weiss
Abstract Trucking fleets are increasingly installing video event recorders in their vehicles. The video event recorder system is usually mounted near the vehicle's rear view mirror, and consists of two cameras: one looking forward and one looking towards the driver. The system also contains accelerometers that record lateral and longitudinal g-loading, and some may record vehicle speed (in mph) based on GPS positions. The unit constantly monitors vehicle acceleration and speed, and also records video. However, the recorded data is only stored when a preset acceleration threshold is met. The primary use of the system is to assist fleets with driver training and education, but the recorded data is also being used as a tool to reconstruct accidents. By integrating the accelerometer data, the vehicle speed and distance traveled during the event can be calculated.
2014-08-18
WIP Standard
J98
This SAE Standard is intended to be used as a guide for manufacturers and users of general purpose industrial machines to provide a reasonable degree of protection for personnel during normal operation and servicing. This document excludes skid steers which are covered by SAE J1388. Avoidance of accidents also depends upon the care exercised by such persons (see SAE J153). Inclusion of this standard instate, federal, or any laws or regulations where flexibility of revision is lacking is discouraged.
2014-07-09
Standard
J1001_201407
The guidelines for operator and bystander protection in this recommended practice apply to towed, semimounted or mounted flail mowers and flail power rakes when powered by a propelling tractor or machine of at least 15 kw (20 hp), intended for marketing as industrial mowing equipment and designed for cutting grass and other growth in public use areas such as parks, cemeteries and along roadways and highways. The use of the word "industrial" is not to be confused with "in-plant industrial equipment". This document does not apply to: 1. Turf care equipment primarily designed for personal use, consumption or enjoyment of a consumer in or around a permanent or temporary household or residence. 2. Machines designed primarily for agricultural purposes but which may be used for industrial use. 3. Self powered or self propelled mowers or mowing machines.
2014-07-09
Standard
J232_201407
This SAE Standard establishes performance criteria for towed, semi-mounted, or mounted and arm type rotary mowers with one or more blade assemblies of 77.5 cm blade tip circle diameter or over, mounted on a propelling tractor or machine of at least 15 kW, intended for marketing as industrial mowing equipment and designed for cutting grass and other growth in public use areas such as parks, cemeteries, and along roadways and highways. The use of the word “industrial” is not to be confused with “in-plant industrial equipment.” This document does not apply to: a. Turf care equipment primarily designed for personal use, consumption, or enjoyment of a consumer in or around a permanent or temporary household or residence. b. Equipment designed primarily for agricultural purposes but which may be used for industrial use. c. Self-powered or self-propelled mowers or mowing machines.
2014-05-07
Technical Paper
2014-36-0025
Frederico A. A. Barbieri, Vinicius de Almeida Lima, Leandro Garbin, Joel Boaretto
Abstract Brazil presents a very diverse road and traffic conditions and due to several factors the number of truck accidents is very high. Inside truck accidents group, the one that causes the highest number of losses and fatalities is the rollover crash and understanding rollover dynamics is very important to prevent such events. The diversity of cargo vehicles arrangements requires a detailed study regarding the dynamic behavior these vehicle combinations in order to increase operation safety. The same tractor unit can be used with different types and numbers of trailers and/or semi-trailers, each one with different suspension configurations. These truck combinations have distinct dynamic performances that need evaluation. In this sense, this work presents a first phase study on the dynamic behavior of different types of cargo vehicle configuration. A 6×2 tractor is combined with a two distinct grain semi-trailer with different types of suspension: pneumatic and leaf spring.
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
2014-01-0811
Horst Lanzerath, Niels Pasligh
Abstract Structural adhesives are widely used across the automotive industry for several reasons like scale-up of structural performance and enabling multi-material and lightweight designs. Development engineers know in general about the effects of adding adhesive to a spot-welded structure, but they want to quantify the benefit of adding adhesives on weight reduction or structural performance. A very efficient way is to do that by applying analytical tools. But, in most of the relevant non-linear load cases the classical lightweight theory can only help to get a basic understanding of the mechanics. For more complex load cases like full car crash simulations, the Finite Element Method (FEM) with explicit time integration is being applied to the vehicle development process. In order to understand the benefit of adding adhesives to a body structure upfront, new FEM simulation tools need to be established, which must be predictive and efficient.
2014-04-01
Technical Paper
2014-01-0569
Ishika Zonina Towfic, Jennifer Johrendt
Abstract The development of a collision severity model can serve as an important tool in understanding the requirements for devising countermeasures to improve occupant safety and traffic safety. Collision type, weather conditions, and driver intoxication are some of the factors that may influence motor vehicle collisions. The objective of this study is to use artificial neural networks (ANNs) to identify the major determinants or contributors to fatal collisions based on various driver, vehicle, and environment characteristics obtained from collision data from Transport Canada. The developed model will have the capability to predict similar collision outcomes based on the variables analyzed in this study. A multilayer perceptron (MLP) neural network model with feed-forward back-propagation architecture is used to develop a generalized model for predicting collision severity.
2014-04-01
Technical Paper
2014-01-0961
Alan R. Wedgewood, Patrick Granowicz, Zhenyu Zhang
Abstract Materials used in automotive components play a key role in providing crash safety to passengers and pedestrians. DuPont's lightweight hybrid material technology, which combines injection molded fiber reinforced plastics with drape molded woven composite materials, provides safety engineers with stiff energy absorbing alternatives. In an effort to validate the hybrid material's crash performance while avoiding expensive crash testing, numerical tools and methodologies are applied in evaluation of a hybrid composite test beam. Multi-scale material models capturing nonlinear strain-rate dependency, anisotropic characteristics, and failure criteria, are calibrated on a fiber reinforced plastic and a woven fabric. The fiber orientation and warp/weft angles were extracted from injection and drape molding simulation.
2014-04-01
Technical Paper
2014-01-0397
Pit Schwanitz, Sebastian Werner, Johannes Zerbe, Dietmar Göhlich
Abstract A new methodology for crash sensitive vehicle structures has been developed to be used during the early stage of the Product Development Process (PDP). By frontloading significant and simplified CAE simulations and the use of stochastic optimization methods in conjunction with highly parametric CAD models, new concepts can be quickly identified and evaluated based on reliable product insight. Vehicle crashboxes have been chosen for verification of the methodology. An analysis of different but comparable vehicles showed a large variety of designs although they all absorb the energy of low speed crashes within a velocity of up to 15km/h. A powerful optimization model with a parametric geometry engine, a crash-solver and suitable optimization software, used within a batch process, has been established. The optimal results for one particular crashbox concept are presented to demonstrate the methodology and the benefit of the approach.
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.
2014-04-01
Technical Paper
2014-01-0477
Nathan A. Rose, Neal Carter
Abstract In a 2012 paper, Brach, Brach, and Louderback (BBL) investigated the uncertainty that arises in calculating the change in velocity and crush energy with the use of the CRASH3 equations (2012-01-0608). They concluded that the uncertainty in these values caused by variations in the stiffness coefficients significantly outweighed the uncertainty caused by variations in the crush measurements. This paper presents a revised analysis of the data that BBL analyzed and further assesses the level of uncertainty that arises in CRASH3 calculations. While the findings of this study do not invalidate BBL's ultimate conclusion, the methodology utilized in this paper incorporated two changes to BBL's methodology. First, in analyzing the crash test data for several vehicles, a systematic error that is sometimes present in the reported crush measurements was accounted for and corrected.
2014-04-01
Technical Paper
2014-01-0464
Nathan A. Rose, Neal Carter, David Pentecost
Abstract PC-Crash™, a widely used crash analysis software package, incorporates the capability for modeling non-constant vehicle acceleration, where the acceleration rate varies with speed, weight, engine power, the degree of throttle application, and the roadway slope. The research reported here offers a validation of this capability, demonstrating that PC-Crash can be used to realistically model the build-up of a vehicle's speed under maximal acceleration. In the research reported here, PC-Crash 9.0 was used to model the full-throttle acceleration capabilities of three vehicles with automatic transmissions - a 2006 Ford Crown Victoria Police Interceptor (CVPI), a 2000 Cadillac DeVille DTS, and a 2003 Ford F150. For each vehicle, geometric dimensions, inertial properties, and engine/drivetrain parameters were obtained from a combination of manufacturer specifications, calculations, inspections of exemplar vehicles and full-scale vehicle testing.
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