Criteria

Text:
Topic:
Display:

Results

Viewing 61 to 90 of 11101
2017-03-28
Technical Paper
2017-01-1307
Puneet Bahri, Praveen Balaj Balakrishnan, Ravi Purnoo Munuswamy
Abstract Automotive industries are emphasizing more and more on occupant safety these days, due to an increase in awareness and demand to achieve high safety standards. They are dependent on simulation tools to predict the performance of subsystems more accurately. The challenges being encountered are designs which are getting more complex and limitations in incorporating all real-life scenarios, such as to include all manufacturing considerations like forming and welding effects. Latest versions of solvers are slowly introducing new options to include these actual scenarios. Ls-Dyna is one of the explicit solvers to introduce these possibilities. The process of including stamping details into crash simulation is already being performed in the automotive industry. However, for seatbelt pull analysis, this has not been explored much.
2017-03-28
Technical Paper
2017-01-1417
Enrique Bonugli, Richard Watson, Mark Freund, Jeffrey Wirth
Abstract This paper reports on seventy additional tests conducted using a mechanical device described by Bonugli et al. [4]. The method utilized quasi-static loading of bumper systems and other vehicle components to measure their force-deflection properties. Corridors on the force-deflection plots, for various vehicle combinations, were determined in order to define the system stiffness of the combined vehicle components. Loading path and peak force measurements can then be used to evaluate the impact severity for low speed collisions in terms of delta-v and acceleration. The additional tests refine the stiffness corridors, previously published, which cover a wide range of vehicle types and impact configurations. The compression phase of a low speed collision can be modeled as a spring that is defined by the force-deflection corridors. This is followed by a linear rebound phase based on published restitution values [1,5].
2017-03-28
Technical Paper
2017-01-1368
Jeffrey Aaron Suway, Steven Suway
Abstract Mapping the luminance values of a visual scene is of broad interest to accident reconstructionists, human factors professionals, and lighting experts. Such mappings are useful for a variety of purposes, including determining the effectiveness and appropriateness of lighting installations, and performing visibility analyses for accident case studies. One of the most common methods for mapping luminance is to use a spot type luminance meter. This requires individual measurements of all objects of interest and can be extremely time consuming. Luminance cameras can also be used to create a luminance map. While luminance cameras will map a scene’s luminance values more quickly than a spot luminance meter, commercially available luminance cameras typically require long capture times during low illuminance (up to 30 seconds). Previous work has shown that pixel intensity captured by consumer-grade digital still cameras can be calibrated to measure luminance.
2017-03-28
Technical Paper
2017-01-1439
John C. Steiner, Christopher Armstrong, Tyler Kress, Tom Walli, Ralph J. Gallagher, Justin Ngo, Andres Silva
Abstract The use of the United States’ Global Positioning System (GPS) to assist with the management of large commercial fleets using telematics is becoming commonplace. Telematics generally refers to the use of wireless devices to transmit data in real time back to an organization. When tied to the GPS system telematics can be used to track fleet vehicle movements, and other parameters. GPS tracking can assist in developing more efficient and safe operations by refining and streamlining routing and operations. GPS based fleet telematics data is also useful for reducing unnecessary engine idle times and minimizing fuel consumption. Driver performance and policy adherence can be monitored, for example by transmitting data regarding seatbelt usage when there is vehicle movement. Despite the advantages for fleet management, there are limitations in the logged data for position and speed that may affect the utility of the system for analysis and reconstruction of traffic collisions.
2017-03-28
Technical Paper
2017-01-1459
HangMook Kim, Jae Kyu Lee, Jin Sang CHUNG
Abstract During a new vehicle development process, there are several requirements for side impact test that should be confirmed. One of the requirements is the prevention of door opening during side impact test. Even though there are many causes for door opening problem, this study deals with inertia effect by impact energy. Until now, there have been two classical methods to prevent car door from opening in side impact. One is the increment of the inertia resistance by increasing the mass of the balance weight and the spring force. The other is the application of the blocking lever. Unfortunately, in spite of our efforts, the door opening problem occurs occasionally. Therefore, to improve the problem fundamentally, this paper proposes a new blocking lever mechanism that work similar to ball-point pen structure. The proposed mechanism fixes the blocking lever when the opening directional inertia force is applied to the door outside handle during side crash.
2017-03-28
Journal Article
2017-01-1463
Xianping Du, Feng Zhu, Clifford C. Chou
Abstract A new design methodology based on data mining theory has been proposed and used in the vehicle crashworthiness design. The method allows exploring the big dataset of crash simulations to discover the underlying complicated relationships between response and design variables, and derive design rules based on the structural response to make decisions towards the component design. An S-shaped beam is used as an example to demonstrate the performance of this method. A large amount of simulations are conducted and the results form a big dataset. The dataset is then mined to build a decision tree. Based on the decision tree, the interrelationship among the geometric design variables are revealed, and then the design rules are derived to produce the design cases with good energy absorbing capacity. The accuracy of this method is verified by comparing the data mining model prediction and simulation data.
2017-03-28
Technical Paper
2017-01-1473
Ling Zheng, Yinan Gao, Zhenfei Zhan, Yinong Li
Abstract Several surrogate models such as response surface model and radial basis function and Kriging models are developed to speed the optimization design of vehicle body and improve the vehicle crashworthiness. The error analysis is used to investigate the accuracy of different surrogate models. Furthermore, the Kriging model is used to fit the model of B-pillar acceleration and foot well intrusion. The response surface model is used to fit the model of the entire vehicle mass. These models are further used to calculate the acceleration response in B-pillar, foot well intrusion and vehicle mass instead of the finite element model in the optimization design of vehicle crashworthiness. A multi-objective optimization problem is formulated in order to improve vehicle safety performance and keep its light weight. The particle swarm method is used to solve the proposed multi-objective optimization problem.
2017-03-28
Technical Paper
2017-01-0031
Mohamed Benmimoun
Abstract In the last years various advanced driver assistance systems (ADAS) have been introduced on the market. More highly advanced functions up to automated driving functions are currently under research. By means of these functions partly automated driving in specific situations is already or will be realized soon, e.g. traffic jam assist. Besides the technical challenges to develop such automated driving functions for complex situations, e.g. construction or intersection areas, new approaches for the evaluation of these functions under different driving conditions are necessary, in order to assess the benefits and identify potential weaknesses. Classical approaches for evaluation and market sign off will require an extensive testing, which results in high costs and time demands. Therefore the classical approaches are hardly feasible taking into account higher levels of support and automation. Today the final sign-off requires a high amount of real world tests.
2017-03-28
Technical Paper
2017-01-1418
Wesley D. Grimes, Thomas Vadnais, Gregory A. Wilcoxson
Abstract The time/distance relationship for a heavy truck accelerating from a stop is often needed to accurately assess the events leading up to a collision. Several series of tests were conducted to document the low speed acceleration performance of a 2016 Kenworth T680 truck tractor equipped with a ten-speed overdrive automated manual transmission in Auto Mode. Throughout the testing, the driver never manually shifted gears. This testing included three trailer load configurations and two different acceleration rates. Data were gathered with a VBOX and the Cummins INSITE software.
2017-03-28
Technical Paper
2017-01-1354
Timothy Morse, Michael Cundy, Harri Kytomaa
Abstract One potential fire ignition source in a motor vehicle is the hot surfaces on the engine exhaust system. These hot surfaces can come into contact with combustible and flammable liquids (such as engine oil, transmission fluid, brake fluid, gasoline, or Diesel fuel) due to a fluid leak, or during a vehicle collision. If the surface temperature is higher than the hot surface ignition temperature of the combustible or flammable liquid in a given geometry, a fire can potentially ignite and propagate. In addition to automotive fluids, another potential fuel in post-collision vehicle fires is grass, leaves, or other vegetation. Studies of hot surface ignition of dried vegetation have found that ignition depends on the type of vegetation, surface temperature, duration of contact, and ambient conditions such as temperature and wind speed. Ignition can occur at surface temperatures as low as 300 °C, if the vegetation is in contact with the surface for 10 minutes or longer.
2017-03-28
Technical Paper
2017-01-1353
Michael G. Leffert
Abstract This paper compares the material consumption and fire patterns which developed on four nearly identical compact sedans when each was burned for exactly the same amount of time, but with different wind speed and direction during the burns. This paper will also compare the effects of environmental exposure to the fire patterns on the vehicles. The burn demonstrations were completed at an outdoor facility in southeast Michigan on four late model compact sedans. The wind direction was controlled by placing the subject vehicle with either the front facing into the wind, or rear facing into the wind. Two of the burns were conducted when the average observed wind speed was 5-6kph and two of the burns were conducted at an average observed wind speed of 19kph.
2017-03-28
Technical Paper
2017-01-1414
William Bortles, David Hessel, William Neale
Abstract When a vehicle with protruding wheel studs makes contact with another vehicle or object in a sideswipe configuration, the tire sidewall, rim and wheel studs of that vehicle can deposit distinct geometrical damage patterns onto the surfaces it contacts. Prior research has demonstrated how relative speeds between the two vehicles or surfaces can be calculated through analysis of the distinct contact patterns. This paper presents a methodology for performing this analysis by visually modeling the interaction between wheel studs and various surfaces, and presents a method for automating the calculations of relative speed between vehicles. This methodology also augments prior research by demonstrating how the visual modeling and simulation of the wheel stud contact can extend to almost any surface interaction that may not have any previous prior published tests, or test methods that would be difficult to setup in real life.
2017-03-28
Journal Article
2017-01-1352
David Gardiner
Abstract This paper presents an experimental study of the vapour space flammability of Fuel Ethanol (a high-ethanol fuel for Flexible Fuel Vehicles, commonly known as “E85”) and gasoline containing up to 10% ethanol (commonly known as “E10”). The seasonal minimum vapour pressure limits in specifications for automotive spark ignition fuels are intended, in part, to minimize the formation of flammable mixtures in the headspace of vehicle fuel tanks. This is particularly important at subzero temperatures, where the headspace mixture may not be rich enough to prevent combustion in the presence of an ignition source such as a faulty electrical fuel pump. In the current study, the upper temperature limits of flammability were measured for field samples of “E85” and “E10”, and a series of laboratory-prepared blends of denatured ethanol, Before Oxygenate Blending (BOB) gasoline, and n-butane.
2017-03-28
Journal Article
2017-01-1351
Vamshi Korivi, Steven McCormick, Steven Hodges
Abstract The US Army Tank Automotive Research, Development and Engineering Center (TARDEC) has developed a unique physics based modeling & simulation (M&S) capability using Computational Fluid Dynamics (CFD) techniques to optimize automatic fire extinguishing system (AFES) designs and complement vehicle testing for both occupied and unoccupied spaces of military ground vehicles. The modeling techniques developed are based on reduced global kinetics for computational efficiency and are applicable to fire suppressants that are being used in Army vehicles namely, bromotrifluoromethane (Halon 1301), heptafluoropropane (HFC-227ea, trade name FM200), sodium-bicarbonate (SBC) powder, water + potassium acetate mixture, and pentafluoroethane (HFC-125, trade name, FE-25). These CFD simulations are performed using High Performance Computers (HPC) that enable the Army to assess AFES designs in a virtual world at far less cost than physical-fire tests.
2017-03-28
Technical Paper
2017-01-1675
Genís Mensa, Núria Parera, Alba Fornells
Abstract Nowadays, the use of high-speed digital cameras to acquire relevant information is a standard for all laboratories and facilities working in passive safety crash testing. The recorded information from the cameras is used to develop and improve the design of vehicles in order to make them safer. Measurements such as velocities, accelerations and distances are computed from high-speed images captured during the tests and represent remarkable data for the post-crash analysis. Therefore, having the exact same position of the cameras is a key factor to be able to compare all the values that are extracted from the images of the tests carried out within a long-term passive safety project. However, since working with several customers involves a large amount of different cars and tests, crash facilities have to readapt for every test mode making it difficult for them to reproduce the correct and precise position of the high-speed cameras throughout the same project.
2017-03-28
Technical Paper
2017-01-0113
Vaclav Jirovsky
Abstract Today's vehicles are being more often equipped with systems, which are autonomously influencing the vehicle behavior. More systems of the kind and even fully autonomous vehicles in regular traffic are expected by OEMs in Europe around year 2025. Driving is highly multitasking activity and human errors emerge in situations, when he is unable to process and understand the essential amount of information. Future autonomous systems very often rely on some type of inter-vehicular communication. This shall provide the vehicle with higher amount of information, than driver uses in his decision making process. Therefore, currently used 1-D quantity TTC (time-to-collision) will become inadequate. Regardless the vehicle is driven by human or robot, it’s always necessary to know, whether and which reaction is necessary to perform. Adaptable autonomous vehicle systems will need to analyze the driver’s situation awareness level.
2017-03-28
Technical Paper
2017-01-1380
Richard Young
Abstract Dingus and colleagues recently estimated the crash odds ratios (ORs) for secondary tasks in the Strategic Highway Research Program Phase 2 (SHRP 2) naturalistic driving study. Their OR estimate for hand-held cell phone conversation (Talk) was 2.2, with a 95% confidence interval (CI) from 1.6 to 3.1. This Talk OR estimate is above 1, contrary to previous estimates below 1. A replication discovered two upward biases in their analysis methods. First, for video clips with exposure to a particular secondary task, Dingus and colleagues selected clips not only with exposure to that task, but often with concurrent exposure to other secondary tasks. However, for video clips without exposure to that task, Dingus and colleagues selected video clips without other secondary tasks. Hence, the OR estimate was elevated simply because of an imbalanced selection of video clips, not because of risk from a particular secondary task.
2017-03-28
Technical Paper
2017-01-1370
Hiroyuki Hara, Masaaki Kawauchi, Masayuki Katayama, Noriyuki Iwamori
Abstract Driving is an action that depends strongly on visual information. For displays in the cockpit, a combination of “ease of viewing” to inform the driver of danger early and “annoyance reduction” to avoid drops in the driver’s perception is needed. In this study, we tried to capture “ease of viewing” and “annoyance” in one fixed-quantity indicator. We took up a Camera Monitor System (CMS) as the subject and analyzed the effect that annoyance with the display used in CMSs has on driving behavior. Based on our analysis, we hypothesize that evaluating carelessness in viewing behavior is related evaluating to annoyance. Next, we chose a Detection Response Task (DRT) technique as a method to evaluate driving behavior influenced by this annoyance.
2017-03-28
Technical Paper
2017-01-1366
Jeffrey Muttart, Swaroop Dinakar, Jeffrey Suway, Michael Kuzel, Timothy Maloney, Wayne Biever, Toby Terpstra, Tilo Voitel, David Cavanaugh, T.J. Harms
Abstract Collision statistics show that more than half of all pedestrian fatalities caused by vehicles occur at night. The recognition of objects at night is a crucial component in driver responses and in preventing nighttime pedestrian accidents. To investigate the root cause of this fact pattern, Richard Blackwell conducted a series of experiments in the 1950s through 1970s to evaluate whether restricted viewing time can be used as a surrogate for the imperfect information available to drivers at night. The authors build on these findings and incorporate the responses of drivers to objects in the road at night found in the SHRP-2 naturalistic database. A closed road outdoor study and an indoor study were conducted using an automatic shutter system to limit observation time to approximately ¼ of a second. Results from these limited exposure time studies showed a positive correlation to naturalistic responses, providing a validation of the time-limited exposure technique.
2017-03-28
Technical Paper
2017-01-1423
Alan F. Asay, Christopher D. Armstrong, Bradley Higgins, John Steiner
Abstract The rear override crash behavior of full-size and light duty pickup trucks was examined. A series of ten full-scale, front and rear override impact crash tests were conducted involving four full-size pickup trucks, two light duty pickup trucks, and one sport utility vehicle (SUV). The tests were conducted utilizing a fabricated steel rigid barrier mounted on the front of the Massive Moving Barrier (MMB) test device with full overlap of the test vehicle. Crush ranged from 25.0 to 77.9 inches for impact speeds of 21.7 to 36.0 mph. These override tests on pickups were conducted to provide more basis in an area that is underrepresented in the literature. Each test was documented and measured prior to, and following, the crash test. The stiffness parameters were calculated and presented using constant stiffness, force saturation, and the power law damage models.
2017-03-28
Technical Paper
2017-01-1458
Tack Lam, B. Johan Ivarsson
Abstract Disc herniations in the spine are commonly associated with degenerative changes, and the prevalence increases with increasing age. With increasing number of older people on U.S. roads, we can expect an increase in clinical findings of disc herniations in occupants involved in rear impacts. Whether these findings suggest a causal relationship is the subject of this study. We examined the reported occurrence of all spine injuries in the National Automotive Sampling System - Crashworthiness Data System (NASS-CDS) database from 1993 to 2014. There were over 4,000 occupants that fit the inclusion criteria. The findings in this study showed that, in the weighted data of 2.9 million occupants, the most common spine injury is an acute muscle strain of the neck, followed by strain of the low back. The delta-V of a rear impact is a reliable indicator of the rate of acute cervical strain in occupants exposed to such impacts.
2017-03-28
Technical Paper
2017-01-1424
Mark Fabbroni, Jennifer Rovt, Mark Paquette
Abstract Collision reconstruction often involves calculations and computer simulations, which require an estimation of the weights of the involved vehicles. Although weight data is readily available for automobiles and light trucks, there is limited data for heavy vehicles, such as tractor-semitrailers, straight trucks, and the wide variety of trailers and combinations that may be encountered on North American roads. Although manufacturers always provide the gross vehicle weight ratings (GVWR) for these vehicles, tare weights are often more difficult to find, and in-service loading levels are often unknown. The resulting large uncertainty in the weight of a given truck can often affect reconstruction results. In Canada, the Ministry of Transportation of Ontario conducted a Commercial Vehicle Survey in 2012 that consisted of weight sampling over 45,000 heavy vehicles of various configurations.
2017-03-28
Journal Article
2017-01-1416
B. Nicholas Ault, Daniel E. Toomey
Abstract Reconstruction of passenger vehicle accidents involving side impacts with narrow objects has traditionally been approached using side stiffness coefficients derived from moveable deformable barrier tests or regression analysis using the maximum crush in available lateral pole impact testing while accounting for vehicle test weight. Current Lateral Impact New Car Assessment Program (LINCAP) testing includes 20 mph oblique lateral pole impacts. This test program often incorporates an instrumented pole so the force between the vehicle and pole at several elevations along the vehicle - pole interface is measured. Force-Displacement (F-D) characteristics of vehicle structures were determined using the measured impact force and calculated vehicle displacement from on-board vehicle instrumentation. The absorbed vehicle energy was calculated from the F-D curves and related to the closing speed between the vehicle and the pole by the vehicle weight.
2017-03-28
Technical Paper
2017-01-0059
Barbaros Serter, Christian Beul, Manuela Lang, Wiebke Schmidt
Abstract Today, highly automated driving is paving the road for full autonomy. Highly automated vehicles can monitor the environment and make decisions more accurately and faster than humans to create safer driving conditions while ultimately achieving full automation to relieve the driver completely from participating in driving. As much as this transition from advanced driving assistance systems to fully automated driving will create frontiers for re-designing the in-vehicle experience for customers, it will continue to pose significant challenges for the industry as it did in the past and does so today. As we transfer more responsibility, functionality and control from human to machine, technologies become more complex, less transparent and making constant safe-guarding a challenge. With automation, potential misuse and insufficient system safety design are important factors that can cause fatal accidents, such as in TESLA autopilot incident.
2017-03-28
Technical Paper
2017-01-1272
Nick Parson, Jerome Fourmann, Jean-Francois Beland
Abstract One of the main applications for aluminum extrusions in the automotive sector is crash structures including crash rails, crash cans, bumpers and structural body components. The objective is usually to optimize the energy absorption capability for a given structure weight. The ability to extrude thin wall multi-void extrusions contributes to this goal. However, the alloy used also plays a significant role in terms of the ability to produce the required geometry, strength - which to a large extent controls the energy absorption capability and the “ductility” or fracture behavior which controls the strain that can be applied locally during crush deformation before cracking. This paper describes results of a test program to examine the crush behavior of a range of alloys typically supplied for automotive applications as a function of processing parameters including artificial ageing and quench rate.
2017-03-28
Technical Paper
2017-01-1412
Christopher H. Goddard, David Price
Abstract Various mechanisms have been used to drive speedometers and other instrument gauges. This paper reviews the mechanisms used; in particular investigates the ability of stepper motors which have become the most common instrument motor in the last decade to freeze at the apparent reading prior to impact. Stepper motors require power to drive the needle to any indicated position, including having to return it to zero. Hence if power to the instrument is lost as a result of a collision, there is no power to move the needle and it should be left at the reading shown at the moment the power was lost. However, not all stepper motor instruments are the same and before accepting the reading, a number of criteria need to be considered to give a level of confidence in the result. As part of recent ITAI (Institute of Traffic Accident Investigators) crash test events in the UK, a number of instrument clusters were installed in vehicles to simulate both frontal and side impacts.
2017-03-28
Technical Paper
2017-01-1427
Daniel Koch, Gray Beauchamp, David Pentecost
Abstract Tire disablement events can cause a drag force that slows a vehicle. In this study, the magnitude of the deceleration was measured for different phases of 29 high speed tire tread separation and air loss tests. These deceleration rates can assist in reconstructing the speed of a vehicle involved in an accident following a tire disablement.
2017-03-28
Journal Article
2017-01-1432
Tadasuke Katsuhara, Yoshiki Takahira, Shigeki Hayashi, Yuichi Kitagawa, Tsuyoshi Yasuki
Abstract This study used finite element (FE) simulations to analyze the injury mechanisms of driver spine fracture during frontal crashes in the World Endurance Championship (WEC) series and possible countermeasures are suggested to help reduce spine fracture risk. This FE model incorporated the Total Human Model for Safety (THUMS) scaled to a driver, a model of the detailed racecar cockpit and a model of the seat/restraint systems. A frontal impact deceleration pulse was applied to the cockpit model. In the simulation, the driver chest moved forward under the shoulder belt and the pelvis was restrained by the crotch belt and the leg hump. The simulation predicted spine fracture at T11 and T12. It was found that a combination of axial compression force and bending moment at the spine caused the fractures. The axial compression force and bending moment were generated by the shoulder belt down force as the driver’s chest moved forward.
2017-03-28
Technical Paper
2017-01-1457
Jingwen Hu, Nichole Ritchie Orton, Rebekah Gruber, Ryan Hoover, Kevin Tribbett, Jonathan Rupp, Dave Clark, Risa Scherer, Matthew Reed
Abstract Among all the vehicle rollover test procedures, the SAE J2114 dolly rollover test is the most widely used. However, it requires the test vehicle to be seated on a dolly with a 23° initial angle, which makes it difficult to test a vehicle over 5,000 kg without a dolly design change, and repeatability is often a concern. In the current study, we developed and implemented a new dynamic rollover test methodology that can be used for evaluating crashworthiness and occupant protection without requiring an initial vehicle angle. To do that, a custom cart was designed to carry the test vehicle laterally down a track. The cart incorporates two ramps under the testing vehicle’s trailing-side tires. In a test, the cart with the vehicle travels at the desired test speed and is stopped by a track-mounted curb.
2017-03-28
Technical Paper
2017-01-1399
Bin Wu, Xichan Zhu, Jianping Shen, Xuejun Cang, Lin li
Abstract A driver steering model for emergency lane change based on the China naturalistic driving data is proposed in this paper. The steering characteristic of three phases is analyzed. Using the steering primitive fitting by Gaussian function, the steering behaviors in collision avoidance and lateral movement phases can be described, and the stabilization steering principle of yaw rate null is found. Based on the steering characteristic, the near and far aim point used in steering phases is analyzed. Using the near and far aim point correction model, a driver steering model for emergency lane change is established. The research results show that the driver emergency steering model proposed in this paper performs well when explaining realistic steering behavior, and this model can be used in developing the ADAS system.
Viewing 61 to 90 of 11101