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Viewing 61 to 90 of 17297
2017-03-28
Technical Paper
2017-01-1393
Georges Beurier, Michelle Cardoso, Xuguang Wang
Abstract A new experimental seat was designed to investigate sitting biomechanics. Previous literature suggested links between sitting discomfort and shear force, however, research on this topic is limited. The evaluation of sitting discomfort derived from past research has been primarily associated with seat pressure distribution. The key innovative feature of the experimental seat is not only pressure distribution evaluation but shear forces as well. The seat pan of the experimental seat compromises of a matrix of 52 cylinders, each equipped with a tri-axial force sensor, enabling us to measure both normal and tangential forces. The position of each cylinder is also adjustable permitting a uniform pressure distribution underneath the soft tissue of the buttocks and thighs. Backrest, armrests, seat pan and flooring are highly adjustable and equipped with forces sensors to measure contact forces.
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
2017-01-1422
Toby Terpstra, Seth Miller, Alireza Hashemian
Abstract Photogrammetry and the accuracy of a photogrammetric solution is reliant on the quality of photographs and the accuracy of pixel location within the photographs. A photograph with lens distortion can create inaccuracies within a photogrammetric solution. Due to the curved nature of a camera’s lens(s), the light coming through the lens and onto the image sensor can have varying degrees of distortion. There are commercially available software titles that rely on a library of known cameras, lenses, and configurations for removing lens distortion. However, to use these software titles the camera manufacturer, model, lens and focal length must be known. This paper presents two methodologies for removing lens distortion when camera and lens specific information is not available. The first methodology uses linear objects within the photograph to determine the amount of lens distortion present. This method will be referred to as the straight-line method.
2017-03-28
Journal Article
2017-01-1415
John D. Struble, Donald E. Struble
Abstract Crash tests of vehicles by striking deformable barriers are specified by Government programs such as FMVSS 214, FMVSS 301 and the Side Impact New Car Assessment Program (SINCAP). Such tests result in both crash partners absorbing crush energy and moving after separation. Compared with studying fixed rigid barrier crash tests, the analysis of the energy-absorbing behavior of the vehicle side (or rear) structure is much more involved. Described in this paper is a methodology by which analysts can use such crash tests to determine the side structure stiffness characteristics for the specific struck vehicle. Such vehicle-specific information allows the calculation of the crush energy for the particular side-struck vehicle during an actual collision – a key step in the reconstruction of that crash.
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
2017-01-1429
Sung Rae kim, Inju Lee, Hyung joo Kim
Abstract This paper aims to evaluate the biofidelity of a human body FE model with abdominal obesity in terms of submarining behavior prediction, during a frontal crash event. In our previous study, a subject-specific FE model scaled from the 50th percentile Global Human Body Model Consortium (GHBMC) human model to the average physique of three female post mortem human subjects (PMHSs) with abdominal obesity was developed and tested its biofidelity under lap belt loading conditions ([1]). In this study frontal crash sled simulations of the scaled human model have been performed, and the biofidelity of the model has been evaluated. Crash conditions were given from the previous study ([2]), and included five low-speed and three high-speed sled tests with and without anti-submarining device.
2017-03-28
Technical Paper
2017-01-1439
John C. Steiner, Christopher Armstrong, Tyler Kress
The use of the United States’ Global Positioning System (GPS) to assist with the management of large commercial fleets of vehicles is quickly becoming commonplace. The GPS system can be used to track fleet vehicles resulting in more efficient and safe operations by refining and streamlining routing and operations. GPS-based fleet telematics data is also valuable for reducing unnecessary engine idle times and minimizing fuel consumption. Driver performance and policy adherence can also be monitored, for example by transmitting data regarding seatbelt usage when there is vehicle movement. Despite its advantages for fleet management, there are performance limitations that affect the utility of the system for analysis and reconstruction of accidents. The U.S. Air Force, responsible for maintaining and operating the GPS space and control segments, publishes information about these limitations.
2017-03-28
Technical Paper
2017-01-1425
Brian Jones, Michael Calabro, Justin Brink, Scott Swinford
In minor inline rear-end accidents, vehicle damage is the primary tangible indicator of impact severity or vehicle change in velocity (ΔV). A technique for calculating change in velocity based on vehicle damage for collinear impacts involves application of the Momentum Energy Restitution (MER) method. Offset inline minor rear-end impact testing, wherein minimal vehicle bumper or contact surface engagement occurs, has not been readily published to date. Thus, instrumented offset inline rear-end impacts were performed utilizing a 1997 Ford F-150 Pickup, 1996 Kia Sephia, and 1995 Chrysler LeBaron GTC to determine if the MER method can accurately calculate a vehicle’s ΔV when collinear contact does not occur. Vehicle engagement involved 5.1 cm to 76.2 cm of overlap with impact speeds ranging between 0.7 m/s and 4 m/s.
2017-03-28
Journal Article
2017-01-1472
Niels Pasligh, Robert Schilling, Marian Bulla
Abstract Rivets, especially self-piercing rivets (SPR), are a primary joining technology used in aluminum bodied vehicles. SPR are mechanical joining elements used to connect sheets to create a body in white (BiW) structure. To ensure the structural performance of a vehicle in crash load cases it is necessary to describe physical occurring failure modes under overloading conditions in simulations. One failure mode which needs to be predicted precisely by a crash simulation is joint separation. Within crash simulations a detailed analysis of a SPR joint would require a very high computational effort. The conflict between a detailed SPR joint and a macroscopic vehicle model needs to be solved by developing an approach that can handle an accurate macroscopic prediction of SPR behavior with a defined strength level with less computational effort. One approach is using a cohesive material model for a SPR connection.
2017-03-28
Technical Paper
2017-01-1468
Do Hoi KIm
Previous work identified a relationship between vehicle drop and dummy injury under the high-speed frontal impact condition [1]. The results showed that vehicle drop greater than 60mm made the dummy injury worse. Moreover, that work identified the front side member as the crucial part affecting the vehicle drop. In this study, the body structure mechanism was studied to reduce vehicle drop by controlling the front side member, shotgun, and A-pillar. By analyzing full vehicles, it was recognized that the arch shape of the front side member was very important. Furthermore, if the top of the arch shape of front side member, shotgun, and A-pillar were connected well, then the body deformation energy could lift the lower part of A-pillar, effectively reducing vehicle drop. This structure design concept is named “Body Lift Structure” (BLS). The BLS was applied to B and C segment platforms. Additionally, a “Ring” shape was defined by the front side member, dash panel, and A-pillar.
2017-03-28
Technical Paper
2017-01-1437
William Bortles, Sean McDonough, Connor Smith, Michael Stogsdill
Abstract The data obtained from event data recorders found in airbag control modules, powertrain control modules and rollover sensors in passenger vehicles has been validated and used to reconstruct crashes for years. Recently, a third-party system has been introduced that allows crash investigators and reconstructionists to access, preserve and analyze data from infotainment and telematics systems found in passenger vehicles. The infotainment and telematics systems in select vehicles retain information and event data from cellular telephones and other devices connected to the vehicle, vehicle events and navigation data in the form of tracklogs. These tracklogs provide a time history of a vehicle’s geolocation that may be useful in investigating an incident involving an automobile or reconstructing a crash. This paper presents an introduction to the type of data that may be retained and the methods for performing data acquisitions.
2017-03-28
Technical Paper
2017-01-1438
Felix Lee, Peter Xing, Mike Yang, Janice Lee, Craig Wilkinson, Gunter P. Siegmund
Abstract The repeatability and accuracy of front and rear speed changes reported by Toyota’s Airbag Control Modules (ACMs) have been previously characterized for low-severity collisions simulated on a linear sled. The goals of the present study are (i) to determine the accuracy and repeatability of Toyota ACMs in mid-severity crashes, and (ii) to validate the assumption that ACMs function similarly for idealized sled pulses and full-scale vehicle-to-barrier and vehicle-to-vehicle crashes. We exposed three Toyota Corollas to a series of full-scale aligned frontal and rear-end crash tests with speed changes (ΔV) of 4 to 12 km/h. We then characterized the response of another 16 isolated Toyota ACMs from three vehicle models (Corolla, Prius and Camry) and 3 generations (Gen 1, 2 and 3) using idealized sled pulses and replicated vehicle-to-vehicle and vehicle-to-barrier pulses in both frontal and rear-end crashes (ΔV = 9 to 17 km/h).
2017-03-28
Technical Paper
2017-01-1446
Allen Charles Bosio, Paul Marable, Marcus Ward, Bradley Staines
Abstract A dual-chambered passenger airbag was developed for the 2011 USNCAP to minimize neck loading for the belted 5th female dummy while restraining the unbelted 50th dummy for FMVSS208. This unique, patented design adaptively controlled venting between chambers based on occupant stature. A patented pressure-responsive vent on the second chamber permitted aspiration into the second chamber before a delayed outflow to the environment. The delayed flow through the pressure-responsive vent from the second chamber acted like a pressure-limiting membrane vent to advantageously reduce the injury assessment values for the HIC and the Nij for the 5th female dummy.
2017-03-28
Journal Article
2017-01-1475
Saeed Barbat, Xiaowei Li
Abstract On December 2015, The National Highway Traffic Safety Administration (NHTSA) published its proposal to implement U.S New Car Assessment Program (NCAP) changes covering three categories of crashworthiness, crash avoidance and pedestrian protection, beginning with the 2019 model year. The crashworthiness category included a new frontal oblique impact (OI) test protocol. The test compromises of a new Oblique Moving Deformable Barrier (OMDB), new THOR 50th percentile male (THOR-50M) anthropomorphic test device (ATD), and a new test configuration. An OMDB of 2,486 kg (5,480 lb) impacts a stationary target vehicle at a speed of 90 kph (56 mph) at an angle of 15 degrees with a 35% barrier overlap with the front end of the target vehicle. In vehicle-to-vehicle collisions, the lighter weight vehicle experience higher velocity change and higher acceleration levels, thereby, occupants in the lighter vehicle experience higher injury risk.
2017-03-28
Technical Paper
2017-01-1730
Gridsada Phanomchoeng, Sunhapos Chantranuwathana
Abstract Nowadays, the tendency of people using bicycles as the way of transportation has increased as well as the tendency of the bicycle accidents. According to the research of National Highway Traffic Safety Administration (NHTSA), National Survey on Bicyclist and Pedestrian Attitude and Behavior, the major root causes of bicycle accidents are from the road surface condition. Thus, this work has developed the system to detect the road surface condition. The system utilizes the laser and camera to measure the height of road. Then, with the information of the road height and bicycle speed, the road surface condition can be classified into 3 categories due to severe condition of the road. For the secure road, cyclists could safely ride on it. For the warning road, cyclists need to slow down the speed. Lastly, for the dangerous road, cyclists have to stop their bicycles.
2017-03-28
Technical Paper
2017-01-1728
Nitin Singh, Aayoush Sharma, Sameer Shah, Balakumar Gardampaali
Abstract In any unlikely event of accidents or vehicle breakdown, there is accumulation of traffic which results in road-blockage and causes in convenience to other vehicles. If this happens in remote areas, the accidents victims are left unattended and there is delay in providing emergency services. In case of traffic, it obstructs the entry of ambulance and rescue team which results in death of passengers. To prevent this mishap, a mechatronics based road block avoidance and accident alarming system is designed which is automated by the use of sensors. The road-block is detected with the help sensors located at regular intervals on road. This input is given to a Local Control Unit (LCU) which is integrated on every road. Several such LCUs are connected to a Main Control Unit (MCU) which is located at the nearest police station. A single MCU covers the area administered by that police station. Additional CCTV cameras are present to give graphical view of accident.
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
Technical Paper
2017-01-1410
Richard F Lambourn, James Manning
Abstract It can happen, following a collision between a car and a pedestrian or in a deliberate assault with a motor vehicle, that the pedestrian comes to be caught or wedged beneath the car, and that the driver then travels on for a considerable distance, afterwards claiming to have been unaware of the presence of the person. However, police, lawyers and jurors are often incredulous that the driver should not have been able to “feel” that there was something underneath his car. The authors have investigated the matter by carrying out practical tests with suitable cars and dummies. This paper describes instrumented tests performed by the authors following one such incident, and gives accounts of two previous incidents investigated in a more subjective fashion. The general conclusion is that the effect on the behavior of the car is very small and that a driver might indeed be unaware that there was a person trapped beneath them.
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
2017-01-1433
Enrique Bonugli, Joseph Cormier, Matthew Reilly, Lars Reinhart
The purpose of this study was to determine the frictional properties between the exterior surface of a motorcycle helmet and ‘typical’ roadway surfaces. Motorcycle helmet impacts into asphalt and concrete surfaces were compared to abrasive papers currently recommended by government helmet safety standards and widely used by researchers in the field of oblique motorcycle helmet impact testing. A guided freefall test fixture was utilized to obtain nominal impact velocities of 5, 7 and 9 m/s. The impacting surfaces were mounted to an angled anvil to simulate an off-centered oblique collision. Helmeted Hybrid III ATD head accelerations and impact forces were measured for each test. The study was limited to a single helmet model and impact angle (30 degrees). Analysis of the normal and tangential forces imparted to the contact surface indicated that the frictional properties of abrasive papers differ from asphalt and concrete in magnitude, duration and onset.
2017-03-28
Technical Paper
2017-01-1430
Tony R. Laituri, Scott G. Henry
Abstract The present study had three objectives: (1) define a reasonable number of categories to bin head injuries, (2) develop an overarching risk function to estimate head-injury probability based on injury probabilities pertaining to those subordinate categories, and (3) assess the fidelity of both the overarching function and approximations to it. To achieve these objectives, we used real-world data from the National Automotive Sampling System (NASS), pertaining to adult drivers in full-engagement frontal crashes. To provide practical value, we factored the proposed US New Car Assessment Program (US NCAP) and the corresponding Request for Comments from the government. Finally, the NASS data stratifications included three levels of injury (AIS1+, AIS2+, AIS3+), two levels of restraint (properly-belted, unbelted), and two eras based on driver-airbag fitment (Older Vehicles, Newer Vehicles).
2017-03-28
Technical Paper
2017-01-1431
Ke Dong, Brian Putala, Kristen Ansel
Abstract Driver out-of-position (OOP) tests were developed to evaluate the risk of inflation induced injury when the occupant is close to the airbag module during deployment. The Hybrid III 5th percentile female Anthropomorphic Test Device (ATD) measures both sternum displacement and chest acceleration through a potentiometer and accelerometers, which can be used to calculate sternum compression rate. This paper documents a study evaluating the chest accelerometers to assess punch-out loading of the chest during this test configuration. The study included ATD mechanical loading and instrumentation review. Finite element analysis was conducted using a Hybrid III - 5th percentile female ATD correlated to testing. The correlated restraint model was utilized with a Hybrid III - 50th percentile male ATD. A 50th percentile male Global Human Body Model (HBM) was then applied for enhanced anatomical review.
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
2017-01-1406
Changliu Liu, Jianyu Chen, Trong-Duy Nguyen, Masayoshi Tomizuka
Abstract Road safety is one of the major concerns for automated vehicles. In order for these vehicles to interact safely and efficiently with the other road participants, the behavior of the automated vehicles should be carefully designed. Liu and Tomizuka proposed the Robustly-safe Automated Driving system (ROAD) which prevents or minimizes occurrences of collisions of the automated vehicle with other road participants while maintaining efficiency. In this paper, a set of design principles are elaborated as an extension of the previous work, including robust perception and cognition algorithms for environment monitoring and high level decision making and low level control algorithms for safe maneuvering of the automated vehicle.
2017-03-28
Technical Paper
2017-01-1474
Raed E. El-Jawahri, Agnes Kim, Dean Jaradi, Rich Ruthinowski, Kevin Siasoco, Cortney Stancato, Para Weerappuli
Abstract Sled tests simulating full-frontal rigid barrier impact were conducted using the Hybrid III 5th female and the 50th male anthropomorphic test devices (ATDs). The ATDs were positioned in the outboard rear seat of a generic small car environment. Two belt configurations were used: 1) a standard belt with no load limiter or pre-tensioner and 2) a seatbelt with a 4.5 kN load-limiting retractor with a stop function and a retractor pre-tensioner (LL-PT). In the current study, the LL-PT belt system reduced the peak responses of both ATDs. Probabilities of serious-to-fatal injuries (AIS3+), based on the ATDs peak responses, were calculated using the risk curves in NHTSA’s December 2015 Request for Comments (RFC) proposing changes to the United States New Car Assessment Program (US-NCAP). Those probabilities were compared to the injury rates (IRs) observed in the field on point estimate basis.
2017-03-28
Technical Paper
2017-01-0361
Amar Marpu, George Garfinkel, Patrick Maguire
Modeling of high voltage (HV) wires is an important aspect of vehicle safety simulations of electrified powertrains, in order to understand the potential tearing of the wire sheath or pinching of high voltage wiring. The behavior of these wires needs to be reviewed in safety simulations to identify potential hazards associated with a high voltage wire being exposed, severed or coming in contact with ground planes during a crash event. Modeling high voltage wire is challenging due to the complexity of the physical composition of the wire, which is usually comprised of multiple strands bundled and often twisted together to form the high voltage electrical conductor. This is further complicated by the existence of external insulating sheathing materials to prevent high voltage exposure during normal operating conditions. This paper describes a proposed method to model and characterize different types of high voltage wires for usage in component and vehicle level safety models.
2017-03-28
Technical Paper
2017-01-0363
Karthik Ramaswamy, Vinay L. Virupaksha, Jeanne Polan, Biswajit Tripathy
EPP foams are most commonly used in automotive applications for pedestrian protection and to meet low speed bumper regulatory requirements. In today’s automotive world the design of vehicles are predominantly driven by CAE. This makes it necessary to have validated material model for EPP foams in order to simulate and predict performance under various loading conditions. Since most of the automotive OEMs depend on local material suppliers for their global vehicle applications it is necessary to understand the variation in mechanical properties of the EPP foams and their effect on performance predictions. In this paper, EPP foams from three suppliers across global regions are characterized to study the inter-supplier variation in mechanical properties. In order to understand the effect of inter-supplier variation on vehicle performance, LSDYNA rate dependent material model is developed and validated for low speed and pedestrian protection load cases.
2017-03-28
Technical Paper
2017-01-0377
Peter Shery, William Altenhof, Ryan Smith, Elmar Beeh, Philipp Strassburger, Thomas Gruenheid
Cylindrical extrusions of magnesium AZ31B were subjected to quasi-static axial cutting and compression modes of deformation to study this alloy’s effectiveness as an energy absorber. For comparison, the tests were repeated using extrusions of AA6061-T6 aluminum of the same geometry. Axial cutting of AA6061-T6 extrusions has been shown to be an effective, ductile mode of energy dissipation, yielding a repeatable, nearly constant load/deflection response with a crush force efficiency (CFE) up to 96%. In the present tests, the quasi-static cutting deformation of AZ31B extrusions achieved a respectable CFE of 80%, but revealed a load/deflection response with sharp, minute, rapid fluctuations, indicating an undesirable fracturing failure. Additionally, the average specific energy absorption (SEA) of AZ31B was 11 kJ/kg, which is less than half that seen for AA6061-T6 extrusions of the same geometry (24 kJ/kg).
2017-03-28
Technical Paper
2017-01-0373
Fabian Jorg Uwe Koark, Christian Beul
Motivation – Achieving functional safety in mechatronic systems with growing product functionality is a major challenge in systems engineering. Following the current discussion, this challenge is mostly allocated to electronics and software development. For most of the scenarios this focus is feasible. Product design – the construction of the product – defines the properties and the appearance of the product by shape, material and assembly. So, the product design is often not under control of the safety management system. A hazardous deviation of part shape can be easily identified after the parts product or at least at its mounting. A wrong assembly is controlled by assembly documentation or data (e.g. screw torques) and identified at end of assembly line checks. The identification of a hazardous material choice depend on the product material class. Product materials can be separated into two classes: passive or active materials.
2017-03-28
Technical Paper
2017-01-0476
Seiji Furusako, Masatoshi Tokunaga, Masanori Yasuyama
In order to reduce the weight of automobile body, application of high strength steel sheets is expanding. And also a middle and high carbon steel is expected to be used to lower the environmental impact and cost in the field of automobile steel sheet. However, it is necesarry for its realization to enhance the joint strengh of the steel sheets. In this study, hat-shape components were made by resistance spot welding or arc-spot welding using S45C steel sheet of 1.4mm in thick with strength of 1200MPa grade . Then dynamice three-point bending test was carried out on the components and crashworthiness of them was compared. Absorbed energy of the arc-spot welded component was higher than that of the resistance spot-welded one by 30%. Some spot welds fractured (separated) during the three-point bending test but arc-spot welds did NOT fractured. Arc-spot welding is therefore seemed to be effective to improve strength and toughness of weld for a middle and high carbon steel sheet.
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