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Technical Paper

Comparison of Water Strategy Tools for Automotive Manufacturing

Tools are now publicly available that can potentially help a company assess the impact of its water use and risks in relation to their global operations and supply chains. In this paper we describe a comparative analysis of two publicly available tools, specifically the WWF/DEG Water Risk Filter and the WBCSD Global Water Tool that are used to measure the water impact and risk indicators for industrial facilities. By analyzing the risk assessments calculated by these tools for different scenarios that include varying facilities from different industries, one can better gauge the similarities and differences between these water strategy tools. Several scenarios were evaluated using the water tools, and the results are compared and contrasted. As will be shown, the results can vary significantly.
Journal Article

Modeling of an Advanced Steering Wheel and Column Assembly for Frontal and Side Impact Simulations

This paper presents the final phase of a study to develop the modeling methodology for an advanced steering assembly with a safety-enhanced steering wheel and an adaptive energy absorbing steering column. For passenger cars built before the 1960s, the steering column was designed to control vehicle direction with a simple rigid rod. In severe frontal crashes, this type of design would often be displaced rearward toward the driver due to front-end crush of the vehicle. Consequently, collapsible, detachable, and other energy absorbing steering columns emerged to address this type of kinematics. These safety-enhanced steering columns allow frontal impact energy to be absorbed by collapsing or breaking the steering columns, thus reducing the potential for rearward column movement in severe crashes. Recently, more advanced steering column designs have been developed that can adapt to different crash conditions including crash severity, occupant mass/size, seat position, and seatbelt usage.
Journal Article

Modeling of Adaptive Energy Absorbing Steering Columns for Dynamic Impact Simulations

The objective of this paper focused on the modeling of an adaptive energy absorbing steering column which is the first phase of a study to develop a modeling methodology for an advanced steering wheel and column assembly. Early steering column designs often consisted of a simple long steel rod connecting the steering wheel to the steering gear box. In frontal collisions, a single-piece design steering column would often be displaced toward the driver as a result of front-end crush. Over time, engineers recognized the need to reduce the chance that a steering column would be displaced toward the driver in a frontal crash. As a result, collapsible, detachable, and other energy absorbing steering columns emerged as safer steering column designs. The safety-enhanced construction of the steering columns, whether collapsible, detachable, or other types, absorb rather than transfer frontal impact energy.
Journal Article

Idealized Vehicle Crash Test Pulses for Advanced Batteries

This paper reports a study undertaken by the Crash Safety Working Group (CSWG) of the United States Council for Automotive Research (USCAR) to determine generic acceleration pulses for testing and evaluating advanced batteries subjected to inertial loading for application in electric passenger vehicles. These pulses were based on characterizing vehicle acceleration time histories from standard laboratory vehicle crash tests. Crash tested passenger vehicles in the United States vehicle fleet of the model years 2005-2009 were used in this study. Crash test data, in terms of acceleration time histories, were collected from various crash modes conducted by the National Highway Traffic Safety Administration (NHTSA) during their New Car Assessment Program (NCAP) and Federal Motor Vehicle Safety Standards (FMVSS) evaluations, and the Insurance Institute for Highway Safety (IIHS).
Technical Paper

Crash Test Pulses for Advanced Batteries

This paper reports a 2010 study undertaken to determine generic acceleration pulses for testing and evaluating advanced batteries for application in electric passenger vehicles. These were based on characterizing vehicle acceleration time histories from standard laboratory vehicle crash tests. Crash tested passenger vehicles in the United States vehicle fleet of the model years 2005-2009 were used. The crash test data were gathered from the following test modes and sources: 1 Frontal rigid flat barrier test at 35 mph (NHTSA NCAP) 2 Frontal 40% offset deformable barrier test at 40 mph (IIHS) 3 Side moving deformable barrier test at 38 mph (NHTSA side NCAP) 4 Side oblique pole test at 20 mph (US FMVSS 214/NHTSA side NCAP) 5 Rear 70% offset moving deformable barrier impact at 50 mph (US FMVSS 301). The accelerometers used were from locations in the vehicle where deformation is minor or non-existent, so that the acceleration represents the “rigid-body” motion of the vehicle.
Technical Paper

Biomechanical Assessment of a Rear-Seat Inflatable Seatbelt in Frontal Impacts

This study evaluated the biomechanical performance of a rear-seat inflatable seatbelt system and compared it to that of a 3-point seatbelt system, which has a long history of good real-world performance. Frontal-impact sled tests were conducted with Hybrid III anthropomorphic test devices (ATDs) and with post mortem human subjects (PMHS) using both restraint systems and a generic rear-seat configuration. Results from these tests demonstrated: a) reduction in forward head excursion with the inflatable seatbelt system when compared to that of a 3-point seatbelt and; b) a reduction in ATD and PMHS peak chest deflections and the number of PMHS rib fractures with the inflatable seatbelt system and c) a reduction in PMHS cervical-spine injuries, due to the interaction of the chin with the inflated shoulder belt. These results suggest that an inflatable seatbelt system will offer additional benefits to some occupants in the rear seats.
Journal Article

Crash Performance Simulation of a Multilayer Thermoplastic Fuel Tank with Manufacturing and Assembly Consideration

The modeling of plastic fuel tank systems for crash safety applications has been very challenging. The major challenges include the prediction of fuel sloshing in high speed impact conditions, the modeling of multilayer thermoplastic fuel tanks with post-forming (non-uniform) material properties, and the modeling of tank straps with pre-tensions. Extensive studies can be found in the literature to improve the prediction of fuel sloshing. However, little research had been conducted to model the post-forming fuel tank and to address the tension between the fuel tank and the tank straps for crash safety simulations. Hoping to help improve the modeling of fuel systems, the authors made the first attempt to tackle these major challenges all at once in this study by dividing the modeling of the fuel tank into eight stages. An ALE (Arbitrary Lagrangian-Eulerian) method was adopted to simulate the interaction between the fuel and the tank.
Technical Paper

Seatback Strength and Occupant Response in Rear Impact Crash: Observations with Respect to Large Occupant Size and Position

Seatback strength and injury potential in moderate to high-speed rear-end collisions were investigated in a series of 12 HYGE sled tests. The test methodology included the use of instrumented Hybrid-III anthropomorphic test devices (ATDs). Four tests employed a 95th percentile male ATD ballasted to a total weight of 300 lbs and subjected to approximate 15 mph Delta-V impacts. The remaining tests employed an unmodified 50th percentile male ATD with impacts of approximately 25 mph Delta-V, and three ATD positions, including two "out of position" postures corresponding to leaning forward ("forward" position), and leaning forward and inboard ("radio" position). Seats from three different vehicles were tested, representing a range of strength values. Upper neck values for N were less than 1.0 in all cases. Lower neck N values sometimes exceeded 1.0 with the 50th percentile male ATD out of position, and these values did not trend with seatback strength.
Technical Paper

In-Vehicle Ambient Condition Sensing Based on Wireless Internet Access

Increasing electronics content, growing computing power, and proliferation of opportunities for information connectivity (through improved sensors, GPS, road and traffic information systems, wireless internet access, vehicle-to-vehicle communication, etc.) are technology trends which can significantly transform and impact future automotive vehicle's control and diagnostic strategies. One aspect of the increasing vehicle connectivity is access to ambient and road condition information, such as ambient temperature, ambient pressure, humidity, % cloudiness, visibility, cloud ceiling, precipitation, rain droplet size, wind speed, and wind direction based on wireless internet access. The paper discusses the potential opportunities made available through wireless communication between the vehicle and the internet.
Journal Article

Axial Crash Testing and Finite Element Modeling of A 12-Sided Steel Component

To improve the energy absorption capacity of front-end structures during a vehicle crash, a novel 12-sided cross-section was developed and tested. Computer-aided engineering (CAE) studies showed superior axial crash performance of the 12-sided component over more conventional cross-sections. When produced from advanced high strength steels (AHSS), the 12-sided cross-section offers opportunities for significant mass-savings for crash energy absorbing components such as front or rear rails and crush tips. In this study, physical crash tests and CAE modeling were conducted on tapered 12-sided samples fabricated from AHSS. The effects of crash trigger holes, different steel grades and bake hardening on crash behavior were examined. Crash sensitivity was also studied by using two different part fabrication methods and two crash test methods. The 12-sided components showed regular folding mode and excellent energy absorption capacity in axial crash tests.
Technical Paper

Passive Safety Technologies and Belted ATD Neck Loads in Rollover Events

Two rigid rollover test devices were constructed to have the approximate dimensions, mass and inertial properties of a mid-sized Car and Sport Utility Vehicle (SUV). The rigid devices were used to generate vehicle and occupant responses from a series of laboratory rollover tests. For each rigid rollover test, a deceleration sled was used to subject each rigid vehicle to nearly identical lateral speeds and decelerations. The rigid vehicles were limited to a single roll by tethering the vehicles to the deceleration cart. The vehicle's roll rate, roll angle, lateral acceleration and Anthropomorphic Test Devices (ATD) neck responses generated from the rigid SUV were compared to the responses of a full vehicle production SUV under similar test conditions. The rigid SUV and Car devices were then used to examine the effects of activating safety belt pre-tensioning systems and roof mounted side curtain airbags at various times on ATD neck forces and moments.
Technical Paper

Thoracic Response of Belted PMHS, the Hybrid III, and the THOR-NT Mid-Sized Male Surrogates in Low-Speed, Frontal Crashes

Injury to the thorax is the predominant cause of fatalities in crash-involved automobile occupants over the age of 65, and many elderly-occupant automobile fatalities occur in crashes below compliance or consumer information test speeds. As the average age of the automotive population increases, thoracic injury prevention in lower severity crashes will play an increasingly important role in automobile safety. This study presents the results of a series of sled tests to investigate the thoracic deformation, kinematic, and injury responses of belted post-mortem human surrogates (PMHS, average age 44 years) and frontal anthropomorphic test devices (ATDs) in low-speed frontal crashes. Nine 29 km/h (three PMHS, three Hybrid III 50th% male ATD, three THOR-NT ATD) and three 38 km/h (one PMHS, two Hybrid III) frontal sled tests were performed to simulate an occupant seated in the right front passenger seat of a mid-sized sedan restrained with a standard (not force-limited) 3-point seatbelt.
Technical Paper

Fatigue Analysis for Axle Differential Cases

The recent trends of increasing driveline torque and use of traction control devices call for increasingly higher durability capacity from driveline components. Bench and vehicle durability tests are often used to validate designs, but they are not cost-effective and take months to complete. Traditional finite element analysis (FEA) procedures have been used effectively in the re-design of driveline components to reduce stress, and occasionally, to predict fatigue life. But in the case of certain rotating components, such as the Axle Differential Case, where the component sees large stress/strain fluctuations within the course of one complete rotation, even under constant input torque, historical fatigue analysis (when conducted) yields very conservative results. The axle differential case tends to be one of the weakest links in the rear axle assembly. Therefore, there is a crucial need for analytical methods to more accurately predict fatigue life to reduce testing time and cost.
Technical Paper

Development and Evaluation of a Proposed Neck Shield for the 5th Percentile Hybrid III Female Dummy

Frontal airbag interaction with the head and neck of the Hybrid III family of dummies may involve a nonbiofidelic interaction. Researchers have found that the deploying airbag may become entrapped in the hollow cavity behind the dummy chin. This study evaluated a prototype neck shield design, the Flap Neck Shield, for biofidelic response and the ability to prevent airbag entrapment in the chin/jaw cavity. Neck pendulum calibration tests were conducted for biofidelity evaluation. Static and dynamic airbag deployments were conducted to evaluate neck shield performance. Tests showed that the Flap Neck Shield behaved in a biofidelic manner with neck loads and head motion within established biofidelic limits. The Flap Neck Shield did not alter the neck loads during static or dynamic airbag interactions, but it did consistently prevent the airbag from penetrating the chin/jaw cavity.
Technical Paper

Finite element simulation of drive shaft in truck/SUV frontal crash

Drive shaft modelling effects frontal crash finite element simulation. A 35 mph rigid barrier impact of a body on frame SUV with an one piece drive shaft and a unibody SUV with a two piece drive shaft have been studied and simulated using finite element analyses. In the model, the drive shaft can take significant load in frontal impact crash. Assumptions regarding the drive shaft model can change the predicted engine motion in the simulation. This change influences the rocker @ B-pillar deceleration. Two modelling methods have been investigated in this study considering both joint mechanisms and material failure in dynamic impact. Model parameters for joint behavior and failure should be determined from vehicle design information and component testing. A body on frame SUV FEA model has been used to validate the drive shaft modeling technique by comparing the simulation results with crash test data.
Technical Paper

An Assessment of Vehicle Side-Window Defrosting and Demisting Process

The thermal comfort of passengers within a vehicle is often the main objective for the climate control engineer; however, the need to maintain adequate visibility through the front and side windows of a vehicle is a critical aspect of safe driving. This paper compares the performance of the side window defrosting and demisting mechanism of several current model vehicles. The study highlights the drawbacks of current designs and points the way to improved passive defrosting mechanisms. The investigation is experimental and computational. The experiments are carried out using full-scale current vehicle models. The computational study, which is validated by the experiments, is used to perform parametric investigation into the side window defrosters performance. The results show that the current designs of the side-defroster nozzles give maximum airflow rates in the vicinity of the lower part of the window, which yields unsatisfactory visibility.
Technical Paper

Digital Occupant: Personal Immersion for Subjective Evaluations of a Vehicle

Ford’s use of digital mockups in vehicle design has improved the package and fit of components and systems within the vehicle. However, to fully meet and exceed the consumer’s expectations of a vehicle it is crucial to make subjective evaluations of a vehicle’s comfort, convenience, visibility, and accessibility early in the design process. Efficient and nimble design requires an understanding of the subjective qualities of the vehicle before any physical prototypes exist. The Digital Occupant personally immerses an individual (e.g. member of the design team, market researcher or consumer) within the digital mockup earlier to facilitate these subjective evaluations. This paper describes the technologies and emerging methodologies integrated to produce the Digital Occupant. This personally immersive simulation includes a full body real-time dynamic digital representation of the individual being immersed.
Technical Paper

Assessment of Magnetohydrodynamic Angular Rate Sensors in Measuring Ankle Rotations During Vehicle's Crash Tests

While testing vehicles for crash, particularly the offset frontal crash mode, new devices and techniques are needed to enhance the ability to measure rotations of certain vehicle components and dummy parts (or joints). The reason for this new demand is that the capabilities of existing techniques or devices in measuring rotations of small masses in confined areas are limited. Examples of the desired measurements are the rotations of dummy's feet and tibias as well as the rotations of the vehicle's toe-board during intrusion. These measurements help to understand dummy's ankle loads as a result of different intrusion rates. Furthermore, having these measurements is very beneficial to the validation of the computer models used in simulating the behavior of dummy's lower extremities in high intrusion crashes. Recent research demonstrated the use of an angular rate sensor, based on magnetohydrodynamic principles, on Hybrid-III dummies and cadavers.
Technical Paper

Prediction of Front TTI in NHTSA Side Impact Using a Regression-Based Approach

Vehicle side impact performance is potentially affected by a large number of parameters which may be related to body stiffness and energy absorption characteristics, and packaging dimensions. An understanding of the principal variables controlling TTI (Thoracic Trauma Index) is fundamental to the achievement of high LINCAP (Lateral Impact New Car Assessment Program) rating especially for sedans. In the present study, the effects on TTI of the following are considered: response-related parameters such as velocity and intrusion (which are in turn related to body structure), countermeasures such as side airbag, and dummy to structure clearance dimensions. With the help of test data gathered from side impact tests carried out on cars and trucks at Ford, a new “best subset” regression model is developed and is shown to be able to predict TTI for a number of LINCAP tests which were not part of the suite used in the derivation of the model.
Technical Paper

The Strain Gauge Goniometer, a New Sensor to Measure Dummy Joint Angles Under Crash Conditions

The paper describes the use of strain gauge goniometers to measure dummy leg joint angles in impact tests. The instruments have been developed based on regular goniometers used for human gait analysis. Specific modifications enhanced the mechanical stability and the electrical insulation of the sensors. They are now compatible with standard crash data acquisition systems. Several vehicle crash tests have been analyzed using the goniometers as a supplementary measurement device. Due to its low weight, the device does not significantly alter the dummy behavior. Further areas of application are outlined in the paper.