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Vehicle-to-Vehicle (V2V) safety application research based on short range real-time communication has been researched for over a decade. Examples of V2V applications include Electronic Emergency Brake Light, Do Not Pass Warning, Lane Departure Warning, and Intersection Movement Assist. It is hoped that these applications, whether present as warning or intervention, will help reduce the incidence of traffic collisions, fatalities, injuries, and property damage. The safety benefits of these applications will likely depend on many factors, such as usability, market penetration, driver acceptance, and reliability. Some applications, such as DNPW and IMA, require a longer communication range to be effective. In addition, Dedicated Short Range Communications (DSRC) may be required to communicate without direct line of sight. The signal needs to overcome shadowing effects of other vehicles and buildings that are in the way.

Implementing the Voice of the customer is one of the main challenges during the Vehicle Development Process. The variety of desired vehicle attributes requires well-defined processes that include manufacturability along with the voice of the customer in all aspects of the product development process. Customer's defined attributes along with regulations and manufacturability requirements should flow through all process phases starting from the early concept development phase. This paper discusses a lean design approach to assure that the voice of the customer attributes are addressed and balanced through the product development process from concept to production. The lean approach includes architectural, performance, and manufacturability as key development attributes. A case study of Automotive Modular Door System is presented to demonstrate the application of the lean approach in the design and development of complex automotive systems.

The in-cylinder extent of liquid-phase fuel penetration (i.e., the liquid length) is an important parameter in combustion-chamber design because liquid lengths that are too long can lead to wall impingement and corresponding degradation of engine efficiency, emissions, and durability. Previous liquid-length measurements in constant-volume combustion chambers have shown that the liquid length is nominally independent of injection pressure, but these measurements have employed common-rail fuel systems where injection rate is approximately constant during the entire injection event, and they have been conducted under quasi-steady ambient thermodynamic conditions. The objective of the current work is to better understand the effects of injection-rate shape and injection pressure on the liquid length, including possible effects of unsteady ambient conditions in an engine.

Failure modes of friction stir spot welds in lap-shear specimens of dissimilar high strength dual phase steel (DP780GA) and hot stamped boron steel (HSBS) sheets are investigated under quasi-static and cyclic loading conditions based on experimental observations. Optical micrographs of dissimilar DP780GA/HSBS friction stir spot welds made by a concave tool before and after failure are examined. The micrographs indicate that the failure modes of the welds under quasi-static and cyclic loading conditions are quite similar. The micrographs show that the DP780GA/HSBS welds mainly fail from cracks growing through the upper DP780GA sheets where the concave tool was plunged into during the welding process. Based on the observed failure modes, a kinked fatigue crack growth model is adopted to estimate fatigue lives.

The thin-shell structured beams that are used extensively in the vehicle body need to satisfy both strength requirements for crash safety and demands for weight reductions for environmental friendliness. This study focused on the loading rate dependence of reaction force, especially the maximum value, which is generated in thin-shell structured beams as a result of axial force inputs in a frontal crash. The mechanism generating the reaction force was made clear through a comparison with classical Euler buckling(1) and von Karman's effective width expression(2). It was observed that a square cross section displays markedly large loading rate dependence, which can be approximated well by considering the effect of inertial force in the high loading rate region and by von Karman's effective width solution in the low loading rate region. Essentially, this dependence is governed by Euler buckling.

Filled-rubber is widely used in automotive applications for noise and vibration isolation. The inherent material characteristics of filled-rubber make it suitable for these applications, but its complicated nonlinear behavior under both static and dynamic loading can make material modeling a challenge. This paper presents a two-element overlay technique to capture the nonlinear vibration amplitude dependency of a carbon-filled rubber material commonly referred to as the “Payne Effect.” This overlay technique is practically applied to predict the nonlinear dynamic stiffness and damping loss characteristics of a carbon-filled rubber body cab mount component from a body-on-frame vehicle calculated as a function of large static pre-strain, dynamic excitation frequency, and small dynamic strain amplitude in a single analysis.

To optimize the tyre contact patch in a sports car, Ferrari has developed an active camber and toe (ACT) system comprising of 4 actuators for the rear axle. This complex and completely new system is difficult to model accurately and for this reason, it was decided to combine a physical prototype with a full vehicle model to carry out the functional tests. The method of combining a virtual model with a physical test is known as hybrid simulation. This functional testing of both the actuators and the vehicle dynamics logic will be performed on an MTS 6DOF bench test prior to physical track testing on a prototype vehicle using Ferrari facility in Maranello, Italy. In support of this functional testing, we will use hybrid simulation techniques with software and methods specifically developed. The planned hybrid test system described in the paper will allow dynamic coupling between the physical bench test and a modified full vehicle simulation model.

This paper describes the correlation of a person's age to the risk of injury occurrence and the corresponding injury severity in traffic accidents. A representative sample of belted drivers was analyzed by using data from the German In-Depth-Accident Study (GIDAS) to investigate the influence of age on injury severity and special injuries to different body regions. The study focused on two age groups: 17-30 year old (younger drivers) and older drivers 50 year old and older (50+). The injury risk was described as a function of delta-v and injury risk curves based on Abbreviated Injury Scale (AIS). Furthermore, individual parameters like age and body mass index (BMI) as well as age and mass of the vehicle were considered. The statistical analysis was carried out using descriptive and multivariate statistics. This paper presents an overview of injury patterns of belted drivers and the probability of these drivers being injured in different accident scenarios.

A three-step process was developed to estimate fracture criteria for a human body model. The process was illustrated via example wherein skull fracture criteria were estimated for the Ford Human Body Model (FHBM)~a finite element model of a mid-sized human male. The studied loading condition was anterior-to-posterior, blunt (circular/planar) cylinder impact to the frontal bone. In Step 1, a conditional reference risk curve was derived via statistical analysis of the tests involving fractures in a recently reported dataset (Cormier et al., 2011a). Therein, Cormier et al., authors reported results for anterior-to-posterior dynamic loading of the frontal bone of rigidly supported heads of male post mortem human subjects, and fracture forces were measured in 22 cases. In Step 2, the FHBM head was used to conduct some underlying model validations relative to the Cormier tests. The model-based Force-at-Peak Stress was found to approximate the test-based Fracture Force.

Head injuries are the most common injuries sustained by children in motor vehicle crashes regardless of age, restraint and crash direction. Previous research identified the front seat back as relevant contact point associated with head injuries sustained by restrained rear seated child occupants. The objective of this study was to conduct a test series of headform impacts to seat backs to evaluate the energy management characteristics of relevant contact points for pediatric head injury. A total of eight seats were tested: two each of 2007 Ford Focus, Toyota Corolla, 2006 Volvo S40, and 2008 Volkswagen Golf. Five to six contact points were chosen for each unique seat model guided by contact locations determined from real world crashes. Each vehicle seat was rigidly mounted in the center track position with the seatback angle adjusted to 70 degrees above the horizontal.

Design optimization techniques are widely used to drive designs toward a global or a near global optimal solution. However, the achieved optimal solution often appears to be the only choice that an engineer/designer can select as the final design. This is caused by either problem topology or by the nature of optimization algorithms to converge quickly in local/global optimal or both. Problem topology can be unimodal or multimodal with many local and/or global optimal solutions. For multimodal problems, most global algorithms tend to exploit the global optimal solution quickly but at the same time leaving the engineer with only one choice of design. The paper explores the application of genetic algorithms (GA), simulated annealing (SA), and mixed integer problem sequential quadratic programming (MIPSQP) to find multiple local and global solutions using single objective optimization formulation.

In September 2009 the National Highway Traffic Safety Administration (NHTSA) published a report that investigated the incidence of fatalities to belted non-ejected occupants in frontal crashes involving late-model vehicles. The report concluded that after exceedingly severe crashes, the largest number of fatalities occurred in crashes involving poor structural engagement between the vehicle and its collision partner, present in crashes characterized as corner impacts, oblique crashes, impacts with narrow objects, and heavy vehicle underrides. By contrast, few if any of these 122 fatal crashes were full-frontal or offset-frontal impacts with good structural engagement, excepting crashes that were of extreme severity or the occupants that were exceptionally vulnerable. The intent of this research program is to develop a test protocol that replicates real-world injury potential in small overlap impacts (SOI) and oblique offset impacts (Oblique) in motor vehicle crashes.

The purpose of the study was to distinguish the role of vehicle structure in frontal impacts in published coded National Automotive Sampling System (NASS-CDS) data. The criteria used: Collision Deformation Classification (CDC) coding rules, crush profile locator data and the projected location of longitudinal structural members in models of vehicle class sizes used by NASS-CDS. Two classifiers were developed to augment the CDC system. The Coincidence classifier indicates the relationship between the quadrant of the clock face the crash vector originates in and the aspect of the end plane the center of damage is located. It has three values: Linear (12 o'clock impacts) Consistent and Variant ("oblique" Principal Directions of Force or PDOFs). The second classifier indicates the number of longitudinal members engaged: 0, 1 or 2. NASS-CDS data for sample years 2005 to 2009 was filtered for occupants involved in impacts with the highest ranked speed change assigned to the front-end plane.

Airflow over the Ahmed body is simulated by means of the Embedded LES technique. This is a zonal approach which allows the LES turbulence model to be used in a sub-domain while the rest of the domain is solved using a RANS turbulence model, i.e., the kω-SST model. This allows the LES zone to be restricted to the rear end of the vehicle where the unsteadiness of the flow must be accurately predicted. A comparison with full RANS modeling and experiments is reported.

A numerical method to simulate aeroacoustic fields around automobiles is proposed in the present paper. The proposed method can be used to compute sound emissions directly in both far fields and near fields. Sound passes through body structures near A-pillars and rear-view mirrors. The direct predictions of the sound to passengers therefore require solutions of acoustic near fields. Most aeroacoustics simulations around automobiles are based on Lighthill's analogy. Strictly speaking, Lighthill's analogy is not consistent in near fields because near fields are not governed by a simple wave equation. In the present paper, a proper approach is proposed to achieve further progress in the simulation of aeroacoustic fields around automobiles. The difficulties occur because the sound pressure is much smaller than the vortical flow pressure.

A wind-tunnel experiment investigating unsteady flow phenomena around a generic notchback during single crosswind gusts is modeled with the open source CFD package OpenFOAM®. The overall objective is to assess the capability and accuracy achieved by the simulation tool with respect to its potential for industrial usage. Transient yaw simulations apply a sliding interface between two computational grids, which are generated using the commercial software Spider®. It is shown that a stable simulation process is feasible but requires long computation times. The physical accuracy of the investigated phenomena depends on the computational grid and on the turbulence model used. Although the obtained aerodynamic loads qualitatively correspond with the experimental results, the absolute values are not satisfactory when working with a coarse grid with 6.2 million cells. Then, characteristic surface pressure distributions and their transient development differ from the experimental data.

The objective of this study was to further validate three previously-developed, age-dependent finite element models representing 35, 55, and 75 year old mid-sized males. The validation was based on comparisons with the following published tests involving post mortem human subjects: oblique thoracic and abdominal pendulum impact (4-10 m/s), oblique and lateral thoracic pendulum impact (2.5 m/s), and lateral thoracic pendulum impact (4.3 and 6.7 m/s). The responses of the models were compared to cadaveric response corridors and responses from specific cadavers similar in size and age. When compared to the cadaveric response corridors, the model responses were generally within those corridors. When compared to the responses of specific cadavers, the results were mixed. In some of the cases the model responses predicted the age-dependency of the cadaveric responses. In other cases, the model responses had the opposite trend of those of the cadavers.

The purpose of this study was to determine if quasi-static (QS) bumper force-deformation (F-D) data could be used in a low-speed bumper-to-bumper simulation model (1) in order to reconstruct low-speed crashes. In the simulation model, the bumpers that make contact in a crash are treated as a system. A bumper system is defined as the two bumpers that interact in a crash positioned in their orientation at the time of the crash. A device was built that quasi-statically crushes the bumpers of a bumper system into each other and measures the compression force and the deformation of the bumper system. Three bumper systems were evaluated. Two QS F-D measurements were performed for each bumper system in order to demonstrate the repeatability of the QS F-D measurement. These measurements had a compression phase and a rebound phase. A series of crash tests were performed using each bumper system.

This paper presents simulations for the prediction of the flow around a passenger vehicle. The flow solver used is ISIS-CFD developed by the Numerical Modeling Group of the Fluid Mechanics Laboratory of Ecole Centrale de Nantes. The CFD simulation is carried out with the Explicit Algebraic Stress Model (EASM) turbulence model. For improved precision, the recently developed automatic adaptive grid refinement procedure of the flow solver is used. This procedure is built for unstructured hexahedral grids and naturally supports both isotropic and anisotropic grid refinement to keep the grid sizes small for 3D simulations. The refinement criterion used to indicate the locations of grid refinement is based on the second spatial derivatives of the pressure. This criterion is efficient for flows with strong local vorticity. Three models are used to validate this approach: the Ahmed model, the Willy model and a pickup truck model.

Water accumulating on a vehicle's wind screen, driven over the A-pillar by a combination of aerodynamic forces and the action of the windscreen wipers, can be a significant impediment to driver vision. Surface water film, or streams, persisting in key vision areas of the side glass can impair the drivers' ability to see clearly through to the door mirror, and laterally onto junctions. Common countermeasures include: water management channels and hydrophobic glass coatings. Water management channels have both design and wind noise implications. Hydrophobic coatings entail significant cost. In order to manage this design optimisation issue a water film and wiper effect model has been developed in collaboration with Jaguar Land Rover, extending the capabilities of the PowerFLOW CFD software. This is complimented by a wind-tunnel based test method for development and validation. The paper presents the progress made to date.