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Vehicle-to-Grid (V2G) technology is expected to play a role in addressing the imbalance between periods of peak demand and peak supply on the electricity grid. V2G technology enables two-way power flow between the grid and the high-power, high-capacity propulsion batteries in an electrified vehicle. That is, V2G allows the vehicle to store electricity during peak supply periods, and then discharge it back into the grid during peak demand periods. The authors have performed an architectural design and a modeling and simulation study for a bi-directional wireless charging system for V2G applications. This research activity aims to adapt an existing SAE J2954 compatible uni-directional system design to enable bi-directional wireless power transfer with minimum impact to system cost, while maintaining full compatibility with the requirements of SAE J2954.

Characterization of the plastic and ductile fracture behavior of a ferrous casting commonly used for the steering knuckle of an automotive suspension system is presented in this work. Ductile fracture testing for various coupon geometries was conducted to simulate a wide range of stress states. Failure data for the higher stress triaxiality were obtained from tension tests conducted on thin flat specimens, wide flat specimens and axisymmetric specimens with varying notch radii. The data for the lower triaxiality were generated from thin-walled tube specimens subjected to torsional loading and compression tests on cylindrical specimens. The failure envelopes for the material were developed utilizing the test data and finite element (FE) simulations of the corresponding test specimens. Experiments provided the load-displacement response and the location of fracture initiation.

The choice of an appropriate material model with parameters derived from testing and proper modeling of stress-strain response during cyclic loading are the critical steps for accurate fatigue-life prediction of complex automotive subsystems. Most materials used in an automotive substructure, like a chassis system, exhibit combined hardening behavior and it is essential to capture this behavior in the CAE model in order to accurately predict the fatigue life. This study illustrates, with examples, the strain-controlled testing of material coupons, and the calculations of material parameters from test data for the combined hardening material model used in the Abaqus solver. Stress-strain response curves and fatigue results from other simpler material models like the isotropic hardening model and the linear material model with Neuber correction are also discussed in light of the respective fatigue theories.

The objectives of a new generation of light trucks required the development of a new platform chassis, using advances in packaging, manufacturing efficiency, mass reduction, fuel efficiency, noise and vibration toughness, and ride comfort, while maintaining the vehicle's fun-to-drive character. This paper outlines the chassis component and packaging integration, light weight material application with structural optimization, as well as technical concepts executed to improve performance. Key component focus points are axles and bearings, wheels, tires, suspensions, brakes, engine cradles and sub-frames, steering systems, mechanical controls, and fuel and exhaust systems.

Currently, car bodies require further weight reduction in order to support increasing fuel economy requirements. An efficient way for light weight body design is to include body member size as a design variable in addition to part thickness. However it is currently difficult for finite element (FE) models to change member size even using current morphing techniques. To break through this challenge, a hybrid modeling approach was developed which combines shell and beam element representations of body structural members. The original member shell element thickness was decreased by 40%. Then the stiffness reduction caused by this change is offset by beam elements incorporated inside these members. These beams can represent the stiffness change due to new cross sectional dimensions or orientations without changing the original shell elements, thus avoiding modeling instabilities that can occur from morphing.

This paper describes the new Honda R&D Americas Scale Model Wind Tunnel (SWT). To help address Honda's ongoing need to improve fuel economy, reduce the driving force of a vehicle, and decrease product development time, the wind tunnel was developed and implemented to achieve high accuracy aerodynamic predictions for product development and a significantly improved capability for vehicle aerodynamics research. The SWT can accommodate model scales up to 50%. The ¾-open jet test section has a top speed of 250 km/h, a 5-belt moving ground plane with a long center belt for proper wake simulation, a test section designed specifically for very low static pressure gradient, three separate dynamic pressure measurement systems for state-of-the-art blockage corrections, and an overhead traverse for specialized measurement activities. This paper describes the decision process that led to the SWT, key commissioning results, and performance validation results with models installed.

Considerable improvements can be obtained in battery performance for hybrid electric vehicles (HEVs) by employing an electrochemistry-transport model based on a multi-physics modeling framework and ultrafast numerical algorithms. One important advantage of this approach over the lumped equivalent circuit (or look-up table) approach is the ability of the former to adapt to changes in design and control. In this work, we present mathematical and numerical details of our approach, and demonstrate the robustness of this battery model in simulation of short-pulse charge/discharge characteristic of HEV driving cycles under room and low temperatures.

The pressure of the combustion gas in a diesel engine is higher than that in a gasoline engine, so the cylinder head gasket that seals the combustion chamber is exposed to a severe environment. The sealability of the gaskets is affected not only by the gasket specifications, but also by the cylinder head, cylinder block, and the head bolts that clamp them. Consequently, in order to improve the performance of these gaskets, it is essential to enhance their material characteristics. Because the necessary characteristics of a gasket material are high strength and high fatigue strength, methods of realizing these enhancements were studied, and a new material was developed. It was confirmed that a gasket made using the newly developed material withstood high combustion pressure, and the gasket was used in a high performance diesel engine.

An objective benchmarking process for vehicle dynamics that incorporates both test and simulation was used in the development of a sedan. Data from objective measurements of vehicle handling response was used as input to simulation. Simulation results generated a range of system level characteristics to evaluate on a test vehicle. In detail, this process includes system level vehicle simulation software for model building and generating an array of output characteristics. The directional changes were then applied to early build prototype vehicles for focused objective and subjective vehicle evaluation.

A simulation tool has been developed for predicting steering effort of a vehicle during steering power-assist system failure. The vehicle system is modeled with the inclusion of a system-level vehicle model and a steering system model that are linked together through the steering moment at the kingpin and front road wheel angle. A driver model has also been designed to provide closed-loop steering angular input to make the car follow a certain target path. The simulation model is correlated well with actual vehicle tests under various steering input and lateral acceleration conditions. Also illustrated are some examples of comparison between measured and simulated sensitivity study for selected factors.

Driveline torque distribution has long been a research topic, and in the last several decades research has been directed towards enhancing on-road vehicle stability and agility through application of controllable driveline systems. This paper discusses the impact of Direct Yaw Control AWD systems (DYC AWD Systems) on the combined acceleration and turning performance as it pertains to maneuverability and stability on all road surfaces. To achieve higher levels of both safety and performance, the application of a controllable DYC AWD system capable of applying direct yaw moment to the vehicle chassis serves as a key goal to achieve the optimal result. A classification of existing driveline systems is discussed and compared to these optimal requirements. Representative on-vehicle scenarios are discussed to illustrate the impact of AWD control on the vehicle stability and maneuverability and to highlight the effects to the vehicle operator.

As we continue to create ever-lighter road vehicles, the challenge of balancing weight reduction and structural performance also continues. One of the key parts this occurs on is the hood, where lighter materials (e.g. aluminum) have been used. However, the aerodynamic loads, such as hood lift, are essentially unchanged and are driven by the front fascia and front grille size and styling shape. This paper outlines a combination CFD/FEA prediction method for hood deflection performance at high speeds, by using the surface pressures as boundary conditions for a FEA linear static deflection analysis. Additionally, custom post-processing methods were developed to enhance flow analysis and understanding. This enabled the modification of existing test methods to further improve accuracy to real world conditions. The application of these analytical methods and their correlation with experimental results are discussed in this paper.

The cost of fuel and the desire for fuel efficiency continue to drive automobile manufacturers to invest in and to prioritize vehicle designs and performance. There has long been a fundamental understanding that aerodynamic efficiency (drag) has an effect on this phenomenon. The focus of this paper is to demonstrate how emergent aerodynamic performance calculation tools can be efficiently and effectively utilized for realizing improvements to vehicle performance, thereby enhancing customer satisfaction and societal acceptance. These tools include Computational Fluid Dynamic analysis (CFD) which further includes visualization techniques, shape deformation, DOE, and optimization methods, among others.

Magnetorheological (MR) dampers have been used in the market on various vehicles since 2001. They use a special oil-based fluid (Magnetorheological Fluid, MRF) that contains small iron particles (1-10 μm in size) and a controllable electromagnetic piston to allow a wide range of damping forces. The system's wide range of available damping force combined with nearly instantaneous response time helps maximize body control while simultaneously providing outstanding ride comfort. This paper describes how the MR technology was combined with conventional suspension tuning to achieve an enhanced level of dynamic performance. While the MR damper offers enhanced performance, its unique response characteristics require tuning of other hardware components that could be considered to be beyond the normal tuning range for that of a conventional suspension.

As vehicle development timelines continue to shorten, it is necessary for the full vehicle NVH engineer to be able to predict performance without actual prototypes. There has been significant advancement in the accuracy of finite element modeling techniques of trimmed bodies; however accuracy is still low in the road noise mid frequency range from 150-400Hz. Also, calculation times for these frequencies are long, with very large results files in some cases. To alleviate these limitations, a Hybrid approach has been used, where a finite element suspension and drive train model is coupled with a test based Frequency Response Function (FRF) model of the trimmed body. The predicted road noise level was compared to actual vehicle tests and exhibited excellent correlation.

The paper includes the development steps used in creating a station test apparatus (STA) and a description of the apparatus design. The purpose of this device is to simulate hydrogen vehicle conditions for the verification of gaseous hydrogen refueling station dispenser performance targets and hydrogen quality. This is done at the refueling station/vehicle interface (i.e. the refueling nozzle.) In addition, the device is to serve as a means for testing and developing future advanced fueling algorithms and protocols. The device is to be outfitted with vehicle representative container cylinders and sensors located inside and outside the apparatus to monitor refueling rate, ambient and internal gas temperature, pressure and weight of fuel transferred. Data is to be recorded during refueling and graphed automatically.

Customer satisfaction is one of the most important goals for car manufacturers in providing telematics services to their customers. Telematics is not merely a chance for additional revenue, but should be used to supplement value to an OEM's core business. Unfortunately most existing Telematics business models focus on revenue opportunities. However, the customer value of Telematics still resides in a conventional vehicle–related value model. Typical examples of killer applications are related to transportation, such as real time traffic information, vehicle operation information, vehicle diagnostic information and on–board entertainment. A new approach, which is well accepted by customers, is anticipated. The key solution is a combination of several challenges, such as the transformation of customer relationship management (CRM), optimum integration of existing infrastructure, and customer value proposition based on customers' essential expectations.

This research investigates the variation of pedestrian stance in pedestrian-automobile impact using a validated multi-body vehicle and human model. Detailed vehicle models of a small family car and a sport utility vehicle (SUV) are developed and validated for impact with a 50th percentile human male anthropometric ellipsoid model, and different pedestrian stances (struck limb forward, feet together, and struck limb backward) are investigated. The models calculate the physical trajectory of the multi-body models including head and torso accelerations, as well as pelvic force loads. This study shows that lower limb orientation during a pedestrian-automobile impact plays a dominant role in upper body kinematics of the pedestrian. Specifically, stance has a substantial effect on the subsequent impacts of the head and thorax with the vehicle. The variation in stance can change the severity of an injury incurred during an impact by changing the impact region.

Crucial specifications of an engine are spread widely in various subsystems, such as cooling system, intake and exhaust system, combustion system, etc. Well-informed design decision and optimized design solution cannot be reached without considering interactions among subsystems. Even though significant progresses on CAE technologies have been made to address physical and chemical phenomena in each subsystem, there are few studies in literature to model an engine with a reasonable coverage of subsystems in an integrated fashion. The necessity of such approach is justified from two aspects. Firstly, modifications in one subsystem could result in changes in other subsystems. Secondly, frequently due to experimental constraints or availability of prototypes which is the case for new engine design, boundary conditions for a subsystem of interest can only be obtained from integrated numerical simulations with other subsystems.

Improvement of engine cycle thermal efficiency is an effective way to increase engine torque and to reduce fuel consumption simultaneously. However, the extent of the improvement is limited by engine knock, which is more evident at low engine speeds when combustion flame propagation is relatively slow. To prevent engine damage due to knock, the spark ignition timing of a gasoline engine is usually controlled by a knock sensor. Therefore, an engine's ignition timing cannot be set freely to achieve best engine performance and fuel economy. Whether ignition timings for a multi-cylinder engine are the same or can be set differently for each cylinder, it is not desirable for each cylinder has big deviation from the median with respect to knock tendency. It is apparent that effective measures to improve engine knock toughness should address both uniformity of all cylinders of a multi-cylinder engine and improvement of median knock toughness.