Over the past five years, the US Automotive Materials Partnership (USAMP) has brought together representatives from DaimlerChrysler, General Motors, Ford Motor Company and over 40 other participant companies from the Mg casting industry to create and test a low-cost, Mg-alloy engine that would achieve a 15 - 20 % Mg component weight savings with no compromise in performance or durability. The block, oil pan, and front cover were redesigned to take advantage of the properties of both high-pressure die cast (HPDC) and sand cast Mg creep- resistant alloys. This paper describes the alloy selection process and the casting and testing of these new Mg-variant components. This paper will also examine the lessons learned and implications of this pre-competitive technology for future applications.

The properties of aluminum alloys reinforced by ceramic nanoparticles (less than 100nm) would be enhanced considerably while the ductility is retained over that of the native alloy. The potential of bulk Al-based metal matrix nano-composites (Al MMNCs) cannot be fully developed for industrial applications unless complex structural Al MMNC components can be fabricated cost effectively, such as by casting. Reliable bulk Al MMNCs cannot be cast unless the nanoparticles can be dispersed and distributed uniformly in molten Al alloys. This paper investigates a high volume production method for high performance aluminum matrix nanocomposites, in particular, the application of high intensity ultrasonic cavitation in mixing and dispersing nano-sized ceramic particles in Al melts to cast bulk Al MMNCs for complex automobile structures. Nano-sized SiC particles have been dispersed in molten aluminum alloy A356 for casting. Micro/nano-structural study has been carried out and it validates a good distribution and dispersion of nano-sized SiC in the aluminum alloy matrix. With the optimized processing parameters, the mechanical properties of the aluminum alloy have been improved significantly.

When a new vehicle or a variant of an existing vehicle is to be launched, it is vital to decide whether the vehicle is going to meet the predetermined targets. Using warranty data or CAE models, it may be possible to identify components of various aggregates with selected conformance/performance objectives.We have developed a method, which identifies what should be the tolerances for the dimensions of components, so that the conformance/performance would be within the speculated tolerance band. When the relationship between the conformance/performance criterion and the dimensions of components is quantitatively unknown, we have employed Central Composite Design at the FEA level. This establishes an empirical relationship between the conformance/performance criteria and dimensions of the selected components.

A new exhaust system has been developed to cope with post-SULEV (Super Ultra-Low Emissions Vehicle) regulation by newly designed hardware of exhaust system. This paper will describe the various new technologies used for achieving the post-SULEV standards, such as Conicat (cone-type metal catalyst), dual-wall pipe, pipe-type metal catalyst, ultra thin wall monolith and HC trap system for the improvement of catalyst light-off time. The tested data on 2.0L SULEV vehicle indicate that Conicat(cone-type metal catalyst) and HC trap (hydrocarbon absorbing catalyst) have more positive characteristics, and are expected to show the enhanced HC reduction performance with the optimization of emission system.

The objective of this study is to study the soot layer density and permeability in wall-flow diesel particulate filters. Knowledge of the soot morphology as function of the operating conditions is important for the design and on-board control of Diesel Particulate Filters (DPFs).The experimental set-up relies on a specially designed soot loading procedure on single-channel cordierite filters. The experimental conditions simulate real-world as close as possible regarding the filtration velocity, temperature and soot quality, since the sampling is done in real exhaust. By cutting, weighing and imaging the single channel filters it is possible to measure with accuracy the soot layer thickness as deposited under different operating conditions. Combined with pressure drop measurements and modeling, it is further possible to evaluate the soot layer permeability.The density values obtained ranged between 25 and 100 kg/m3 and were found to depend on flow velocity, pressure drop and soot loading. In order to de-couple the above effects on soot morphology, an intra-layer model able to account for locally variable soot properties and soot compressibility was developed. After calibration…

In this paper, HCCI combustion characteristics of three typical high octane number fuels, gasoline, ethanol and methanol, are compared in a Ricardo single cylinder port injection engine with compression ratio of 10.5. In order to trap enough high temperature residual gas to heat intake mixture charge for stable HCCI combustion, camshafts of the experimental engine are replaced by a set of special camshafts with low valve lift and short cam duration. The three fuels are injected into the intake port respectively in different mixture volume percentages, which are E0 (100% gasoline), E50 (50% gasoline, 50% ethanol), E100 (100% ethanol), M50 (50% gasoline, 50% methanol) and M100 (100% methanol).This work concentrates on the combustion and emission characteristics and the available HCCI operation range of these fuels. What's more, the detailed comparison of in-cylinder temperature, ignition timing and other parameters has been carried out. Results show that ignition timing of M100 is advanced much more than other fuels and alcohols have better adaptive capabilities to lean combustion than gasoline within the attainable HCCI operation range. When fueling…

This paper is about the methodology of integration of CAD data ( 3 D Models ) with its corresponding product structure ( EBoM ) and also about the validation of various usecase scenario. The methodology describes how single user interface is used for carrying out CAD data management, Visualization and PDM activities in Teamcenter environment..The scope of this paper is restricted to the application of Teamcenter's API's, Pro*E Metaphase Interface, Catia Metaphase Interface developed w.r.t. third party CAD authoring tools like Pro* E & CATIA respectively.It also describes a walk through procedure right from creation of CAD data item to its vaulting to EBoM connectivity and other associated activities as under Model versioning & vaultingConversion of native CAD models to lightweight neutral format ( JT )Part & product StructureEngineering Change Management for handling Design changeDrawing management.

To have better confidence on CAE prediction of crashworthiness analysis, the process of verification and validation for the explicit finite element method is essential. Selected examples are presented to study the convergence behavior and the quality of the explicit finite element method for transient dynamics.For the axial vibration of a rod, the computed displacement and velocity, and the frequencies calculated by using Fast Fourier Transform achieve the optimal convergence rates when mesh is refined. For a clamped rectangular plate subjected to lateral load, the elastic deflection and rotation calculated by using Reissner-Mindlin plate element, achieve the optimal convergence rates within a range of thickness. For the motion excited by initial velocity, when the thickness is reduced however, the deterioration in convergence of velocity related terms is observed. For the high speed axial impact of structural components, with large plastic deformation, the convergence rate of some items below optimal value is observed, particularly when heavy contact occurs. With reduced thickness, deteriorated convergence is observed.

The goal of this study was to develop and validate a finite element (FE) model of the Polar-II pedestrian dummy. An upper body model consisting of the head, neck, shoulder, thorax, and abdomen was coupled with a previously validated model of the lower limb The viscoelastic material properties of the dummy components were determined from dynamic compression tests of shoulder urethane, shoulder rubber and abdominal foam. For validation of the entire upper body, the model was compared with NHTSA response requirements for their advanced frontal dummy (Thor) including head and neck pendulum tests as well as ribcage and abdominal impact tests. In addition, the Polar-II full body FE model was subjected to simulated vehicle-pedestrian impacts that recreated published experiments. Simulated head and pelvis accelerations as well as upper body trajectories reasonably reproduced the experiment. The results of the model validation indicate that the Polar-II FE model can be used as an effective tool to evaluate the full body response of the Polar-II dummy and to evaluate the efficacy of future modifications to the dummy.

Elimination of a clamp force sensor from brake-by-wire system designs is strongly demanded due to implementation difficulties and cost issues. In this paper a new method is presented to estimate clamp force using the motor angular position of the actuator that can be sensed by an internal resolver. The estimator is a dynamic nonlinear model that is derived from a system identification approach where frequency domain analysis is merged with nonlinear compensation. The designed estimator is able to accurately track a wide range of sinusoidal, ramp and random clamp force signals. It is particularly tolerable to high speed cases as demanded by ABS controls. This paper is concluded with further investigation detailed that is necessary to ensure a robust clamp force estimator is developed.