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In this paper, a 1-D refined driveline model in AMESIM was built up, for a P2.5 topology PHEV. The model includes detailed engine, damper, dual clutch transmission, differential, motor, half-shaft, wheel, body, suspension, powertrain mounting and powertrain rigid body, The objective of the simulation is to predict torsional vibration induced vehicle NVH response under different driving scenarios. Firstly, the torsional vibration modes were predicted, and the critical modes were identified. This enabled a good understanding of modal alignment, identification of countermeasures and provide feedback to other engineering teams in the early stages of vehicle development.

The formation of fuel film in the combustion cylinder affects the mixing process of the air and the fuel, and the process of the combustion propagation in engines. Some models of film evaporation have been developed to predict the evaporation behavior of the film, but rarely experimental results have been produced, especially when the temperature is high. In this study, the evaporation behavior of the film of different species of oil and their blends at different temperature are observed. The 45 μL films of isooctane, 1-propanol, 1-butanol, 1-pentanol, and their blends were placed on a quartz glass substrate in the closed temperature-controlled chamber. The shape change of the film during evaporation was monitored by a high-speed camera through the window of the chamber. First, the binary blends film of isooctane and one of the other three oils were evaporated at 30 °C, 50 °C, 70 °C and 90 °C.

Plug-in hybrid electric vehicles (PHVs) consume both fossil fuel and grid electricity, which imposes emission testing challenges on the current constant volume sampler (CVS) test method. One reason is that in the charge-depleting cycle, PHVs having all-electric range operate the engine for a small portion of the traction energy need, causing the CVS to overdilute the exhaust gas. The other reason is that the dilution factor (DF) in the EPA calculation has an error caused by ignoring the CO₂ concentration in ambient air. This paper evaluates these challenges by testing a Toyota PHV on the industry standard CVS system combined with additional continuous sampling methodology for continuous diluents, smooth approach orifice (SAO) measurement for ambient air flow, and fuel flow meter (FFM) measurement for fuel consumption. The current EPA DF can produce an error resulting in higher mass calculation.

Progressive stamping is an important manufacturing process in making automotive parts. Springback and static loading performance are two critical concerns in the part development. An accurate FE-based prediction on springback and static loading performance could foresee and avoid costly pitfalls in future part development. A bracket, which has tight tolerance and loading performance requirement, is chosen for this study. Implicit and explicit solutions, two major algorithms for solving the FEM motion equations, are used to simulate progressive forming process, which is composed of rib embossing and multiple bending. The springback effect is predicted on the ‘part’ formed by both implicit and explicit solutions. Measurement on the physical part shows the implicit solution can provides a more accurate prediction on both the thickness and springback.

In automotive body manufacturing, there are two processes are often applied, Nominal Build and Functional Build. The Nominal Build process requires all individual stamping components meet their nominal dimensions with specified tolerances. While, the Functional Build process emphasizes more on the tolerances of the entire assembly as opposed to those of the individual stamped parts. The common goal of both processes is to build the body assemblies that meet the specified tolerances. Although there is strict tolerance specified for individual stamping parts the finished stampings frequently are released to assembly process with certain levels of dimensioning deviations, or they are within the specified tolerances but require heavy clamping during assembly. It is of high interest to predict the dimensional deviations in the stamping sub-assembly or body-in-white assembly process.

One type of TiO2 nanoparticles modified by stearic acid was prepared by sol-gel method and its structure was characterized using Laser Particle Analyzer (LPA) and Freeze-Etching Electron Microscopy (FEEM). To evaluate the benefits of the nanoparticles used as substitute for sulfurized olefins in gear oils, the tribological properties of a mixture of TiO2 nanoparticles with a S-containing additive in base oil were investigated using four-ball tribotester. The experimental results show that there are some synergistic effects between the two additives. In addition, the function mechanism of TiO2 nanoparticles in the tribological process was elucidated by the use of X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM).

Studies in an Angular Stretch Bend Test (ASBT) have demonstrated that the failure location moves from the side wall to punch nose area. This occurs as the R/T ratio decreases below a certain limit and applies to most low carbon steels with the exception of Dual Phase (DP) steels. Such behavior in DP steels indicates that bending effects have a severe impact on the formability of DP materials. Therefore, the traditional criterion using the forming limit curve (FLC) is not suitable to assess the formability at punch radius areas for DP steels due in part to its uniqueness of unconventional microstructures. In this paper, a new failure criterion, ‘Bending-modified’ FLC (BFLC), is proposed by extending the traditional FLC using the “Stretch Bendability Index” (SBI) concept for the stretch bendability assessment.

The automotive industry is rapidly implementing computer simulation in every aspect of their processes mainly to decrease the time required to bring new models to market. Computer simulation can also be used to reduce the cost of vehicle development and manufacturing. A major portion of the manufacturing cost associated with automotive stamping lies in the process design, build and tryout of production dies and in automation of the transfer equipment. Press home-line tryout is largely a trial-and-error process relying heavily on the skills and experience of tool and die makers. To reduce this dependence on human skills and effort, press-line simulation can be effectively utilized to verify the design accuracy thereby reducing the changes needed to rework the production die/tool. The entire press-line with all its complete accessories can be modeled and checked for design errors similar to the try-out conducted in the production plant.

Springback study on a Dodge Ram fender outer panel is detailed in this paper. A simple measurement fixture is designed for the panel, wherein non-contact laser scan technology is applied The measurement data are compared with the original CAD design surface and deviation contour maps are obtained. Consistency of measurement is studied at different sections among three samples. Details of FEA simulations are outlined. The comparison between measurement and simulation prediction is summarized. A method to describe the consistency of measurement and the accuracy of simulation prediction is proposed. The targets for measurement consistency and simulation accuracy are verified. A sensitivity analysis is also performed to investigate various simulation input parameters.

With the increased application of high strength steels in automotive body-in-white parts for weight reduction purposes, more emphasis is focused on springback as a major problem in stamping operations, in addition to panel breakage and wrinkling. Computer simulations using the finite element analysis (FEA) have been used to predict springback during early stages of die development processes to minimize potential springback related problems in production. However, the reliability of the springback simulation results relies directly on the accuracy of stress distributions from the forming simulation. Its complexity has brought many challenges not only to engineers and researchers in areas of FEA development and material modeling but also to FEA code end users. It is shown from this study that the springback simulation results vary with the yield criterion used in the forming simulation.

Draw simulation of automotive panels generally consists of two steps: binder wrap and punch contact. The binder wrap simulation while providing the necessary initial conditions for the ensuing punch contact simulation, is itself practically important. For instance, one can evaluate the binder design by examining whether the sheet shape inside the die cavity is buckle-free and/or the sheet on the binder is severely wrinkled. The physical process involved in the binder wrap is dominantly quasi-static and complex as it involves contact, friction and buckling phenomenon. Current binder wrap simulation in the automotive industry has been mainly carried out either using proprietary software or dynamic explicit codes with slow speed. This paper presents implicit-static finite element results using ABAQUS/IMPLICIT Code on the binder wrap of several doubly curved laboratory binders and comparisons with test data. Good correlation was obtained.

Although numerical simulation techniques for sheet metal forming become increasingly maturing in recent years, prediction of springback remains a topic of current investigation. The main point of this paper is to illustrate the effectiveness of a modelling approach where static implicit schemes are used for the prediction of springback regardless whether a static implicit or dynamic explicit scheme is used in the forming simulation. The approach is demonstrated by revisiting the 2-D draw bending of NUMISHEET'93 and numerical results on two real world stampings.