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Measuring the real-world performance of emission control technologies is an important aspect in the development of advanced low-emission vehicles. In addition, data acquired from such measurements can be used to improve the accuracy of air quality predictive models. Honda has developed an on-board sampling/analysis system capable of measuring on-road emissions at ULEV levels and below. Ambient air can be analyzed simultaneously. This FTIR-based system can measure several species; this paper will focus on NMHC, NOX, and CO. Techniques were developed to address the challenges associated with acquiring accurate real-time data at concentrations below 1 ppm in an on-road vehicle. Validation studies performed with reference gases and vehicle exhaust indicate a very good correlation between the on-road analyzer system and classic bench methods for all target compounds. Dynamic studies performed by the University of California, Riverside, also show good correlation.

The new California LEV-II regulations for “near zero” evaporative emissions require a 75% reduction from current emission levels for light duty vehicles. To meet the challenge of satisfying these new regulations, there is an immediate need for an increased understanding of the sources of evaporative emissions. Hydrocarbon speciation by gas chromatography is a powerful analytical tool for determining the composition of complex hydrocarbon mixtures. Gas chromatography and gas chromatography/mass spectrometry were used to identify the volatile organic compounds (VOC) present in the evaporative emissions from a number of prototype and recent production model gasoline-fueled vehicles. For a “typical” evaporative emissions sample, more than 90% of the emissions were found to be fuel-type hydrocarbons.

In addition to PM total matter, PM size distribution is recently receiving increased attention because of the dependency of PM size on human health effects. Thus, PM size distributions and the emission behavior under various driving patterns are becoming important in diesel particulate emissions. Electrical Low Pressure Impactor (ELPI)_is a candidate to measure continuously, not only PM mass, but also particulate size distribution. Therefore, we investigated using ELPI to measure diesel particulate mass and size distribution, together with time series behaviors under various driving patterns. This study demonstrated the feasibility of continuous measurement of PM size distribution by means of an ELPI. The typical PM size distribution curve on weight base has a peak of 0.18 micrometer. The typical PM size distribution curve on number base has a peak of 0.11 micrometer. Engine load influences these characteristics.

In this paper, we present the results of an experimental study on particulate emissions of gasoline vehicles. The objective of the project was to investigate the particulate emissions on the basis of number and total mass and to gain experience in the influence of the sampling method on the results. The measurements were carried out with three passenger cars at a chassis dynamometer. Two vehicles with premixed combustion and one direct injection engine were tested at constant loads and driving cycles. For the aerosol sampling we used a standard CVS system, an ejector and a rotating disk unit. The samples were analyzed by SMPS and ELPI. Samples for gravimetric analysis were taken downstream of the CVS tunnel and from a mini tunnel. The results show that all three vehicles produce significantly less particulate in number and mass than a common diesel vehicle.

A light scattering photometer has been used to measure the diesel particulate emission from a vehicle to assess the capability of this instrument by comparing with the results from the traditional filter collection method and also with an opacimeter. Tests were conducted on a diesel vehicle mounted on a chassis dynamometer with its exhaust directed to a double dilution tunnel. Different types of test were carried out, including steady speed tests at different engine loads and transient tests. It was found that the correlation between the average particulate mass concentrations determined from the photometer and the filters changed with engine operating conditions. Comparison between the real-time outputs from the photometer and the opacimeter showed an excellent agreement in their particulate emission patterns measured during the transient tests. In conclusion, the photometer demonstrates a good potential in its application to diesel particulate measurements.

The environmental effects of particulate matter (PM) emissions from vehicles are an increasing concern to those concerned with air quality. A variety of technologies have been developed to measure exhaust particulates. The automotive industry generally uses the gravimetric method to quantify particulate emissions. This method uses a combination of a dilution tunnel and filter to collect PM from the diluted sample gas. The collected PM is later weighed on a microbalance. Because this technique is a batch measurement, it is not possible to determine at what point of an emissions test drive cycle the soot, soluble organic fraction (SOF) and total PM are emitted. A more accurate characterization of PM emissions will require real-time PM measurement under transient test conditions.

In a subproject of the aim to develop a worldwide certification procedure for heavy-duty on-highway engines (WHDC), the measuring technique for future low emitting engines was evaluated. One aspect is the introduction of partial flow dilution systems for the particulates measurement during transient test cycles instead of the currently required full flow dilution systems. This paper presents an investigation about the influence of sensitive sampling parameters on particulate mass and composition under steady state and transient engine operating conditions, and their effect on the correlation between partial flow and full flow dilution systems. The study has shown that the sampling parameters investigated have no or only minor influence on particulate mass and composition. Both partial flow dilution systems proved their transient capability by tracking the exhaust flow signal very well.

Flax (Linum usitatissimum L.) has supplied fiber for textiles for thousands of years. Recently, flax has been considered as a cost-effective alternative to glass in composites. New technology and separation techniques have lowered the costs to produce fibers that are more uniform in color, strength, length, and fineness and thus better suited for composites. Using redesigned techniques over those traditionally used in flax production, fiber separation begins at the farm using readily available agricultural equipment that has been tailored for flax harvesting. Rather than the expensive European harvest method of pulling stalks, rapid methods developed in the U.S. harvest flax stalks with a drum mower. Costly, specialized imported harvesters are no longer required to produce uniform fibers. Equipment is low cost, readily available and well understood by U.S. farmers. To further improve fiber quality, flax is not dew-retted, which depends on indigenous fungi to separate fibers.

This paper presents finite element analyses as well as static and fatigue performance of adhesive joints in an automotive composite structure. The automotive composite structure considered is a simply supported beam made by adhesively bonding a flat SRIM panel to the bottom of an SRIM hat section. Finite element analysis of such a beam showed the presence of significant peel stresses in the adhesive layer. Static and fatigue tests were then conducted with transverse tensile loads on adhesively bonded hat sections to determine the failure load in the peel direction. Finite element analysis of the transverse tensile loading condition identified the critical stresses in the adhesive and the failure mode expected in such joints. This study also examined the usefulness of combining adhesive and bolts to improve the joint performance.

Class “A” automotive parts with a 1.6 square meter surface area were produced using a new process of surface finishing/compression molding SFC (The Valyi SFC™ Process (1). In the process a precut Class “A” film finish blank was placed over the mold cavity of a vertical press. Molten plastic was extruded onto the film, reinforcing layers added, and the mold was closed. In this SFC process, the melt, deposited directly onto the film-backing layer, heats the film finish and causes it to become pliable for forming. This process eliminates the need for painting and produces large parts at low clamp forces. This paper reports the materials and process that were used to produce full sized development parts that demonstrate the capability for production of large structural panels such as roof tops, hoods, or trunk lids. In order to achieve the strength and stiffness requirements, continuous fiber reinforcements were moled into the parts.

Glass-mat-thermoplastic (GMT) composites are frequently used in structural applications in the automotive industry. Typically, these materials are flow molded in a compression press and weigh 4000 - 4900 g / m2. In this paper, we present the development of low-density (700 -2000 g / m2), long-fiber GMT composites for applications in headliner and other interior components. The new thermoplastic headliner materials offer several advantages over existing headliner materials, including low weight and cost; high rigidity at elevated temperatures and high humidity; faster cycle time; recyclability; design flexibility; a more environmentally friendly production method; and reduction of raw material inventory compared to existing processes. In this paper, we will discuss the mechanical and acoustical properties of this new headliner material and compare it with current headliner material substrates.

Blending polypropylene (PP) with materials such as rubber or filler creates compound PP, which is widely used in auto parts because of its balanced physical properties, formability, and cost performance. Recently non-painting of parts, namely coloring the raw materials, is being investigated as a method of reducing the cost of exterior parts which have conventionally been painted to match body colors, which are mostly metallic now. However flow marks often form in long injection molded parts such as the side protection molding, causing remarkable decreases in exterior appearance quality. This research investigates the influence of metallic coloring of PP material (blending PP and metallic pigment) factors on flow marks, as well as countermeasures for those causes of flow marks. PP and metallic pigment characteristics were the factors investigated to evaluate flow mark level.

Recent growth in automotive applications of magnesium die cast alloys has made the refining and recycling of magnesium scrap a key issue for the automotive and magnesium industries, if growth is to continue. Today, with only a few exceptions, commercially refined and recycled alloy is produced using a variety of flux-based processes. However, fluxless refining, has been the focus of growing interest, particularly for the in-house refining of scrap by the die cast producers. This paper summarizes the results of a study conducted to better understand the behavior of non-metallic contaminants in scrap melts and the requirements for their separation, using argon sparging. Brightness measurements were used to experimentally determine the distribution of non-metallic contaminants within scrap melts both before and after argon treatment.

Creep tests under three-point bending loading were conducted at elevated temperatures for long glass fiber reinforced polypropylene in order to examine the effect of maleic anhydride modification for polypropylene matrix on the creep resistance. The high acid modification (1 wt%) significantly reduces the creep deflection at both low and high sustained loads. The residual tensile strength after 1000 hours creep also increased with an increase of maleic anhydride content. AE observation indicating an occurrence of debonding decreased with increasing acid density. The fractured surfaces show that the interfacial strength between glass fibers and matrix can be increased owing to an increase of maleic anhydride fraction.

Applications of magnesium-based alloys to transmission and underhood automotive components have been limited by creep and bolt-load relaxation. A further concern is the relative expense of Mg alloys, such as AE42, that contain rare earth elements. These alloys still fall short of the performance of 380 Al. A new family of low-cost Mg alloys (ZAC) containing Zn, Al, and Ca has been developed and reported to approach AE42 and to outperform 380 Al; however, it exhibits castability concerns in die casting. This study was designed to evaluate the performance of semi-solid injection-molded (Thixomolded®)1 ZAC8506 bolt-load retention samples at temperatures up to 175°C. The Thixomolding® process has been reported to markedly improve the creep resistance of AZ91D as the volume fraction of solids is increased. The processing conditions were selected to produce bolt-load retention samples having solid fractions of 6% to 37% primary alpha.

The hatchback of Volkswagen's 3 liter car (3 l fuel consumption per 100 km) consists of an inner component of die casting magnesium (AM50) covered with an aluminum panel from the outside. This hybrid design requires a new manufacturing process: The pre-coated magnesium part will be bonded and folded with the bare aluminum part. Corrosion protection is provided by an organic coating system which both protects against general corrosion and galvanic corrosion. The corrosion of the Al / Mg sandwich has been examined with hybrid samples which are similar to the hatchback. Several powder coatings (epoxy resin, polyester resin, hybrid resin), wet paints and cathodic electro-coating paints of different thicknesses and compositions have been applied to the magnesium part. They show that only powder coating provides adequate protection. Galvanic corrosion at the points of attachment of the hatchback might be possible (for example the bolted joint of the hinge).

The increased use of magnesium die-castings in structural automotive components dictates the con-tinuing need for relevant and reliable data. There is virtually no literature relating to magnesium fatigue under corrosion environments. The purpose of the present study is to investigate the effect of an ‘Anomag’ coating on the fatigue and corrosion fatigue performance of magnesium alloys. The coating - ‘Anomag’, is produced by an anodising method and gives excellent corrosion resistance in chemical media. Standard Charpy test specimens of AM50A (50mm × 10mm × 10mm) with smooth surfaces were used for fatigue testing using the three point bending method. S-N curves were determined for uncoated (die cast surface), 5μm and 25μm thick coatings and 5μm and 25μm coatings with organic sealing. The environments adopted were natural seawater, tap water and air. Fatigue test specimens were characterised by X-ray radiography and SEM fractography before and after fatigue testing, respectively.

The use of die cast magnesium for automobile transmission cases offers promise for reducing weight and improving fuel economy. However, the inferior creep resistance of magnesium alloys at high temperature is of concern since transmission cases are typically assembled and joined by pre-loaded bolts. The stress relaxation of the material could thus adversely impact the sealing of the joint. One means of assessing the structural integrity of magnesium transmission cases is modeling the bolted joint, the topic of this paper. The commercial finite element code, ABAQUS, was used to simulate a well characterized bolt joint sample. The geometry was simulated with axi-symmetric elements with the exact geometry of a M10 screw. Frictional contact between the male and female parts is modeled by using interface elements. Material creep is described by a time hardening power law whose parameters are fit to experimental creep test data.

This paper provides a review of the fatigue properties reported in the open literature for die cast magnesium-based alloys. Recently developed fatigue data, in the form of stress versus number of cycles to failure for bending fatigue (R=-1), are presented for die cast AM60B and AZ91D alloy specimens with thicknesses between 1 and 10 mm. The effects of specimen thickness and macrostructural features, such as porosity distributions and surface features (parting line and ejection pin marks), on the fatigue data are discussed.

This paper describes the high-pressure die castability assessment of two high temperature magnesium alloys, AE42 and the AC series alloy. AE42 is a commercially available alloy. Results showed that AE42 was a castable material for use in high-pressure die casting applications, including large transmission components. AE42 was determined to have similar operating/manufacturing costs if produced in equivalent volumes to AZ91D. The AC series alloy is an experimental alloy comprised of AM50 combined with small percentages of calcium (Ca). It was found that the castability of the AC series alloy decreased with increasing calcium content. Over 0.3% calcium content yielded poor castability performance. Selected mechanical and corrosion properties of AZ91D, AE42, AM50 and the AC series alloys were also explored.