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The application of crash durable structural adhesives in modern cars design, to improve the driving durability, the overall vehicle stiffness, the crash resistance and to make real light weight constructions feasible is significantly gaining in importance. 1-component systems are already introduced in the market and used in automotive industries. Usually the use of these bonds in automotive industries is limited by a relatively low wash off resistance in the pre-treatment tanks of the paint shop. If no additional actions are taken, there is a severe risk of wash off of the adhesives up to the partial loss in functionality. Respectively contamination of the pre-treatment tanks and aftereffects damage the surface of the coated cars. To avoid wash off a thermal process (oven) to pre-gel the adhesive in the flanges of the Body-In-White (BIW)- bodies before entering the pre-treatment utility is necessary. This is a save but cost intensive solution.

The diesel particulate filter (DPF) is a critical aftertreatment device for control of particulate matter (PM) emissions from a diesel engine. DPF survivability is challenged by several key factors such as: excessive thermal stress due to DPF runaway regenerations (or uncontrolled regeneration) may cause DPF substrate and washcoat failure. Catalyst poisoning elements from the diesel fuel and engine oil may cause performance degradation of the catalyzed DPF. Harsh vibration from the powertrain, as well as from the road surface, may lead to mechanical failure of the substrate and/or the matting material. Evaluations of these important validation parameters were performed.

Since their introduction in automobiles, polymeric materials have enabled designers and engineers to differentiate products based on performance attributes, mechanical response, aesthetics, and manufacturing techniques. A large segment of these applications utilizes polypropylene (PP) resins. One of the attractive features of PP polymers is the ability to tailor their mechanical, thermal and processing performance envelope via modification of their composition and the addition of fillers. Key to the successful application of PP resins in structural systems is the ability of designers and engineers to understand the material response and to properly model the behavior of PP structures upon different mechanical and thermal loading conditions.

To meet automotive legal, consumer and insurance test requirements, the process for designing energy absorption countermeasures usually comprises Finite Element simulations of the specified test. Finite element simulations are used first to see if there is a need for an Energy Absorption countermeasure at all and if so, what type, material and shape. A widely used class of energy absorption countermeasures in automotive interior applications is honeycomb extruded polypropylene foams (HXPP). Under compression, these foams exhibit a constant plateau stress until late densification. This enables these foams to minimize packaging space for a given amount of energy to be absorbed or maximize energy absorption for a given packaging space. Robust and easy to use isotropic CAE material models have been developed for HXPP, however the true material properties are anisotropic and such a material model could be necessary in some cases.

European car manufacturers and suppliers are currently stepping up the effort to develop solutions to meet pedestrian safety requirements, which will come into effect, starting in 2005. Numerous concepts, both active and passive, are being investigated to fulfil the pedestrian safety specifications, in addition to the many other limitations imposed on the front end of the car. All of them deal with the topic of energy absorption. Here, an approach to achieving a passive solution will be presented, describing the development of the ‘Virtual Stiffness Profile’ (VSP) to help identify the optimum balance of engineering and styling to meet the requirements. In this paper, specific emphasis is placed on the lower leg impact.

Splash and spray conditions created by tractor-trailer combinations operating on the Federal highway system have been studied and tested for many years with mixed results. Past events are reviewed briefly in this paper. In additional testing during 1983, using new state-of- the-art splash/spray suppressant devices, some encouragement was provided that these devices could work. The 1984 Motor Vehicle Manufacturers Association (MVMA) test program was designed to develop practicable and reliable test procedures to measure effectiveness of splash and spray reduction methods applied to tractor-trailer combination vehicles. Over 40 different combinations of splash/spray suppression devices on five different tractors and three van trailer types were tested. The spray-cloud densities for some 400 test runs were measured by laser transmissometers and also recorded by still photography, motion pictures, and videotape. On-site observers made subjective ratings of spray density.

Extending engine-oil-change intervals is of interest from the standpoint of reducing used oil disposal and reducing time and expense of maintenance. However, the oil must be changed before serious oil degradation and engine damage occur. Three variables which influence oil degradation were chosen for investigation: base oil composition (synthetic oil versus mineral oil), trip length (short trips versus long trips), and driving schedule (degrading an oil during a given type of service, then changing to another type of service without an intervening oil change). Analysis of oil samples taken throughout the testing program indicated that type of service (freeway compared to short trip) influenced oil degradation to a greater extent than oil type. That is, API SG-quality synthetic oil in short-trip service degraded faster than borderline SG-quality mineral oil in long-trip service.

Modular front-end carriers to pre-assemble front-end components such as cooling systems, lights, and bumper beam have been in production in different vehicles for several years. Compression molded or overmolded steel/plastic carriers have traditionally been used. The present paper explains the design, material options, and engineering optimization of a composite front-end carrier, which utilizes long glass fiber injection moldable resins and adhesively bonded steel reinforcements. Experimental evaluation of prototypes shows the system met the functional performance requirements at minimum weight.

Mechanical properties of as-rolled steels used in a vehicle vary with many parameters including gages, steel suppliers and manufacturing processes. The residual forming and strain rate effects of automotive components have been generally neglected in full vehicle crashworthiness analyses. Not having the above information has been considered as one of the reasons for the discrepancy between the results from computer simulation models and actual vehicle tests. The objective of this study is to choose the right material property for as-rolled steels for stamping and crash computer simulation, and investigate the effect of forming and strain rate on the results of full vehicle impact analyses. Major Body-in-White components which were in the crash load paths and whose material property would change in the forming process were selected in this study. The post-formed thickness and yield stress distributions on the components were estimated using One Step forming analyses.

Side mirror design optimization has been traditionally accomplished using an iterative design and testing process, often resulting in considerable costs in retooling operations, and causing significant delays in production. The ever increasing demand for high quality products has led major automotive companies to set high performance standards for side mirrors. These include structural, vibration, and aesthetic criteria, which affect the functionality and appearance of the mirror. The first two issues have been successfully addressed here using a fundamental design philosophy and a computer aided engineering approach. This approach has helped improve product quality, reduce the costs associated with redesign and retooling and minimize the development cycle time from concept to production.

A methodology to develop full-vehicle representation in the form of a finite element model for crashworthiness studies has been evolved. Detailed finite element models of two passenger vehicles - 1995 Chevy Lumina and 1994 Dodge Intrepid have been created. The models are intended for studying the vehicle’s behavior in full frontal, frontal offset and side impact collisions. These models are suitable for evaluating vehicle performance and occupant safety in a wide variety of impact situations, and are also suitable for part and material substitution studies to support PNGV (Partnership for New Generation of Vehicles) research. The geometry for these models was created by careful scanning and digitizing of the entire vehicle. High degree of detail is captured in the BIW, the front-end components and other areas involved in frontal, frontal offset and side impact on the driver’s side.

A new advanced ceramic material (ACM) has been developed and examined for diesel emission control systems, especially for diesel particulate filter (DPF) applications. Lab tests have shown that ACM possesses suitable mechanical and chemical properties for a durable DPF. Engine dynamometer tests have shown that a DPF made from ACM possesses high performance in the key application requirements of high filtration efficiency, low filtration back pressure, fast regeneration, and suitability for catalyst coating applications. The experimental results from this investigation demonstrate that a DPF made from ACM can be used for advanced diesel PM emission control systems, including potential four-way diesel catalytic converter systems.

In this paper, new event-based engine control algorithms utilizing more than one reference pulse per cylinder firing event are designed for improved engine spark timing control. These control algorithms, based on the cyclic nature of the internal combustion engines, can achieve more accurate estimation of crankshaft rotational speed and position than conventional algorithms. The application of these prediction algorithms to improve the accuracy of engine spark timing control is demonstrated using a dynamic engine simulation.

Recently, automotive engineers have been looking at rigid polyurethane foam systems for the advantages their application brings to vehicle design and performance. The benefits range from NVH management achieved through effective body cavity sealing and improved structural dynamics, to enhanced vehicle crashworthiness. These benefits can be realized through application of polyurethane foam systems designed for energy management. These systems offer multifunctional, low cost solutions to traditional approaches and can be modeled early in the vehicle design stage. In many cases, the overall vehicle mass is reduced as reinforcements are eliminated and/or sheet metal thickness is decreased. Dow Automotive has developed a family of water blown polyurethane foams specifically for these applications. Development has focused on foam systems designed for impact optimization, allowing OEM's to optimize the body structure content.

The application of two-component polyurethane (PU) foam materials for acoustical and structural performance enhancements in vehicle structures have increased significantly in the past ten years. The benefits include NVH management (through effective cavity sealing), body stiffness improvements and energy management in crash applications. These PU foams can either be pumped into body cavities in the OEM assembly plants (bulk applied) or can be pre-molded into Structural Foam Inserts (SFI) and installed in the body-shop prior to full frame assembly. The choice of application type depends on vehicle-specific requirements and assembly plant criteria. The chemistry, plant application and benefits associated with bulk PU foam has already been cited in previous work.1, 2, 3 This paper showcases BETAFOAM™ SFI technology developed by Dow Automotive that complements traditional bulk foam technology.

Diesel particulate filters (DPF) made from Dow's advanced ceramic material (ACM) have already demonstrated high filtration efficiency, low pressure drop, and high temperature performance capabilities. In addition to these advantages of the ACM-DPF, it has been found to be well suited for use in combination with various catalyst coatings while maintaining it's overall advanced performance over a broad range of catalyst loadings. Our recent studies on catalyzed ACM DPF demonstrate that the unique micro structure of ACM is able to maintain significant amount of catalyst and washcoats. The characteristics of the ACM DPF pressure drop versus catalyst washcoats loading have been fully investigated. With defined coating techniques, ACM DPF can be loaded with three times the amount of washcoat than can a Silicon Carbide DPF without significantly increasing the pressure drop.

This paper describes the application of pore-scale filtration simulations to the advanced ceramic material (ACM) developed for use in advanced diesel particulate filters. The application required the generation of a three-dimensional substrate geometry to provide the boundary conditions for the flow model. An innovative stochastic modeling technique was applied matching chord length distribution and the porosity profile of the material. Additional experimental validation was provided by the single-channel experimental apparatus. Results show that the stochastic reconstruction techniques provide flexibility and appropriate accuracy for the modeling efforts. Early investigation efforts imply that needle length may provide a mechanism for adjusting performance of the ACM for diesel particulate filter (DPF) applications. New techniques have been developed to visualize soot deposition in both traditional and new DPF substrate materials.

An experimental method for nondestructive estimation of damage in joints due to high mileage degradation in cars is presented. The method estimates damage by comparing transfer functions of the same car at zero and at high mileage. The potential of the method is demonstrated analytically using a three dimensional concept Finite Element Model (FEM) of a car body to simulate the transfer functions of this car body at zero and at high mileage. The results demonstrate that the method is effective for identifying the damaged joints as well as the relative degree of degradation.

Polyamide resins are well established within the automotive industry and are widely used in a range of demanding under-the-hood applications such as valve covers and air intake manifolds. In reality however, the disadvantages of conventional nylon products, such as excessive warpage and poor dimensional stability to name but two, make it increasingly difficult for engineers to produce the ever more complex parts demanded by new engine developments. In this paper we shall introduce a new range of modified Dow Polyamide resins that greatly reduce the above mentioned disadvantages. In comparisons with commercially available nylon 6 and 66 materials we shall illustrate improved warpage behaviour and lower moisture pick-up in combination with excellent chemical resistance to, for example, hot motor oil and ethylene glycol. In summation, examples will be provided to illustrate the improved utility of these new, modified Dow Polyamide resins.

Low density polyurethane foam, applied in general assembly, is being used as a replacement for rubber-based heat reactive baffles in automobile cavities to inhibit noise transmittance. Most chemically reactive urethane foam systems used in barrier applications are MDI-based (diphenylmethane diisocyanate). The use of classical MDI-based technology in assembly plants typically requires substantial levels of ventilation [1]. High capital and operating expenses associated with plant ventilation systems have hindered the growth of polyurethane technology. This paper describes benefits of using a low MDI polyurethane foam system in place of classical two-component MDI-based foam systems and conventional rubber-based heat reactive baffles. Severe industrial hygiene testing has indicated that ventilation requirements to use the low MDI foam system in assembly plants may be greatly reduced.