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The high costs of prototyping, revisions, and production tooling, with a higher emphasis on quality, concurrent with demands for miniaturization, higher-density packaging, stricter performance, and a shortened product development cycle, have led to the development of advanced analysis techniques that address the performance issues associated with failure prevention in automotive connectors. Because of the complex material and geometric nonlinearity demands in performance, traditional calculations are inadequate, and new methods, utilizing finite element analysis techniques were developed. These highly specialized analysis techniques will enable the designer and engineer to predict connector performance with a high degree of confidence. Concurrent with concept designs, structural analyses (in the areas of assembly, disassembly, and terminal retention) must be done prior to design release.

Utilization of new technologies, such as LEDs, light guides, and electro-luminesence (EL), in courtesy lighting offers promising opportunities in styling, packaging, and functionality. Although these lamps are not as strictly regulated as other automotive lighting, considerable investigation is required to meet the desired styling and performance. In this paper we present the results of a study on running board lighting. This investigation was used to guide development of external courtesy lighting, where direct light, reflected light, contrast, and directionality are all design considerations.

This paper discusses the optical design of motor vehicle head lamps using the new federal visual optical aim requirements. Methodology for using filament images from a head lamp reflector to create the required sharp gradient for visual aimable lamps is presented. The paper discusses hardware tolerance factors which would degrade a sharp cut-off, and methods are reviewed for accounting for and designing robustness against the tolerance factors. Hardware results are shown for designs using the techniques described in the paper.

This paper will address several critical aspects of bumper system performance, including vehicle damage protection and crash-severity sensing considerations, energy-absorption capacity and efficiency, and low-speed impact consistency and sensitivity to temperature changes. The objective is to help engineers and designers establish a realistic perspective of the capability of the various technologies based on actual test performance. The scope of the evaluation will include a comparison of several bumper-beam material constructions when subjected to a 16-km/hr swinging barrier impact over a range of temperatures the bumper could see in service (-30 to 60C).

The first single-piece, injection-molded, thermoplastic, front bumper for a light truck provides improved performance and reduced cost for the 1997 MY Explorer® Ltd. and 1988 MY Mountaineer® truck from Ford Motor Company. Additionally, the system provides improved impact performance, including the ability to pass 5.6 km/hr barrier impact tests without damage. Further, the advanced, 1-piece design integrates fascia attachments, reducing assembly time, and weighs 8.76 kg/bumper less than a baseline steel design. The complete system provides a cost savings vs. extruded aluminum and is competitive with steel bumpers.

Over the last decade, on small- and medium-size passenger cars, a new class of front bumper - injection or blow molded from engineering thermoplastics - has been put into production use. These bumper systems provide full 8-km/hr federal pendulum and flat-barrier impact protection, as well as angled barrier protection. Thermoplastic bumpers, offering weight, cost, and manufacturing advantages over conventional steel bumper systems, also provide high surface finish and styling enhancements. However, there remain questions about the durability and engineering applicability of thermoplastic bumper systems to heavier vehicles. This paper presents results of a preliminary study that examines the durability of thermoplastic bumpers drawn from production lots for much lighter compact, and mid-size passenger cars against baseline steel bumper systems currently used on full-size pickup truck and sport-utility vehicles (SUVs). Bumpers were subjected to U.S.

This paper presents results from a series of tests that address safety related issues concerning vehicle glazing. These issues include occupant containment, head impact injury, neck injuries, fracture modes, and laceration. Component-level and full vehicle crash tests of standard and polycarbonate non-windshield glazing were conducted. The tests were conducted as part of a study to demonstrate that there is no decrease in the safety benefits offered by polycarbonate glazing when compared to current glazing. Readers of this paper will gain a broader understanding of the tests that are typically conducted for glazing evaluation from a safety perspective, as well as gain insight into the meaning of the results.

The purpose of this paper is to discuss design methodology, manufacturing considerations, and testing proveout for a prototype gas-assist-molded, energy-absorbing, glovebox door program. The design used a single gas pin mounted in a multiple-gas-channel component and an internal gas manifold to form an efficient energy absorbing system. The end goal for the development program was to manufacture a glovebox door in a system that could meet the customer's targets for cost, surface appearance, and safety considerations without degrading function and fit. This paper will discuss the ability of a design methodology to predict actual component performance using engineering calculations, analytical tools, and prototype testing/molding during the development.

The formulation of injection moldable thermoplastics with small loadings of graphite nanotubes provides sufficient conductivity in molded parts to allow for use in electrostatic painting applications. Normally, plastic parts need to be painted with a conductive primer prior to the electrostatic painting of base and clear coats. The use of conductive plastics eliminates the need for the priming step, and improves paint transfer efficiency and first pass yield. These elements provide obvious savings in materials and labor. What is less obvious, however, is the dramatic positive environmental impact that can occur through the reduction in emissions of volatile organic compounds (VOCs). Graphite nanotube technology provides advantages over other technologies such as conductive carbon black. In order to reach the percolation threshold for conductivity in carbon-black-containing resins, the loading of carbon black required tends to embrittle the polymer.

Thermoplastic body panels are emerging in the industry as automotive manufacturers seek to design for advanced aerodynamic styling, lower weight, and cost effective vehicles. To best exhibit the advantages of GE thermoplastic resins in these applications, an extensive study has been completed to demonstrate the impact performance of thermoplastic body panels in the field based on the current success with the Buick LeSabre T-Type, Buick Reatta, and the Cadillac Deville and Fleetwood models using NORYL GTX® 910 resin fenders. This study provides a “real life” scenario of the advantages of thermoplastics compared to steel in body panel applications.

In the automotive lighting industry, car manufacturers (OEMs) require that lamps pass vibration resonance test. Failure to pass this test means that the lamp cannot be delivered to the customer. Resonant frequency is a direct cause of lamp failure due to large deformations of lamp components at a specific frequency. Resonance tests can be estimated experimentally using a vibration machine or numerically utilizing finite element analysis software. These methods estimate the resonance of the lamp after the lamp is fabricated or the complete lamp model is created on the CAD software. The objective of this paper is to teach the development of a prediction tool to estimate the resonant frequency of lamps before fabricating the lamp or creating the model on the CAD system. Design of computer experimentation (DOCE) methodology has been utilized to identify the significance level of the parameters involved to estimate the resonant frequency of a lighting system.

Basic automotive steering wheel armature design has been largely unchanged for years. A cast aluminum or magnesium armature is typically used to provide stiffness and strength with an overmolded polyurethane giving shape and occupant protection. A prototype steering wheel armature made from a unique recyclable thermoplastic eliminates the casting while meeting the same stiffness, impact, and performance criteria needed for the automotive market. It also opens new avenues for styling differentiation and flexibility. Prototype parts, manufacturing, and testing results will be covered.

Electrostatic painting of exterior body components is considered standard practice in the automotive industry. The trend toward the use of electrostatic painting processes has been driven primarily because of environmental legislation and material system cost reduction efforts. When electrostatically painting thermoplastic body panels, side by side with sheet metal parts, it is imperative that the thermoplastic parts paint like steel. Electrostatic painting of thermoplastics has traditionally required the use of a conductive primer, prior to basecoat and clearcoat application. The use of conductive plastics eliminates the need for this priming step, while improving paint transfer efficiency and first pass yield. These elements provide an obvious savings in material and labor. The most significant benefit, is the positive environmental impact that occurs through the reduction in the emission of volatile organic compounds (VOC's).

Automotive lighting devices with reflective surfaces require high reflectivity for light collection and optimum photometric efficiency. The reflective surface is commonly aluminum applied by physical vapor deposition (PVD), i.e. an evaporative process or sputtering. The design and process of some reflective surfaces are such that certain areas of the target do not receive sufficient aluminum coating thickness. Reduced coating thickness results in decreased optical efficiency, and has led to increased thermal demands on the thermoplastic substrate. This paper seeks to quantify how reflectivity and substrate temperature are dependent on the thickness of the PVD metal coating, and thermal simulation tools are used to predict lamp temperatures for varying coating thickness of the reflective surface.

Drawing from previous studies published in SAE, a software program describes physical progress of water intrusion into or released from a lamp assembly. This program, based on test data, calculates condensation quantity and clearing time. It calculates moisture exchange between a lamp assembly and ambient, considering the moisture contained in the air inside of the lamp and moisture stored on the wall surface or in the materials. This program is applicable to different scenarios, such as initial humidity conditions of a lamp assembly, lamp size, type, venting type and test performance specifications. The significance of the program application in guiding test performance will also be addressed.

Automotive interiors are undergoing rapid transformation with the introduction of invisible PSIR integral systems. This styling trend requires continuous class A surface for the Instrument Panel (IP) and introduces complexities in the design and analysis of PSIR integral systems. The most important criterion for airbag doors is that it must open as intended, at the tearseam, within the deployment temperature range and without fragmentation. Consequently it is imperative that in analytical simulations, the finite element model of the tearseam is accurate. The accuracy of the model is governed by (a) optimal level of refinement, (b) surface geometry representation and (c) material model. This paper discusses modeling methodology for tearseams with respect to mesh refinement and the effect of geometry.

The evolution toward the use of electrostatic painting processes has been driven primarily by environmental legislation and efforts to improve efficiencies in the painting process. The development of conductive substrate material compliments the industry trend toward a green environment through further reductions in emissions of volatile organic compounds during the painting process. Traditionally, electrostatic painting of thermoplastics requires that a conductive primer be applied to the substrate prior to topcoat application. The conductive polymer blend of polyphenylene ether and polyamide provides sufficient conductivity to eliminate usage of conductive primers. Additional benefits include improved transfer efficiencies of the primer and top coat systems, uniform film builds across the part, and improved painting of complex geometries.

Automotive exterior paint systems can significantly affect the impact performance of thermoplastic body panels. To utilize the benefits of predictive engineering as a tool to assist in the design and development of thermoplastic body panels, thermoplastic body panel materials have been characterized with typical automotive paint systems for use for finite element modeling and analysis. Paint systems used for exterior body panels can vary from rigid to more flexible, depending on the vehicle manufacturer's specifications. Likewise, thermoplastics for body panels vary in mechanical properties, primarily depending on the heat performance requirements of the application. To understand the effects of paint systems on impact performance of thermoplastic body panels, two different paint systems, representing “rigid” and “more flexible,” were evaluated on two body panel grades of thermoplastics with different mechanical properties.

Many LEDs are typically required to source sufficient light for automotive exterior applications. Maintaining even illumination requires the drive current to be well controlled for all the LEDs in an array. This can be challenging in the voltage driven automotive environment when dual level operation is desired, such as for combined stop and tail function. A current source in the form of an LED Driver Module (LDM) can be employed to drive the LED array. However, a passive resistor network may be capable of driving the LED array with a reduction in both cost and complexity when compared to an LDM solution. The advantages and disadvantages of various passive resistor network configurations for dual level operation will be examined.

The effect of water vapor transfer from plastic materials commonly used in automotive lighting assemblies can be experimentally measured. This is accomplished by isolating this phenomenon from other mechanisms effecting water vapor concentration in the lamp. Quantifying this effect helps to address design considerations for liquid water and water vapor egress in the lighting assembly. The relevance of the current moisture clearing type test required in the industry is discussed in light of the empirical results for this effect.