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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.

Automotive manufacturers are driving for improvement, creativity and innovation in vehicle systems in order to differentiate products in the global market. Progress in fuel efficiency, occupant safety, comfort, recyclable friendly pre-assembled modular systems, and novel manufacturing methods is difficult to achieve if no major departure from the traditional design, engineering, material mix, and assembly approaches is considered. More importantly, these benefits will not materialize unless the relationship between automotive manufacturers and suppliers changes, allowing suppliers to take a more active role in the vehicle development process. The present paper explores achievements made towards the development of new, innovative technologies to address simplification and overall performance improvements using non-traditional materials.

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.

Automotive body structures are developed to meet vehicle performance requirements primarily based on ride and handling, crashworthiness, and noise level targets. The body is made of a multitude of sheet metal stampings welded together. Other closures such as fenders, hood, doors and trunk lid are developed to match body interfaces, to contribute and participate in the overall vehicle response, and to meet the sub-system and system structural requirements. In order to improve performance and achieve weight reduction of the overall vehicle steel structure, new polymeric materials and treatment strategies are available to body structural engineers to optimize the response of the vehicle and to tune vehicle performance to meet specified functional requirements. If early integrated to the design cycle, these materials help not only improve the structural body response, but also decrease the weight of the integrated body structure.

Passenger protection to reduce fatality and injury rates is of critical importance worldwide. Side and head impact occupant protection requirements have been legislated both in North America and Europe. Even though the applicable legislation for each impact condition is different, the impact event poses similar functional requirements. Therefore, concept designs and methodologies for engineering optimization can be used interchangeably to develop countermeasures whether dealing with side or head impact crashworthy systems. The present paper outlines the use of a systematic approach that combines structural CAE simulations and Design of Experiments (DOE) for the optimization of the structural performance of crushable thermoplastic energy absorbers that are being used in door panels and upper interior trim. The use of DOE allows the evaluation of critical design and material parameters which affect the performance of the system.

The drive for lower weight instrument panels (IP) can be addressed with different design approaches. The first and more traditional approach is to substitute existing substrate materials with materials having a higher stiffness-to-density ratio. The second approach looks at the sub-system level where weight reduction is achieved through part integration. To exemplify this type of designs, examples of innovative knee bolster solutions are shown. The third and most radical approach is weight reduction at the system level. Alternatives to instrument panels that use traditional cross car beam structures will be presented. With these alternatives, hybrid and structural instrument panels can be developed in which weight reduction is achieved by part integration and by allowing plastic materials to fulfill a more significant structural role than in traditional IPs.

Fully-integrated structural instrument panels (IP) have been in commercial use in passenger cars, light trucks, and sport utility vehicles for some years now. They offer a cost-effective alternative to the more traditional IP construction that utilizes full-size cross car beams to achieve the structural stiffness and energy management required to meet Federal Motor Vehicle Safety Standard (FMVSS) 208 and corporate performance requirements. The natural evolution of interior designs demands an increasing level of integration of the different components in the interior of the vehicle. Therefore, the natural extension of current structural IP technology is to integrate the steering column subassembly, i.e., steering column and column support, and the heat, ventilation, and air conditioning (HVAC) unit into a modular pre-assembled system.

The increase in instrument panel design and functional performance requirements has resulted in a variety of structural architectures that have been utilized in different passenger vehicles, vans, and light trucks. Each architecture can be designed and engineered to meet corporate and federal requirements using different levels of integration, functionality consolidation, and assembly simplification. The present paper reviews three basic IP design architectures, i.e., traditional, hybrid, and structural, and discusses the performance requirement-functionality matrix in each case. Emphasis is given at explaining the role components play in the different architectures, defining their contribution to static, dynamic and crash performance and their relation to the overall assembly process and sequence. Performance and functionality requirements are linked to basic material characteristics that guide material selection for achieving design targets.

During driving, automobile and light truck occupants interface with almost all the components in the passenger compartment. These components are expected to provide not only ease of access to controls and comfort to the occupants, but also the necessary protection to decrease the likelihood of injuries during accidents. The passing of the revised Federal Motor Vehicle Safety Standard (FMVSS) No 201 is aimed at improving the overall safety of vehicle occupants during impact situations Amendments are specifically focused at improving the protection provided by the upper compartment components, i e, header, rail, pillar and roof trim panels, to the occupants' heads impacting at high velocities. The present paper reviews the requirements established by the revised federal legislation and the design and material options to meet the requirements, and describes a systematic approach for designing and engineering trim panels for head impact protection

Inner door panels provide the interface between the occupant and the vehicle side structure They have to meet aesthetic requirements in order to provide a continuous and harmonious flow between the forward components, i e, instrument panel and pillar trim, and the rear components in the occupant compartment, while meeting engineering and occupant protection requirements Occupant protection upon side impact has led to the use of a variety of supplemental devices sandwiched between the inner door panel and the inner sheet metal stamping The present paper discusses a different approach to meet side impact protection with a collapsible energy absorber that is molded in injection molded door panels, thus becoming integral to the panel itself This approach eliminates the need for assembly of an independent absorber cartridge simplifying the assembly of the door system and reducing the material mix that results when using thermoset polyurethane foam blocks with thermoplastic panels, thus facilitating the disassembly and recycle of the panel

The opportunity for composites in engine closure systems such as valve covers, oil pans, and timing belt covers is expanding rapidly. The primary driving forces are lighter weight finished components, integrated designs, improved isolation of engine noise, improved materials systems, and matured manufacturing processes for composite materials. Thermoset-based composite materials, particularly those based on high-temperature resistant epoxy vinyl ester matrices, offer improved performance with respect to thermoplastic and thermoset polyester-based composites and can be manufactured using different processing methods. This paper presents the current state-of-the-art design, engineering and optimization techniques for engine closure systems. The performance requirements of different systems such as valve covers and oil pans are explained in detail. Techniques for long-term structural stiffness evaluation, vibration performance assessment and noise transmission estimation are described.

Structural instrument panels are an excellent alternative to traditional constructions since they can provide substantial part consolidation, weight reduction, tool and cost savings, and manufacturing and assembly simplification. In structural panels, the main energy absorbing element for decelerating an unrestrained occupant is the plastic integrated retainer-structural duct. The role of the components in the instrument panel needs to be clearly understood for adequately engineering the system and properly selecting the polymeric material for optimum system performance in the different operating environments. The present paper discusses the performance of the structural instrument panel, the engineering and design requirements, and provides guidelines for selection of materials.

The evolution of the design of a laminated steel/composite bumper beam is presented. The composite beam replaces the steel front bumper system in the 89 Cadillac C-car sedan. Different design concepts were evaluated using CAE tools. The use of a thin steel cover plate on a composite substrate decreased the total weight of the system by over 50 %. Data from testing of prototypes shows that the energy performance of the laminated beam is as good as that of the original steel system for the different loading conditions.