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Automotive exterior body panels are a critical component of today's vehicle. They provide a surface for painting, offer the first line of defense against damage from accidents and the elements, and in most cases add to the overall stiffness of the vehicle. Despite small inroads from aluminum and polymer systems, steel remains the predominant body panel material. Of the alternatives, sheet molding compound (SMC) has been the most successful challenger. This paper examines the cost and market conditions affecting SMC today and in the near future. The impact on cost of SMC compression molding process improvements is assessed over a ten year period for a full body panel set. These results are compared to stamped steel as a function of annual production volume and other key factors. The result is a cost “crossover” point below which SMC has the lower cost.

Aluminum and polymer composites have long been considered the materials of choice for achieving mass reduction in automotive structures. As consumer and government demand for mass reduction grows, the use of these materials, which have traditionally been more expensive than the incumbent steel, becomes more likely. In response to this growing challenge, the international steel community has joined forces to develop the Ultra Light Steel Auto Body (ULSAB). The resulting design saves mass and increases performance relative to current steel unibodies. Although mass savings are not as dramatic as those achieved by alternative materials, this design offers the potential to be accompanied by a manufacturing cost reduction. The projected manufacturing piece and investment cost for the ULSAB are investigated using technical cost modeling. The results presented here examine the elements that contribute to the cost, including treatments for stamping, hydroforming, assembly and purchased parts.

In the past decade, the demand for and development of tailor-welded blanks (TWBs) has increased dramatically. TWBs help reduce body mass, piece count and assembly costs, while potentially reducing overall cost. IBIS Associates, Inc. has performed a cost analysis of tailor welded blank manufacturing through the use of Technical Cost Modeling (TCM), a methodology used to simulate fabrication and assembly processes. IBIS has chosen the automobile door inner panel for comparison of TWBs and conventionally stamped door inners with added reinforcements. Manufacturing costs are broken down by operation for variable costs (material, direct labor, utility), and fixed costs (equipment, tooling, building, overhead labor, maintenance, and cost of capital). Analyses yield information valuable to process selection by comparing cost as a function of manufacturing method, process yield, production volume, and process rate.

The Partnership for a New Generation of Vehicles (PNGV), a collaborative government-industry R&D program, has laid out and initiated a plan for a “Supercar” with the following specifications: a fuel economy of 80 miles per gallon (2.9 liters/100 km), size comparable to a midsize, four door sedan, equivalent function in other performance areas, and cost commensurate with that of today's automobile. Together, the performance and cost goals are formidable to say the least. The PNGV projects that a 50% mass savings in the “body-in-white” (BIW) is a necessary contribution to meet the 80 mpg goal. The two most likely materials systems to meet the mass reduction goal are aluminum and carbon fiber reinforced polymer composites, neither of which are inexpensive relative to today's steel unibody.

The painting of today's automobile incurs both economic as well as environmental costs. Using an approach called Technical Cost Modeling, this paper assesses the cost of painting a steel vehicle using a conventional solventborne painting technique and a UV cure alternative. The UV cure approach is found to have a cost advantage due primarily to decreased material, energy, and investment components. The cost of both systems is examined as a function of changing production volumes (and corresponding production rates) as well as first pass capability, with volume being found to be the more significant contributor. While the UV cure approach needs to be demonstrated at prototype and high volumes, it offers the potential not only for improved cost, but also significantly decreased environmental impact in the form of reduced volatile organic compound (VOC) solvent emissions.