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A Study of Optimal Automotive Materials Choice Given Market and Regulatory Uncertainty

出版	Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program, 2008
URL	http://books.google.com.hk/books?id=CI4ccgAACAAJ&hl=&source=gbs_api

註釋This present thesis hypothesized that the increasing demand for fuel-efficient vehicles, recently updated Corporate Average Fuel Economy (CAFE) regulation, and volatile U.S. sales markets may foreshadow a shift in the competitiveness of lightweight alternative materials relative to incumbent steels. To test this hypothesis, a novel automotive materials selection methodology was developed which evaluates the net present value (NPV) of vehicle projects by incorporating five integrated models: (1) an ADVISORbased vehicle performance model, (2) a market model that predicts expected annual sales, (3) a cost model that maps technology decisions and sales levels to fixed and variable costs, (4) a binomial lattice model of demand uncertainty, and (5) a regulatory model that mimics CAFE. The integrated model solves materials selection problems by optimization, using explicit simulation to find the set of materials choices for which the NPV of a vehicle project is maximized. A case study was developed to illuminate the competitive dynamics between incumbent steel and lightweight composite materials in two vehicle subsystems (body-in-white, closure set) and three vehicle markets (small car, mid-size car, luxury car). The results suggest that the value of acceleration improvements due to a lightweight materials enabled vehicle mass reduction is greater than the value of concurrent fuel economy improvements. When the value of acceleration improvements and fuel economy improvements are considered, the production volume at which it becomes economically efficient to switch from using composites to using steel shifts from the cost-competitive production volume to a higher one. The magnitude of this shift depends on the degree to which the car market values performance improvements and the rate at which composites become more costly than steel. Generally, more stringent CAFE policies were found to improve composite materials' competitiveness to a greater degree than the effects of demand uncertainty.