Revolution Fuel-Cell Vehicle（body part）
1. Introduction
1.1 Revolution Fuel-Cell Vehicle profile
In recent years,the rapid development and commercialization of fuel-cell vehicle propulsion swept the whole word,and its energy efficient and zero emission or near-zero emissions,good environmental performance,making the development of hot spots of today's word energy and transport sectors. With rhe active participation of major international car manufacturers and oil giant,from the capital to technology,has invested heavily, fuel cell vehicles have been out of the lab,began commercial journey.Many experts are optimistic that fuel-cell vehicles will lead to a revolution in the automotive industry,and eventually replace the traditional diesel locomotive into the mainstream.
The Revolution fuel-cell concept vehicle (Figure1.1)was developed internally by Hypercar to demonstrate the technicalfeasibility and societal, consumer, and competitive benefits of holistic vehicle design focused on efficiencyand lightweighting. It was designed to have breakthrough fuel economy and emissions, meet U.S. andEuropean Motor Vehicle Safety Standards, and meet a rigorous and complete set of product requirements fora sporty five-passenger SUV crossover vehicle market segment with technologies that could be in volumeproduction at competitive cost within five years (Figure1.2).
Figure 1.1 The Revolution fuel-cell concept vehicle
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Figure 1.2 Photo of full-scale model of Revolution and package layout drawings
1.2 Revolution Fuel-Cell Vehicle advanced technology
The Revolution combines lightweight, aerodynamic, and electrically and thermally efficient design with a hybridized fuel-cell propulsion system to deliver an unprecedented combination of features:
? Seats five adults with a package similar to the Lexus RX-300 ? 1.95-m3 cargo space with the rear seats folded flat
? 2.38 L/100 km (42 km/L, 99 mpg) using compressed 345-bar gaseous hydrogen fuel ? 530-km range on 3.4 kg of hydrogen ? Zero tailpipe emissions
? Accelerates 0–100 km/h in 8.3 seconds ? No damage in impacts up to 10 km/h
? All-wheel drive with digital traction and vehicle stability control
? Ground clearance adjustable from 13–20 cm through a semi-active suspension that adapts to
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load, speed,
location of the vehicle’s center of gravity, and terrain
? Body stiffness and torsional rigidity 50% higher than premium sports sedans ? Designed for a 300,000+-km service life
? Modular electronics and software architecture and customizable user interface
? Potential for the sticker price to be competitive with the Lexus RX300, Mercedes M320, and the BMW X5 3.0, with significantly lower lifecycle cost.
How is this achieved? Through careful whole-system design that integrates several advanced technologies at once in synergistic ways. An overview of some of the technologies in the Revolution can be found in Figure1.3 and background information is available in [1.4, 2.1, 2.2, 2.3].
Figure1.3 Technologies within the Revolution
1.3 Lightweight design
Every system in the Revolution is significantly lighter than conventional systems (Table 1.1 and Figure1.4).Different techniques were used for each system to achieve such weight savings. The body structure achieved nearly 60% mass reduction versus steel by using a combination of carbon-fiber composites, aluminum, and unreinforced thermoplastic.
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Carbon-fiber composites were used in the passenger safety cell and in dedicated composite energy absorbing members. Aluminum was used primarily in a front-end sub-frame, and unreinforced composite panels form the vehicle’s skin (Figure 2.1). The aluminum subframe and plastic skin are made with standard production techniques and will thus not be discussed in detail here.
Table 1.1 Mass comparison of Revolution with a conventional benchmark vehicle
Figure1.4 Mass pie charts
2. Composite Safety Cell Structural Design
The overarching challenge to using lightweight materials is cost-effectiveness. As carbon fiber composites cost significantly more per kilogram and per unit stiffness than steel, cost savings must be found in the structural design and manufacturing methods in order to make
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composites economically feasible. The design strategy that Hypercar employed was four-tiered:minimizing the total amount of material (and its corollary:ensuring most effective use of the material used) through concentrated, highly effective use whenever used;simplifying assembly, tooling, parts handling, inventory, and processing costs through design; integrating as much functionality into the structure as was practical; and employing a novel manufacturing system for the fabrication of the individual parts. Several features of the design that support this strategy are described below. 2.1 Design features 2.1.1 Part consolidation
The primary structure is illustrated in Figures2.1 and Figures 2.2. It is composed of fourteen major parts and 62 total parts—65% and 77% fewer parts than in the equivalent portion of a conventional stamped steel BIW, respectively. Each major part in the composite safety cell is joined using a patent-pending blade and clevis fully bonded joining technique that is strong, robust, and self-fixturing. Together, the small number of parts and the joint design simplify assembly, as just a few parts must be held together until the adhesive bond sets up, without the need for complex fixtures.
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