Hyper

A clean sheet approach to automotive design Thammy Evans of Hypercar Inc explains the company's approach to automotive design. From a clean sheet perspective it uses composites heavily throughout the vehicle, including the primary structural elements, to gain significant advantages in performance and cost.

N o one said it would be easy to make high volume composite

vehicles that are cost effective and do not compromise on perform-

ance, but Hypercar Inc has at least said it can be done. 'No compromise ' has been Hypercar's work ethic ever since it was founded in 1998 to build a high volume production, lightweight vehicle

that is super fuel efficient and uses the most modern technology and design techniques.

Making something simple is a complex process, whereas it is very simple to make something complex.

The result: a 99 mpg-equivalent (2.4 litres per 100 km) sport utility vehicle (SUV) crossover, with a composite

body/chassis structure, and powered by a proton exchange membrane (PEM) hydrogen fuel cell. After its first year of computer aided design (CAD) development and technology assessments, funded by a mere US$4.3 million, the full-scale showcase model, named the Revolution, shows off the sleek aero- dynamics of the design. Company CEO Jon DeVault, a long-time composites industry executive, witnessed the unveiling of the vehicle last year, and says the model has been well received in

54 REIIVFORCEDplastlcs September 2001

private and public showings across Europe and the USA.

Composites intensive Despite the excellent reviews of the vehicle's external design, however, the company 's main focus is on the in- ternal workings of the design's system innovations, which it refers to collect- ively as the ' foundat ion platform. ' Positioning itself as an advanced technology development company, the development team had to look at the vehicle as a whole system in order to capture savings in production costs that can not otherwise be gained

by conventional compartmental ized approaches.

Hypercar asserts that only by making the vehicle composites intensive, and by radically simplifying the design, it is able to make the desired improve- ments to the vehicle in terms of performance and fuel efficiency. The vehicle requires less power to move forward or to stop, and the drive train, suspension and steering mechan- isms shed considerable weight by not having to manage so much mass, and through the use of by-wire technolo- gies. Its design heralds the coming of drive by wire and makes long range

0034-3617/01/$ - see front matter © 2001 Elsevier Science Ltd. All rights reserved.

A clean sheet approach to automotive design

direct-hydrogen fuel cell vehicles immi-

nent ly possible. Hypercar produced the SUV

crossover as its showcase model after initial market research in the American market. The average US driver typically demands plenty of room inside the car, good acceleration, with the ability to carry a heavy payload, and the option to handle mild oft-road conditions.

Coupled with the company 's own product requirements of safety, fuel

efficiency, low emissions, and high volume product ion economics, Hypercar has succeeded in coming up with a product design, systems innovations and manufactur ing processes which have truly brought the car into the 21st

century. Its technology could be ready as early as 2005 for integration into

product ion models.

The clean sheet approach How have they done it? David Taggart, senior vice president of product development , was tasked with meeting this

strict set of product requirements. Formerly of Lockheed Martin's aerospace engineering Skunk Works, where

he worked on the design and product ion of a variety of aircraft and challenging structural applications, Taggart brought his unique interpreta-

t ion of the Skunk Works development process with h im to Hypercar. He kept a

small expert team of development engi- neers in an int imate working environ-

men t where he encouraged a discipline of constant dialogue and rigorous decision making as a means of achieving systems breakthroughs without com- promising the product requirements.

The clean sheet approach they applied allowed them to arrive at inno- vative approaches to meeting the prod-

uct requirements, while radically simplifying the design and processes to manage production costs. This has resulted in a platform design and production solution that meets the product requirements, and can be affordably produced at attractive volumes. Yet the design they have engineered is not

restricted to SUVs. The basic design approach, and manufacturing goals, and

mentality of their ' foundation platform' can be applied to any car, be it sportier, larger, smaller, more luxurious, or less so.

Although he was originally schooled as an undergraduate in metallurgical

engineering, Taggart was, nevertheless,

inspired by the design flexibility and outstanding properties of composites. He

then went on to a graduate degree and a professional career in advanced materials, structural design, and programme management prior to coming to Hypercar. There was, therefore, no doubt

for h im that the resulting design needed to be composites intensive, including, of course, the compressed hydrogen tanks.

Taggart then applied the aerospace

design mentality, and brought aerospace manufacturing processes into the equa-

tion to broaden the team's design free- dom and deliver the required repeatabili- ty and performance.

"Air vehicle engineering typically has to deal with intense loads and system complexity. That is not the case here,"

says Taggart." The materials for an auto-

mobile do not require aerospace spec, so

manufacturing processes can be radically simplified, and production costs drop accordingly. Cost was the primary driver

in our design process."

Safety first Taggart and his team have brought breakthrough structural integrity and

safety to their foundation platform by

creating a passenger safety cell made of carbon fibre reinforced plastic (CFRP).

This passenger safety cell forms the main structure of the vehicle including suspension and subframe interfaces, and houses the hydrogen tanks in order to

provide max imum protection and greater safety for the tanks.

Key to the affordability of the inte- grated design and production solution of the vehicle is a proprietary processing step which has the job of preparing the

equivalent of a tailored blank for sub- sequent forming into a final component . This innovation uses existing technolo-

gy, but in a very unique way. The process allows production of 50 000 automotive

safety cells per year in a combination of no more than three vehicle variants, and uses aligned reinforcement to ensure a dramatic weight reduction. The process

is highly repeatable, tailorable, moni- torable and controllable, and allows the

use of either thermosets or thermo- plastics, and either modified stamping or

resin infusion processes in the final processing step to complete the overall

production process. The safety cell has been analyzed

using automotive industry standard

tools and shown to withstand a 56 km/hr (35 mph) head on collision

with a stationary object and still remain undamaged. This far exceeds regular

safety standards, but the team built this level of safety into the design, not only for structural reasons, but also for the benefit of repair and reuse. In factoring durability and re-use into the vehicle, the design compensates for the cost of repairing CFRP structures by forcing energy absorption to occur in the front

S e p t e m b e r 2001 R£11W~V~Dplaslics 5 5


of the vehicle. Energy distribution then takes place in the safety cell, thereby allowing the vehicle to withstand greater impacts with less damage.

Front and rear of the passenger safety cell are tailored crush zones. These are designed to absorb increasing amounts of impact energy prior to damaging the passenger safety cell at higher speeds.

The bumper is made of CFRP designed to withstand impacts up to

24 km/hr (15 mph). The next zone comprises a tubular

aluminium subframe, and numerous suspension and system components. Aluminium was chosen because of its

ability to easily manage a variety of structural hard points and geometric

complexity at low cost, while providing a low risk and repeatable energy absorp-

tion solution. Finally, covering the entire passenger

safety cell, and front and rear crush zones, is a thermoplastic and reusable skin to enable tailored vehicle style, in- mould colour, and dent resistance. Combined with the smooth underbelly of the safety cell, this combination affords a reduction in drag coefficient and gain in fuel efficiency. The Revolution has a drag coefficient of 0.26, making it more aerodynamic than most

sedans, which is outstanding for an SUV with 1.9 m 3 of cargo space. Working

within TWR's engineering facilities in the UK, the Formula One specialist engineering consultancy, the Revolution's

stylists have made the vehicle sleeker than any other crossover SUV on the market or even in the showroom. Yet on the outside the vehicle appears no bigger

than a BMW X5 or a Lexus RX300. "The key to unlocking the weight and

cost reduction benefits of advanced com-

posites is in the simplicity of the design and overall integration of that design with an interdependent process solution," says Taggart. "By working very hard to tailor the structural design, and by developing the production processes ideally suited to producing the parts, we have greatly simplified the overall tool-

ing, production and assembly approach. The design is now so simple that the components of the safety cell fit together with min imum effort, much like a Revell toy model kit."

Durability has been built into the design from the beginning. This is another of the advantages of composites, which do not rust, or degrade easily, and in this case, do not go through an expensive and environmen- tally detrimental spray paint job. Most

of the components are designed to be reused in other product forms, and the vehicle's digital 'nervous system', incorporating the latest software and electronics, can be remotely upgraded diagnosed and repaired, and to a large

degree, choreographs the dismantling of the vehicle's components at the end of its useful life.

Economics The design has not been without its hur- dles though. Yet with their 'no compromise' approach, the team has either turned the problem into an overall product advantage, such as making the structure so durable that it needs little repair, or has simplified the problem so that it

does not present itself as one. It would, for example, seem advantageous to make the most of composites' properties to embed electronics into the material

itself, and thus simplify the design fur- ther. But, once again, repairing embed- ded wires, if needed, would be difficult, and it would add to the complexity and production cost of the structure, so the

team has taken the decision to leave most of the electronics outside of the structure.

One of the unique outcomes of

Hypercar's design approach is that it has brought the main structural frame inside the vehicle, instead of making it a part of

the outer surface. Taggart maintains that separating the

structure from the skin was desirable for a number of reasons, one being that it is possible to change the outer skin of the vehicle as styles change over the years. More importantly, the structural

components could be tailored to do the job required of the structure, in as low cost a manner as possible. Coupled, in addition, with all the other upgrade- able features of the vehicle, the design allows an individual to considerably upgrade a vehicle without having to buy a new car.

Hypercar's target production volume is 50 000 units per year, which repre- sents an important threshold level for the original equipment manufacturers

56 P.EIl~lCEDplastics September 2001


(OEMs). The company forecasts that its

average production spec will be higher in

materials costs, but considerably lower in assembly and production overhead costs. Its clean sheet approach and whole system vehicle understanding has emphasized the need to eliminate ineffi- ciencies and minimize waste throughout the entire manufacturing process. The design as a result is also extremely efficient on accessory loads and perform-

ance, especially for a car that can get 0-96 km/hr (60 mph) in 8.3 seconds, with four wheel drive capability and

variable attitude control and ground clearance. It would be difficult to com- pare these economics to other composite

vehicles as they tend to deal only in smaller volumes, and avoid high manufacturing costs by making composites only a part of the structural solution and

less a part of the chassis system.

"Making something simple is a

complex process," says Taggart, "whereas it is very simple to make something

complex."

Low retooling costs would allow for highly tailorable production runs.

With such a simple vehicle design and correspondingly affordable manu-

facturing costs, it would, therefore, not be a big investment for Hypercar to retool for a new design. Low retooling costs would allow for highly tailorable

product ion runs, something which only Toyota is really striving to do with steel cars, and which to date has eluded

the conventional car manufacturer. Hyper-car forecasts that tailorability and

upgradeability is the key to niche mar-

kets and will give the manufacturer

which takes up its design concepts and systems innovations the competitive edge over the manufacture of conventional steel vehicles.

Hypercar's product development approach and technical innovations are

a game changer for sure, and it will be inspiring for composite material produc-

ers and manufacturers around the world to track what might be the first 'volume

production carbon reinforced solution' inroad into the automotive world. •

Hypercar Ira:, I I 0 Midland Avenue, Suite

202, Basalt, C O 81621, USA; tel: +1-

970-927-4556; fax: +1-970-927-4593;

website: w w w . ~ c o m .

Cus tom Prof i les - S ta nda rd Prof i les - S t ruc tura l UP TO 1,5 mt. WIDE Available in a wide variety o f shapes, colours, f ibers (glass and carbo resins (polyester, vinylester, acrylic, phenolic, epoxy)

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September 2001 REIl~:OltGFDpla~tics 57

Hyper

Technology

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