Tech Briefs
Scapa gets taped
 Adhesive tape specialist, Scapa, has developed a new method for securing folded airbags. |
Adhesives specialist Scapa has developed a new method for securing folded airbags. According to the company, despite initial skepticism, trials in conjunction with a leading airbag manufacturer proved that high-performance tape could meet required criteria. The application is for side-impact bags that are positioned in the cantrail between the A- and C-pillars.
Normally, airbags are secured via molded or fabric covers, but adhesives offer a lower-cost alternative. To ensure controlled deployment, it was important that a tape be developed that would shear at an optimum load. Performance had to span a temperature range of -35 to +85°C (-31 to +185°F). The tape also needed to be clearly identifiable to avoid accidental removal by engineers during routine servicing. Scapa has developed an acetate cloth tape for the task—code 1301—printed with the word "airbag" for clear identification. It is now used in cars produced by several European manufacturers.
- Stuart Birch
GM production speed
   The extensive use of math-based tools enabled GM engineers to develop the 2002 Hummer H2 from concept to production in 16 months. |
The average product-development time frame from 1998 to 2000 for General Motors' vehicles—including the Saturn L-Series, Oldsmobile Aurora, Pontiac Aztek, Chevrolet Avalanche 1500, and Buick Rendezvous—was 33 months. GM is now completing product development cycles for such vehicles as the Chevrolet Avalanche 2500, Saturn VUE, Escalade EXT, Pontiac Vibe, and Hummer H2 in time spans of 16 to 27 months.
"We've simplified how we do product development quite a bit," said Tom Davis, GM Group Vice President for North America Product Development, during a media briefing at the Pontiac Centerpoint Campus. In 1995, GM's North American product-development landscape consisted of small-car engineering, mid-luxury vehicle engineering, truck engineering, design, and vehicle line executives. In 1999, product development encompassed car engineering, truck engineering, design, and vehicle line executives. But in 2001, product development shifted to combined car/truck engineering, design, and vehicle line executives.
CAD/CAM/CAE tools also are reshaping the product-development landscape. Consider that from 1998 to 2001, there was a seven-fold increase in testing requirements. Since the price to produce a full vehicle physical prototype is about $1 million, technology tools have helped control the cost spiral. "The cost of engineering—if we hadn't done what we've done—would have exploded," said Davis, underscoring the move toward using math-based technology for validation purposes.
Time improvements also have transpired from the use of metal-forming simulations. "GM's proprietary math tools for metal forming provide the accuracy to do tool dies quicker," said Edward Koerner, Executive Director of Vehicle Systems. Because GM produces a substantial number of dies and metal parts (including fenders, hoods, quarter panels, and trunk lids) in-house, math-based technology is crucial. "Metal forming is viewed as one of our core competencies," said Koerner.
The 2002 Hummer H2, a 4x4 vehicle based on a modified GMT800/full-size pickup truck platform, unfolded within a 16-month product-development time frame. (Development time in this case is defined as after concept to start-of-production.) As the first GM vehicle—interior and exterior—designed and validated extensively with math-based tools, the H2 also saved development time via parts sharing. For example, the brake rotors and calipers used on the H2 came from the current 3/4-ton full-size pickup trucks. "When possible, you can save several months to a year of development time by using existing components vs. developing all-new components that are specific to the application," said Koerner.
GM's present product-development practices emphasize a focused team, job accountability, around-the-globe resource utilization (sharpened via the 15 engineering center locations for vehicle design, integration, development, and validation), as well as math-based technology.
- Kami Buchholz
