Saving the Lives of Drivers

In the wake of the death of beloved NASCAR hero Dale Earnhardt and other drivers who met their fates at "the wall," scientists at the University of Dayton Research Institute are working in overdrive to help create two different energy-absorbing devices designed to save drivers' lives.

During his days as a race-car crew chief and engineer, Mike Merkel was losing too many of his friends to collisions with race track walls, he said. Now president of Merkel Composites in Eureka, Calif., Merkel has commissioned UDRI research engineer Kevin Poormon and his impact physics group team to test and evaluate an energy-absorbing racetrack wall "cushion."

In a separate cooperative venture, UDRI research engineers Bill Braisted, Bob Brockman and other members of the structures group are working with Paul Lew of Lew Composites in Las Vegas to develop the Humpy Bumper -- also a lightweight, shock-absorbing device to be marketed to the stock car industry. Both the structures and impact physics groups are part of UDRI's aerospace mechanics division.

The primary goal in both projects is identical -- reduce the g-load (shock) experienced by drivers when their cars collide with race-track walls. Both projects were inspired by driver fatalities incurred during such collisions.

While Earnhardt was not the first to die in an automobile race, his death and those of Adam Petty and Kenny Irwin in less than two years have pushed safety issues to the forefront in the stock-car racing industry.

In fact, Poormon and Merkel have been working on the wall barrier project since January -- one month prior to Earnhardt's death.

"We actually came up with the idea about five years ago," Merkel said. "The goal was to develop a lightweight composite to put on concrete walls that would be hard yet still energy absorbing. Most materials that absorb energy are not hard, but we wanted something that would stand up to the normal wear and tear of a racetrack and take a brush from a vehicle without needing repair, yet that would yield at a higher impact." The material also needed to be cost effective and easily manufactured and replaced, he said.

Using foam and carbon fiber materials, Merkel created a lightweight compound he believes will meet his criteria when applied in an eight- to 12-inch layer. According to design, the carbon fiber surface of the barrier will crush at first impact, distributing the impact load over the underlying foam that will also collapse.

The next step in Merkel's plan was to locate a site with the resources -- knowledgeable staff and equipment -- to properly analyze, test and suggest improvements to his design.

"I did my research and decided that the University of Dayton was better able to handle this project than any other place we found," he said.

Using the institute's compressed-gas launching gun -- normally used to test the strength of airplane windshield and canopy materials -- Poormon set up projectile tests that simulated high-speed vehicle impact. When launched, the projectiles' on-board measuring devices recorded deceleration and g-forces at impact.

"Preliminary results indicate the barrier does substantially reduce g-load," Poormon said.

"I couldn't be happier with the results Kevin has come up with for us," added Merkel, who is hoping to gain NASCAR approval and begin production in time for the 2002 racing season. He has also received support from CART (Championship Auto Racing Teams), the open-wheel racing industry.

Meanwhile, Braisted and Brockman have been working evenings and weekends to complete the Humpy Bumper project, commissioned by Lew Composites in late May with a request that eight weeks’ worth of analysis be completed in two.

The project evolved from happenstance, when A.J. "Humpy" Wheeler -- president and owner of Lowes Motor Speedway as well as a bicyclist -- sought out and asked Paul Lew for a tour of his bicycle-wheel manufacturing plant during a visit to the Las Vegas Motor Speedway, where Lew's plant is located. As a maker of bicycle wheels, Lew has developed expertise in manufacturing materials with high strength-to-weight ratios.

During their plant tour, Wheeler, recognized as a champion for safety improvements in the NASCAR circuit, asked Lew if he might be able to design a lightweight, energy-absorbing bumper for stock cars, which currently aren't equipped with bumpers. Lew Composites quickly produced an initial design for the bumper, then enlisted the help of UDRI to evaluate and suggest improvements to the design to maximize safety benefits.

Braisted said all tests and analyses have been computer-generated thus far. By plugging all necessary data into the computer, he and Brockman have been able to create virtual crashes and record the performance of the bumper during collisions.

"The bumper is designed to reduce g-load on the driver by absorbing impact over a longer period of time," Braisted said. "Using carbon fibers imbedded at varying angles within resin materials, the bumper will crimp and buckle over an elongated period of time, helping to absorb and disperse some of the energy of impact before it gets to the driver.

"Initial tests have shown that the bumper will indeed substantially reduce g-load, which is great news," Braisted added. "We'd much rather see a bumper broken and mangled than a driver."

With initial tests completed, the bumper is on its way to General Motors in Detroit, which is donating the use of its crash test facilities for live model testing. The bumper will then be returned to UDRI for final analysis and design improvement suggestions.

"Theoretically, we could produce enough bumpers within 30 days to outfit all of the Winston Cup teams in time for this racing season," said Lew, who is confident his device will be approved by NASCAR.

During a recent visit to campus, Lew said he was referred to UDRI by an acquaintance at General Electric Co. who has also worked with the institute. "I was told, and firmly believe now, that no one else in the world can match the crash-simulation capabilities of UDRI. This is a state-of-the-art facility."

June 7, 2001