Engineering News 7534Engineering News 7534

Engineers keep things green

Lasers and fiberoptic technology help engineers identify and decontaminate hazardous waste

Waltham, MA--Hazardous waste. No one likes it. No one wants it. So engineers are doing something about it. Armed with lasers and fiberoptic technology, they develop safer, cleaner, handling and treatment processes.

Take the Hazardous Waste Identification System for example. This infrared fiber optic probe, developed by Foster-Miller and commercialized by Sensiv (Waltham, MA), identifies liquid hazardous waste on site, in real time. Analysis requires no sampling, no shipping, no lag time.

Engineers originally developed the probe for the U.S. Air Force for easy analysis of liquid refuse such as leftover paint or floor washings. Presently, spent liquids are sent to a central area on base, where the environmental engineer samples every drum and sends these off to a lab for analysis. With the Sensiv probe, the engineer can wheel the device from container to container and analyze its contents immediately, minimizing direct handling of the material as well as saving time and money.

When a sample goes to the lab, the analyst places the liquid inside an infrared spectrometer. Sensiv brings the IR spectrometer to the sample via fiber optics, says Mark Druy, materials scientist and vice president of Sensiv. An infrared energy source, in the spectrometer, sends light through a fiber optic cable and probe to the liquid waste. As the light makes contact, the sample absorbs energy. The amount absorbed depends on the components in the sample--different molecular bonds absorb energy of different wavelengths. The remaining energy travels back through the fiber optic cable to a detector in the spectrometer, where a computer program develops a fingerprint or spectrum of the liquid. Operators compare this print to an on-line library of standards.

Sending energy back and forth created a challenge for Druy and associates. They struggled to understand how IR energy is transmitted through optical materials so they could design a sensor region that allowed IR light to interact with the waste and still return light to spectrometer. "Over a certain length of fiber, you only want to transmit energy," says Druy. "In other parts, you want the energy to leak out so it can interact with the sample. Then, it must transmit back to detector without leaking out again."

Sensiv used a computer to model the propagation of IR energy through a commercially available fiber. From this information, engineers developed the mechanical steps required to generate a sensor.

To create a sensing region, engineers bent the optical fiber in the shape of a "U" and potted it in an epoxy. "Then we polish through the cladding of the fiber into the core over a defined area," says Druy. Sensiv received a patent for this type of sensor in 1996.

A second, though slightly easier challenge: mechanically package the device to withstand a rugged environment. Sensiv used chalcogenide glass from Amorphous Materials, Inc. (Garland, TX) for both fiber and probe, housed in stainless steel.

The military uses the hazardous waste identification system for characterizing liquid waste that primarily contains organic and some water-based inorganics. In the commercial sector, spill response teams could benefit from such instant feedback, says Druy.

Other IR probes are on the market today. "Ours is unique because of its transmitting efficiency," says Druy. The device can transmit about 5% of the energy available in the sample compartment of the spectrometer. Competing products only transmit 1% or 2%.

The U.S. Department of Energy (DOE) gave Martin Edelson, a scientist at the NASA Ames Laboratory (Moffet Field, CA), a mission: remove radioactive-contaminated metal from metal surfaces.

His solution: laser ablation. "The laser is a new industrial tool," he says. "It's as useful as a lathe or a mill. And what is particularly attractive, is that it's wonderfully versatile."

In 1989, the DOE looked into the large inventories of metals at its sites, whose surfaces were contaminated with radioactive isotopes. Without effective cleaning, the DOE would be forced to bury millions of pounds of contaminated and potentially valuable material.

The nuclear industry had a similar problem. The coolant systems of commercial nuclear reactors use very large, heavy-walled pipes. After long service, they become radioactive. Some contaminants actually exchange places with non-radioactive isotopes of the same element and can migrate into the pipe about ~50 to 100 microns. Because the impurity sits relatively close to the surface, much of the metal could be recovered if properly cleaned.

Edelson suggested lasers--which can precisely deposit energy at large distances--to ablate material from surfaces. The researcher faced a unique set of engineering challenges: What was the right laser for the job? How to prevent material from redepositing on the surface once it had been removed? Could this method operate quickly enough to compete with other decontamination techniques?

Lasers are classified by several parameters, says Edelson, such as wavelength of light emitted, repetition rate, energy, and pulse length. "We needed a relatively fast pulse laser, with pulse lengths in the nanosecond range, a high repetition rate, and a pulse power of many millijoules."

After Edelson proved the feasibility of laser ablation, a collaborative project with Westinghouse Idaho Nuclear Company (WINCO) and AMES took the idea one step further. WINCO needed to decontaminate highly radioactive surfaces in controlled environments such as gloveboxes or hot cells.

This new, recently patented, technology relies upon optical fibers for laser transmission to surfaces that require cleaning. "We found that using a neodymium: yttrium aluminum garnet (Nd:YAG) laser with an acousto-optic Q-switch (a mechanism for producing fast laser pulses reproducibly at high repetition rate), we were able to efficiently transmit powerful laser pulses to surfaces and clean them better than ever before."

Because the laser light is ported through optical fiber, the laser and laser operator can be hundreds of feet away from the objects being cleaned--a significant advantage when dealing with radioactive materials. Testing indicated that the fibers were rugged (one fiber lasted for over one year) and could withstand radiation well.

Laser cleaning offers an important advantage over mechanical cleaning. When the operator focuses a laser onto a surface, the intense energy creates a small plasma that can be used for process monitoring. Materials removed from the surface become electronically excited in the plasma and, as they relax to their ground states, they emit photons of light that are characteristic of their chemical identity.

If the metal is contaminated with cesium, a common reactor contaminate for example, an operator will see an intense cesium wavelength emitted at the beginning of the process. As laser ablation continues, the cesium signal intensity diminishes and, eventually, becomes undetectable. Then the operator knows when to stop.

The biggest advantage of the laser ablation method, says Edelson, is that it is clean. When the right laser is used, the particles formed by ablating materials from a surface are small and easily collected using a vacuum-blower with an in-line high efficiency particulate air filter. "There is essentially no secondary waste formed during this cleaning process," says Edelson.

Other cleaning technologies, such as waterjets and abrasive blasting create significant secondary wastes that are often hazardous. These methods also expose workers to potentially dangerous situations.

The laser decontamination technique developed by Edelson, Homing Pang (Ames), and Russ Ferguson (Lockheed Martin Idaho Company - the successor to WINCO) was licensed to ZawTech (Zero Added Waste Technology) Co. in 1997.

For more information about laser ablation contact Jerry Decker, ZawTech International Inc., (770) 495-3929.

What this means to you

Aluminum foam 'sandwiches' auto panels

Osnabruck, Germany--Sandwich panels and aluminum foam are not new, having been around for more than 40 years. However, conventional sandwich panels typically exhibit low durability, high production costs, and can't be formed into complex shapes. A new process developed by Karmann GmbH in conjunction with the Fraunhofer Institute (Bremen, Germany), overcomes these problems.

The process involves the use of powder metal technology to produce the aluminum foam. Complex sandwich panel parts result--using only a forming tool and no added adhesives between the outer layers and the core foam.

The part's outer layers are stamped into the desired shape in the same manner as a typical aluminum pressed part. Then, through an endothermic reaction, the aluminum powder melts. The expanding gases trapped in the molten mass create a porous foam. The foam expands between the two aluminum sheets to the final height of the sandwich. Producing such parts costs less than using the conventional methods, claim Karmann's Hans-Wolfgang Seeliger and Winfried Bunsmann.

Based on crash tests, the researchers say the aluminum foam has good potential to be used as an energy absorbing element, particularly in automotive applications. Due to its ease of forming, they feel it is especially suited for frontal crash-absorbing components. Such sandwich panels, they believe, have an advantage due to their higher stiffness-to-weight ratio when compared to conventional steel or aluminum sheet parts.

Mass production of the parts is anticipated by the year 2000.

Wescon exhibitors look to future

Anaheim, CA--While attendance at this year's Wescon/IC Expo '98 electronics components trade show may have dipped slightly from last year, data on the exhibitors showing their wares make interesting fodder for future expectations. Those coming to the show dropped to 31,011 from 32,064 in 1997 when the exhibit was held in split Silicon Valley venues in San Jose and Santa Clara, CA. Two years ago, 37,470 came to the exhibit, again in Anaheim. The numbers quoted include preregistered guests and walk-ins.

Tone on the floor was somewhat subdued, highlighted by the lack of presence by Hewlett-Packard. But while some exhibitors commented on noticeably reduced traffic, others reported brisk business and lead generation. The Asian financial crisis and economic slow down was evidenced by fewer attendees from the east Asia Pacific Rim, 297 compared to 488 in 1997. However, confidence in the future, and aggressiveness in pursuing new business, was demonstrated by the soaring number of Asian concerns exhibiting at Wescon, well over double the number present last year--74 (of 114 international exhibitors) versus 32 in 1997. These break down to include 40 from Taiwan; 7 from Hong Kong; and 21 from Korea; two each from Singapore and Japan; and one apiece from Malaysia and India. The low tally of Japanese companies may indicate the poor economic climate there may take longer to improve than in the other countries.

Rick DeMeis,
Associate Editor

Hearing tests made fast, easy

Elk Grove Village, IL--Statistics show that up to 24,000 children born each year suffer from some degree of hearing loss. However, most young children prove extremely difficult to test using traditional methods. That's no longer the case.

Instead, such tests can be conducted in six frequencies and in three seconds. A new screening instrument called Ero-Scan^TM made by Etymotic Research makes it possible. The self-contained, handheld device can test infants, children, and adults.

Materials played an important role in bringing the device quickly to market. In fact, short lead times and precise color matching capabilities invited molder GBE, LLC (Gurnee, IL) to RTP Co. (Winona, MN) where color specialists critically matched two different precolored compounds to an auxiliary printer that outputs the test results.

"We did our homework and decided on RTP," says Mike Thompson, manager experimental molding at GBE. "The color looked good, the material molded well, and it was delivered promptly."

The new device incorporates several components made of the compounds. The instrument casing, for example, consists of a precolored PC/ABS with an unnotched impact strength at 1/8 inch of 35.0 ft lbs/inch (1869 J/M), and a tensile strength of 8,500 psi (59 MPa). The probe housing is molded from precolored Santoprene(R) with a Shore A hardness of 80. Both compounds are FDA compliant.

"We wanted the benefits and flexibility of ABS, combined with the strength of polycarbonates," notes Steve Iseberg, product manager with Etymotic Research. "These are handheld instruments that need to survive impact and accidental dropping. The parts are so sturdy that I can bend and flex them, and they maintain their shape without cracking."

Placed gently in the ear, the Ero-Scan quickly tests hearing using the half-dozen frequencies available on the device, then it automatically saves the data to memory. Following the test, the instrument is placed in the cradle of a high-speed printer, which prints out the results in three seconds.

Chrysler goes paperless

Detroit, MI--Ah, the paperless design--to develop a product from concept to prototype entirely on the computer. Is it possible? Chrysler says it is. In fact, the company's 1998 Dodge Intrepid was the first car to be 100% digitally designed, says Greg Avesian, manager of solutions marketing for the technical computer center for Chrysler.

When the car made its TV debut in a 1998 Superbowl commercial, its claim to virtual development caught people's attention. A three-star general from the Pentagon, as well as the vice president of Johnson & Johnson's diaper division, paid a visit to the auto manufacturer asking, "How did you do it? How can this process be applied to our business?"

Chrysler is proud to talk. Working closely with Dassault and IBM, Chrysler designed the car with CATIA(R). When the company decided to test the paperless waters for its new sedan design, it went cold turkey on the early phases of physical mockups.

This was the only way to get a team of engineers to embrace such a new concept, Avesian says. "People will naturally gravitate to what they're comfortable with. We wanted to be confident that every single component would be designed in CATIA--this extended to suppliers as well."

In the early 90s, Chrysler standardized on one CAD platform for the company and all their suppliers. Avesian says, "Before, our focus was to design on computer, and send out information to suppliers who would build a prototype part. Weeks would go by before parts show up. While waiting for the parts, the design continued to evolve. By the time the parts arrived, they were out of date. By doing this in an electronic world, we get instantaneous updates. The whole team is notified, engineers, suppliers, as design changes take place."

Generating code for design

Andover, MA--More than just CAD and PDM companies are getting into the virtual design act. Chrysler recently implemented I-Logix' Statemate MAGNUM--a modeling, simulation, and automatic code generation software tool, to design and specify body electronics on its Jeep(R) platform.

Bob George, executive engineer for Chrysler's Jeep platform, says, "Statement MAGNUM has helped us to advance our design and specification process. Just as TV viewers have seen in our recent advertising campaigns, we are now building and testing vehicles in a virtual prototyping environment." Engineers use Statemate to design and specify controller functionality for overhead console, audio, and remote keyless entry systems. The software tools automate design chores, such as requirements traceability, debugging, and documentation.

Embedded systems developers use Statement to graphically model, simulate, analyze, and verify the functionality and behavior of complex systems. The C or Ada source code can be automatically generated from a verified Statemate model.

Web address: www.ilogix.com

Analysis improves cardiac treatment

Birmingham, AL--Future implantable heart-control devices use long line electrodes rather than the more common point electrodes found in today's devices to more effectively detect when a heart is out of rhythm.

That's one of the possible results from research underway at the Cardiac Rhythm Management Laboratory at the University of Alabama. Researchers are studying ways to improve current automatic implantable cardioverter/defibrillator (AICD) devices, and trying to learn more about the fiber structure of the heart itself.

Among the tools in the research: finite element analysis software from ALGOR.

ALGOR's electrostatic FEA software is helping researchers study the distribution of an electric current as it flows through the heart. They hope to develop techniques that would create a more uniform change in membrane voltage to more efficiently halt ventricularfibrillation.

The point electrodes emit electric current that spreads radially from the source. However, the fibers of the heart can create resistance to the current, causing an uneven spread of current and a non-uniform distribution of transmembrane voltage. The shape of a point electrode prevents it from orienting in the direction of the heart's fibers to reduce resistance. Researchers thought they could position longer line electrodes either parallel or perpendicular to heart fibers to better transfer current, but first they needed to determine the density or distribution of the electric current a line electrode emits.

Researchers used Algor's Superdraw III to model a 100- x 100-cm sheet, which represented a conductive area of the heart. Then, they applied a resistivity value based on a thickness of one cm to simulate a uniform resistance over heart fibers. A 3.6- x 3.6-cm central region contained a 1-cm-long electrode in the center. They used voltage boundary elements at the points on the sheet in contact with the electrode, smaller 2D planar elements around the electrode, and larger elements for outlying areas. They specified that a voltage of 100V be applied at the electrode, and that voltage be zero at the perimeter of the sheet.

The finite element model showed that current through the element faces at the ends of the electrodes was 151% larger than the current near the electrode center. Researchers also used FEA to determine that the length of the line electrode does not affect the current distribution.

Next step was lab tests in which researchers applied line electrodes in varying positions and orientations on 13 rabbit hearts. Results correlated with the results of the electrostatic analysis.

Researchers say they can apply knowledge from the finite element analysis to design of future AICDs to regionally block areas of the heart from becoming out of synch and prone to fibrillation. Additionally, they say, line electrodes could play an important role in developing new, less invasive therapies for heart disease. Among the possibilities: inserting line electrodes in the heart through cardiac veins for therapeutic treatment. That could increase the efficiency with which electric current is applied to the heart by distributing current from several electrodes. It's also less traumatic than some previous methods that required surgical procedures to open the chest.

Researchers were also able to determine the distribution of the change in transmembrane voltage from a line electrode using electrostatic analysis. In the future, they could use FEA to study electrodes of other shapes to determine the potential of different types of electrode configuration.

Engineering salaries on the rise

Washington, DC--Engineering salaries continue to move upward, even with the rate of inflation factored in. That's the latest finding from the 1998 survey of salaries conducted by the Engineering Workforce Commission (EWC) of the American Assn. of Engineering Societies (AAES).

The survey found that the 1998 compensation for mid-career engineers with 12 to 14 years in the workforce increased by 3.1% from 1997. Meanwhile, the U.S. Bureau of Labor Statistics reported that from February 1997 to February 1998 the rate of inflation was 1.5%. Moreover, the American Compensation Assn. noted that the national average base salary for all U.S. industries went up only 2.9% in 1998. Meshing all these statistics, engineers' salaries stayed ahead of inflation and the national average of other industries.

The 32^nd edition of the EWC survey includes information about 170 major corporations. The findings represent more than 73,000 engineers in 18 experience brackets.

Based on survey results, entry-level and early-career engineers experienced a larger increase in salaries than did mid-career engineers. For instance, in 1998 the median salary for all engineers five years out of their undergraduate program has reached $49,150, compared to $42,000 last year, an increase of 8.5%.

Petroleum engineers with a BS remain the highest paid at the entry level with a median starting salary of $51,050.

Using survey data, the EWC now offers engineers a one-page salary review entitled "Personal Salary Profile." The $25 personalized report matches the engineer's salary with those of his or her counterparts based on the engineer's industry, geographic region, level of education, years of experience, and supervisory status. Contact EWC Manager Amy Goldman at (888) 400-AAES x209.

Plastics push automotive design frontiers

Newton, MA--In spite of the growing use of plastics for automotive applications, the plastics industry isn't taking anything for granted. That's why the American Plastics Council (APC) opened an Automotive Center last September in Troy, MI. The center's goal: "to provide automotive OEMs, suppliers, and systems integrators with a focal point for automotive plastics applications and concepts."

The 6,200-sq-ft facility's flexible, two-suite design allows one suite to serve as an application showcase, classroom, theater, and conference room. The other suite will feature an advanced computer and video center where engineers can browse the latest reports, publications, and videos on automotive plastics.

"We see the center as a place of continuing education for engineers about the use of plastics and plastic technology," says Bruce Cundiff, the center's director. He foresees APC and the Society of Plastics Engineers conducting many workshops and seminars at the facility. "We also hope to reach those engineers who are designing primarily in metals, and, if we do our job right, try to make them think of plastics first."

Plastics producers aren't about to let APC do the entire selling job for them, however. In fact, most of the major resin suppliers have technical and research centers in the Detroit area to push their products and offer design support to automakers and their component suppliers.

"The demands on material suppliers today are a lot different than they were 10 to 15 years ago," reports William Windschief, senior marketing manager for Montell Polyolefins' North American Automotive Group, also located in Troy.

It's an industry-wide race for the materials suppliers who have plowed major investments into their own design, manufacturing engineering staffs, and technical labs. They want to offer the material and the technology for a virtual turnkey product. Many even have a team with design, manufacturing, and product engineering expertise at customer sites.

"I think we are a pioneer of co-located, full-service teams that assist with engineering, design, and prototype building," notes Owen Maher, Tier One team director for GE Plastics.

Late this year, GE Plastics will have even more to offer its automotive customers with the opening of a new technology center at its Southfield, MI automotive hub. The project includes a "predictive engineering" lab that will enable engineers to envision different materials on car models.

"We have a new computer suite where our industrial designers can draw a concept, put an engineering mesh around it, and electronically transfer it in milliseconds to our engineering group, which will analyze it, optimize the geometry, and get it back to the design team within hours," says Tom Clinton, the center's director of technical information.

The new facility also will provide instant access for engineers to GE Plastics' huge Polymer Processing Development Center in Pittsfield, MA. Via video conferencing on 9-ft screens, engineers can take a "virtual" tour of the various labs located in Pittsfield. They will be able to see one of their component designs actually being molded, and can talk directly with team members responsible for working on the project.

To top it all off, a former information systems area at the Southfield automotive center is being gutted to create a tear-down garage where engineers can dissect car parts from a complete vehicle and analyze a component's material makeup on CAE stations.

"The OEMs are buying part performance or modular system performance," adds Alan Wilson, automotive interior/exterior group sales manager for Ticona (Auburn Hills, MI), a member of the Hoechst Group. "In many cases, the Tier One company has the authority to select the material, but it often must select from a list approved by the OEM." Plastics suppliers hope to have their names on that list through the design services they offer throughout the automotive arena.

Gary Chamberlain,
Senior Editor

A sedan for the long haul, the Saab 9-5

Stockholm--We only had our new Saab 9-5 for a week when it was time to put it to a real test--a two-week family vacation through Europe. From Stockholm to Lake Garda in northern Italy, the car faced many different road and driving conditions: high-speed cruising on the famous German Autobahn where there is no speed limit in many sections; advanced maneuvering on the twisty roads of the Alps and Dolomites; and the extreme heat of the Italian summer.

A 2.3l four-cylinder, Ecopower light-pressure turbo, delivering 170 hp with four-speed automatic transmission, powers our 9-5. Leather seats and the wood-panel dashboard make for a nice and classy interior. And our family of four adults and one child can sit easily in comfort. The well-placed instruments and the easy-to-use trip computer are handy on the long journey. The only complaint: for tall drivers (I'm 6' 3''), the seat feels a little bit too short to support the thighs.

Before starting out early one morning this past July, we are a bit worried about the big pile of luggage we plan to load into the car. But, typical of Saab designs, we are pleasantly surprised when the 15.9-ft³ trunk swallows everything, without having to store anything in the back seat.

After driving to Goteborg and a night on the ferry to Germany, we are anxious to get on the road. Here Autobahn driving requires you to be very alert--all of a sudden a raging BMW or Mercedes is on your back doing 230 kph (140 mph)! Because the 9-5 is so comfortable and silent, there are none of the typical cues impeding driving at these high speeds--you get speed blind and before you know it you're going 210 kph (130 mph)! We decide to drive a little bit slower, around 160 to 170 kph (100 to 105 mph).

With five passengers and luggage, the 9-5 is heavily loaded. But acceleration, while not crisp, is good enough to make safe takeovers thanks to good low-end torque and the "sport" downshift-mode button on the automatic transmission lever. With radio and CD player controls on the steering wheel, my hands rarely have to leave the wheel, aiding road control. The 9-5 turns out to be a great car for driving long highway distances thanks mostly to the comfort and the low level of noise.

Wunderbar. Reaching southern Germany, we spend the night in the wonderful little medieval town of Rothenburg am der Tauber. The following day we tackle the Brenner Pass at the border of Austria and Italy. The Alps are beautiful and have fun roads to drive--twisty and hilly, perfect to wring out turning and braking. And this Saab does not disappoint. With the automatic transmission making the necessary gear changes, the excellent suspension, typified by the new multilink rear axle that individually suspends each wheel with three control arms, makes the 9-5 a real pleasure to handle with a comfortable ride. Another nice touch is the high-pressure windscreen washers, a trio of twin nozzles that instantly floods the glass so the wipers do not drag dirt across a dry surface.

Driving into Italy, the rain lets up and the thermometer climbs to 30C (86F). Unlike in America, most European cars do not include air conditioning--now we are thankful it does. The Saab also has a fun feature--a refrigerated glove box. While taking a while to cool, it then keeps your beverages at a nice temperature--so the heat was no problem for us.

That same day the 9-5 brings us to our destination, Lake Garda. The trip computer outputs gas mileage for the nearly 2,000-km (1,250-mi) road trip as 8.4l/100 km (28 mpg), which in my eyes is rather high and one of the few negative comments about the Saab. It must be kept in mind, however, that the car was heavily laden, and the high speeds on the Autobahn. (I am used to driving a Volkswagen Polo, not available in the U.S., having mpg in the high 30s.)

Overall the 9-5 was excellent for this long-distance trek, and even more so was going home with an additional cargo of fine Italian wines and other souvenirs. I am sure we'll consider using it for many more family vacations in the future.

Mattias Holm,
Contributing Editor, Sweden

Jaguar engine sports nylon manifold

Telford, England--Rack up another first for Jaguar. The latest XK8 sports car features a lightweight, high-performance nylon air-intake manifold with a molded-in fuel rail.

The automaker claims the integrated air-fuel module with two fuel passages into the body of the intake manifold breaks the mold when it comes to under-the-hood components. Siemens Automotive's Powertrain Air Induction Operation makes the nylon manifold/fuel rail using the fusible-core, injection-molding (FCIM) technique. For the AJV8 engine, FCIM won out over vibration welding injection molding in order to meet design requirements of the manifold's complex runner angles.

The manifold, with its molded-in fuel rail, weighs about 8 lb. That's nearly 50% less than a similar design based on pressure-cast aluminum would weigh. Siemens turned to Ultramid(R) A3HG7 black 2056 type 66 nylon supplied by BASF Plastics (Mount Olive, NJ) for the project.

The smooth inner walls of the injection-molded manifold increase air flow. This, combined with the low thermal conductivity of the nylon manifold, helps improve engine performance up to 5% more than that of an aluminum counterpart. And the nylon manifold insulates the air inside from engine heat, allowing high-density air to flow into the engine.

The specially formulated 66 nylon resists hot engine temperatures and attacks from oil, gasoline, and battery vapors. It also produces a manifold that better withstands engine vibration stresses, while reducing engine noise, according to Siemens engineers.

Polymer survives harsh world of disc drives Oklahoma City--A metal plate spins at 7,200 rpm inside a computer's hard disc drive. Less than three virus-widths above that surface resides a rock-hard ceramic block on the end of an aluminum arm. The temperature inside: 500 to 600F. Under these conditions, Seagate Technology engineers searched for a "perfect material" to provide connectors with the proper electrical insulation, dimensional stability, flame retardancy, rigidity, and creep resistance for the drives. They also needed a material that would not out-gas inside the drives. One material met all the requirements--a new grade of Ryton(R), R-4-230NA, a polyphenylene sulfide (PPS) from Phillips Chemical Co. (Bartlesville, OK). Following a 15-month selection process, Seagate engineers chose Ryton PPS for the 2-mm electrical flex connectors in the head disc assembly (HDA) of Seagate's Barracuda product line. They also have the material under consideration for other HDA components, and even refer to the PPS as a "drop-in replacement" for all questionable polymers in the Barracuda 3.5-inch-drive line. During the months-long material search, Seagate engineers found many materials they liked. However, they soon discovered that each had a problem, particularly during secondary processing operations. "Our reflow process broke down some materials, causing out-gassing and HDA contamination," notes Miran Sedlacek, engineering vice president for Seagate's Oklahoma City Operations. As a result, the company now produces and installs complete prototype models of a new material before conducting material acceptance tests. With only a 200 cc internal volume, various hard disc drive parts move at extremely high speeds with extremely tight tolerances. "A drive's recording heads are only about 0.02 microns above the spinning discs," Sedlacek adds. "It's the critical manufacturing dimension in a drive." Ryton PPS' stiffness and creep resistance also make the material ideal for load-bearing applications, such as the actuator latch and stop, Seagate engineers report. The company may combine the two structures into a single part to save manufacturing time and cost. "Even if we don't combine them, we'll save money with Ryton," says Sedlacek. "The current stop is a polymer-overmolded metal piece, while Ryton is strong enough to be a single, unreinforced molded piece."
Simulations improve motorbike designs Padua, Italy--Eager to maintain its edge in technology and design, world-renowned Aprilia Motorcycle Co. asked Professor Vittore Cossalter of the University of Padua (Italy) and his students to tackle problems involving traction, vibration, and acceleration-induced pitching observed in scooters and racing motorcycles. With the help of Working Model 3D simulation software (Working Model Inc.; San Mateo, CA), Cossalter and his team are creating virtual prototypes and simulations that enable Aprilia to improve stability and safety in its models. Using Working Model 3D, Cossalter simulated the suspension of Aprilia's prototype scooter, code-named "Area 51," and its response to a variety of road conditions. To diminish road-induced oscillations, Cossalter reconfigured the suspension to significantly reduce unsprung weight, distributing load more evenly over the chassis. Road tests in subsequent physical prototypes verified the benefits of the reconfiguration, and Aprilia was able to minimize production times and the expense and time used for physical prototypes. Simulation in competition. In racing, any motion that prevents the competitor from reaching the finish line faster is motion wasted. That includes the occasionally severe pitching of a motorcycle front-end in rapid acceleration. With Working Model 2D and 3D, Cossalter's team simulated the transmission and suspension functions of Aprilia's Model 410 racing bike to test the effects of modifications to those systems. By simulating the effects of changes in tension, flexibility, and dimensions of components in the transmission and suspension systems, Cossalter's team made a series of modifications that effectively converted acceleration-induced momentum in the vertical axis to more manageable torque. As a consequence, the Model 410 is now faster in critical cornering maneuvers, improving overall lap times and rider safety. Stability in three. The quest for rider safety has inspired Cossalter's team to seek practical design solutions for future consumer vehicles--including a new three-wheeled vehicle concept. His three-wheeled concept is distinctive for its system linking the rear chassis, which bears the engine and main frame, to the forward chassis, which supports the steering mechanism, forks, and passenger. The linkage system serves a function similar to a ball joint, isolating rolling motion with the forward section of the chassis and keeping the rear section of the chassis level. The end result, according to Cossalter, is a vehicle that achieves vastly improved maneuverability while reducing the risk of roll-over and load shift. Working Model simulations have also revealed that the system can be safely configured to suit rider preference or application, or engineered to provide varying tension in response to the degree of force in a cornering maneuver. "Working Model 3D enabled us to consider this design thoroughly," says Cossalter. "The interface is easy to use and understand, which allows us to work and consider design iterations quickly; and the product is robust enough to perform reliably and error-free even in complex calculations." Saab 9-5 data
Engines*
2.3l 4 cyl.
3.0l V6
SAE hp
170 @5,500 rpm
200 @5,000 rpm
Peak torque (ft-lb)
207 @1,800-3,600 rpm
229 @2,100-4,000 rpm
EPA mileage (city/hwy mpg) w/auto. trans.
18/27
18/26
Transmissions
4-speed automatic with winter and sport modes
5-speed manual (2.3l only)
U.S. price as driven
(base/auto. trans./leather)
$32,420
*Both engines are turbocharged. The V6 is asymmetrically turbocharged: exhaust from three cylinders drives the turbocharger feeding all six cylinders. How do you compare?*
1990
1995
1998
All manufacturing industries
$49,300
$56,900
$65,100
Electric & electronics
(including computers)
$47,750
$55,700
$66,600
Chemicals, drugs & plastics
$57,950
$66,750
$69,800
Petroleum
$64,050
$71,400
$72,450
(MA degrees only)
Transportation equipment
(including aerospace & automotive)
Not available
$56,200
67,700
(MA degrees only)
*Median salary for engineers with 12 to 14 years of experience. Includes BS, MA, and Ph.D graduate in supervisory and non-supervisory positions.
Engineering salaries have risen steadily over the last several years.