As CAD grows,paper becomes design relic
Park Ridge, IL--A decade ago, experienced engineers responded with a knowing nod of the head when confronted with the concept of paperless design. Yes, they said, it was a nice idea. But not practical. And certainly not simple.
Now, however, that's changing. By some estimates, more than half of all new designs flow from computer programs with nary a scrap of paper. In the aerospace and automotive communities, that figure may be as high as 80%.
Even for the overwhelming majority of engineers who already use CAD, those figures are stunning. For years, the norm in many engineering offices has been "computer-assisted, paper-released." Now, a legion of engineers has taken the process a step further.
"Engineers used to spread out an assembly drawing and gather around a drawing board to review it," says Jim Daues, a former design engineer who spent 38 years with McDonnell Douglas before joining software supplier EDS Unigraphics , Maryland Heights, MO. "Now, they gather around a projection screen."
Chrysler's new 3.5 engine: By employing paperless techniques and simultaneous engineering, Chrysler engineers cut costs and shortened design time.
Sweeping changes. For many, the paperless revolution has yielded extraordinary benefits. At McDonnell Douglas, for example, paperless design produced a multitude of advantages on the newest F-18 fighter aircraft, called the Super Hornet. McDonnell Douglas officials say that the paperless process was directly responsible for a 75% reduction in engineering changes, a 25% reduction in tooling costs, and a 42% reduction in the number of parts. The company also claims it saved 300,000 man-hours and cut the weight of the aircraft by a thousand pounds.
Most impressive of all, however, was the reduction in defects. "The first vehicle had 40% fewer defects than the 1,200th vehicle of its predecessor," Daues says. The predecessor, the F/A-18C/D, was not paperless.
For most firms, such benefits are achieved only after sweeping changes. McDonnell Douglas, the prime contractor on the F/A-18E/F program, employed 425 CAD/CAM seats on the Super Hornet program alone. Northrop Grumman, also a contractor on the project, assigned 310 engineers to Hewlett-Packard workstations running CAD/CAM at its El Seguendo, CA, facility. All CAD/CAM stations at both sites used Unigraphics CAD/CAM software from EDS Unigraphics.
The most significant changes wrought by the paperless design phenomenon, however, are within engineering cultures. In all industries, engineers have discovered that concurrent engineering is a natural extension of paperless methods. In aerospace, where electrical and hydraulics engineers once joined a project during its late stages, all disciplines now work together from the outset.
Faster, less costly. Such was not the case a decade ago. Back then, paperless design and concurrent engineering were the norm in only a few isolated pockets. The reason: Most computer systems didn't possess the memory and processing capabilities to handle large assemblies involving thousands of components. Software, too, was more primitive. As a result, engineers often found that they needed to break products up into hundreds or thousands of digital pieces, which were usually defined by the computer's memory capacity. Assembling all those pieces and checking them for interferences was a task that called for substantial management skill. Hence, most big companies found it easier to employ the "computer-assisted, paper-released" approach.
Today, however, engineers have more powerful workstations at their disposal. And many available CAD/CAM software programs are set up for an all-digital approach. "You still have to break a large product up into zones," Daues says. "But the zones are larger and no longer defined by the computer's memory. If you use solids modeling, you also have automated interference checks."
Such capabilities have moved CAD/CAM to the realm of an all-encompassing solution, rather than a method for designing isolated parts. On the F/A-18E/F, engineers used CAD/CAM to design and review assembly layouts containing more than 30,000 parts. Sherpa Product Data Management (PDM) software from Sherpa Corp. was used to track changes on all of those parts. The software was customized for McDonnell Douglas and interfaced to Unigraphics by EDS.
Other big firms have also applied paperless techniques to similarly large projects. At Chrysler, engineers recently completed the design of a family of three new engines. Using a CATIA-based system and paperless techniques, Chrysler engineers report that they produced the engines in record time and for exceptionally low cost. The aluminum V-6 engines were developed in 98 weeks at a cost of about $625 million. In contrast, typical automotive engine development programs take about two-and-half years and cost about a billion dollars.
Chrysler engineers attribute development speed to the combination of simultaneous engineering and paperless design. "This is one of the few programs during my 27-year career where we didn't have a major re-do at the eleventh hour," notes Bruce Coventry, manager of advanced manufacturing for Chrysler's engine program.
Not a panacea. Similarly, engineers at Learjet employed a paperless approach in the design and development of the company's all-new Learjet 45. The electronic process provided Learjet with numerous advantages, but it was not without its difficulties, say Learjet engineers. The company's three major facilities--in Wichita, Canada, and Northern Ireland--all used different software (EDS Unigraphics' Unigraphics, IBM's CATIA, and Computervision's CADDS, respectively). As a result, engineers had to jointly develop interface software so that all three locations could share a common database.
As the project neared production, engineers also struggled with the task of making changes on the fly. "If you have one change and the drawing is tied up in the release process, you have to wait until that's finished to make another change," explains William Greer, vice president of engineering and quality assurance for Learjet. Because of the fast pace of the project, Greer says, Learjet eventually reverted to paper changes at the end.
Still, Greer says, the advantage of the digital approach outweighed the disadvantages. "The fit and analysis of the parts was excellent," he says. "The weight and the stresses were right on."
For reasons such as these, most engineers view the paperless approach as a technique that is here to stay. "For an existing product that wasn't designed electronically, it's not always best to re-load all the data," concludes Daues. "But for new programs, there's no reason to resist paperless engineering anymore."
What this means to you
• Shorten design times.
• Can cut costs.
• Work best in a culture that embraces concurrent engineering.
--Charles J. Murray, Senior Regional Editor
Valve handles hazardous chemicals
Vancouver, WA--The Department of Transportation has initiated a tough new regulation for bulk transportation vessels used with hazardous chemicals. In response, Technaflow Inc. has introduced a powder and bulk inverter valve that more than meets the new requirements, say company officials.
A key component of the Technaflow IBV-181 valve, which can be used to fill and empty powder, pellet, and granule bins and containers, is a high-strength, corrosion-resistant, dimensionally stable bushing made of Techtron® polyphenylene sulfide (PPS). The flange-bushing acts as a thrust-bearing component in the knife-gate valve's drive assembly. The high-strength PPS bushing withstands the valve's closing forces and vibrations during container transport.
Technaflow investigated numerous materials for the bushing before selecting the Techtron PPS from DSM Engineering Plastic Products, Reading, PA. "Since the bushing can come in contact with a wide range of chemically aggressive materials, we initially considered using a glass-reinforced PTFE (polytetrafluoroethylene)," says Andy McCutcheon, product engineer at Technaflow. "PTFE has excellent chemical resistance, but even with glass-fiber reinforcement, we found the PTFE bushing had low resistance to creep under prolonged high-compressive loads. Bushings machined from Techtron PPS have excellent chemical resistance, are strong, and stand up to cold flow."
In addition, the PPS exhibits good compressive and shear strength. Another benefit: high-impact strength relative to other products tested. For example, pulse wrenches are used to tighten the valve's drive nut. PPS bushings resist the sudden impact from these tools, even at low temperatures.
Hazardous container valve features a busing that can withstand chemicals, impacts and cold flows.
Plastic drives home nails
Woonsocket, RI--Pneumatic nail guns provide a convenient, speedy way for carpenters to attack major building projects. However, defective nail packs can gum up the whole operation. That's why a major OEM turned to a proprietary, mineral-filled polypropylene to form the strips that hold dozens of nails together for easy loading into the industrial-grade guns.
For the design, the OEM approached The Plastics Group of America with fairly rigorous performance specifications for the resin. The material had to grip the nails securely, and be strong and flexible enough to resist accidental breakage. It also had to snap off cleanly and reliably to release the nails when the gun is actuated.
In addition, the OEM required an unusually broad processing window. The existing low-tech production equipment utilizes no modern process controls. Continuous streams of molten resin simply drip from a tube onto a line of nails passing by on a moving conveyor. Furthermore, ambient temperature and humidity vary considerably in the plant.
Despite these impediments, the OEM demanded a single resin formulation that would work under all conditions. The solution: The Plastics Group's Polifil® polypropylene. The nail-gun strip formula resulted only after resin specialists at The Plastics Group experimented with different ratios of mineral fillers to achieve the right degree of stiffness. The special resin blend provided a fairly consistent melt index across a wide range of temperature and humidity variations. After the material proved successful in tests, the firm custom-colored it to the OEM's specification.
"Because the OEM's process is unsophisticated, we had to do some fairly sophisticated resin engineering to make it work," reports Mike Rosenthal, The Plastic Group's executive vice president for production. "But that's what this business is all about--meeting the customer's needs."
MMX boosts Pentium performance
Santa Clara, CA--Intel engineers gave the Pentium processor its latest performance boost by adding features to improve multimedia applications. Pentium processors with MMXTM technology achieve a 10 to 20% performance improvement on standard CPU benchmarks compared with Pentiums without the technology running at the same clock speed, say Intel officials. When running software specifically written for MMX technology, the performance increase can be up to 60%.
MMX technology includes three main architectural design enhancements:
• 57 new instructions designed to manipulate and process video, audio, and graphical data more efficiently.
• Single instruction, multiple data (SIMD) process, which lets one instruction perform the same function on multiple pieces of data. This lets the chip reduce compute-intensive loops common with video, audio, 3-D graphics, and animation.
• 32 kbytes of on-chip cache--double that of Pentium processors without MMX.
Performance for the 200-MHz desktop version is 6.41 SPECint95 and 4.66 SPECfp95; for the 166-MHz processor, the numbers are 5.59 and 4.30, respectively. Versions for laptops are also available at clock speeds of 150 and 166 MHz. Companies now offering both desktop and laptop computers powered by Pentium processors with MMX technology include: Compaq, Digital Equipment Corp., Gateway 2000, and IBM. A family of Pentium OverDrive processors with MMX technology will also be available this year.
EXPRESS Data Manager strides the Atlantic
Oslo, Norway--The I in IGES stands for "initial," which goes some way toward excusing some of the shortcomings of this graphics exchange standard. Long-awaited STEP (aka ISO 10303) promises to be a more comprehensive format for sharing 3-D data and attending documentation. A product out of Norway is demonstrating that vendors won't leave engineers out in the cold with their expectations.
International standards are composed of a blizzard of specifications. The ad hoc development of IGES fostered a "cafeteria-compliance" environment, some in industry say, wherein vendors could pick and choose what specifications to support and still wear the IGES label. STEP represents a sea-change in that the standard itself includes mechanisms to ensure compliance, such as the EXPRESS language for defining data models. "There is not as much opportunity to cheat the standard as there is with IGES," asserts Kjell Bengtsson, manager of sales and marketing at EPM Technology. "The EXPRESS language, like the rest of STEP, is more formally defined."
EPM Technology developed its EXPRESS Data Manager so software vendors and larger manufacturing companies can validate systems compliance with the published standard. The product consists of four main elements: a Server module for storing and manipulating EXPRESS schemata and product data; a Supervisor application for defining and maintaining the database; an API providing bindings with STEP's Standard Data Access Interface, which is used for messaging; and a Toolkit for compiling, parsing, formatting, and checking rules and constraints.
While CAD/CAM vendors are a major intended market for EXPRESS Data Manager, Bengtsson points out that manufacturing firms with large engineering staffs use the software to ensure STEP compliance. North American users of EXPRESS Data Manager include Lockheed Martin/Loral, Northrop Grumman, and Rockwell Collins. In particular, Bengtsson says these companies were interested in bringing their product data management (PDM) systems into step with ISO 10303.
Swedish defense contractor Hagglunds is supplying its CV-90 armored fighting vehicle (roughly corresponding to the U.S. Army's Bradley) to the Norwegian Army. The $300 million contract includes the usual provisions for maintenance and spare parts. EPM Technology is working with Hagglunds to make the latter's PDM system STEP-compliant. This will enable the Norwegians to exchange engineering and product data with Hagglunds, streamlining requests for parts, service, and design modifications.
'Octane' completes SGI's product-line overhaul
Mountain View, CA--After previously revamping its high- and low-end product lines, Silicon Graphics Inc. has completed the total overhaul of its technical computing family with the new mid-range Octane systems.
Octane features a crossbar internal communications system to replace older bus technology. Crossbars, once seen mostly on supercomputer-class machines, allow different parts of a computer system to share data more quickly. And, the crossbar allows multiple data transfers at once, instead of a single transaction common on bus-based systems. Octane features 1,600-Mbyte/sec data-transfer rates, versus 266 Mbytes/second for the older Indigo2 mid-range line.
SGI officials say the new Octane architecture offers 40 percent improvement on some industry benchmarks compared with Indigo2 , although both systems use the same processors. Increased system throughput also allows large, complex models to be handled much more easily--important for engineers seeking to do compute-intensive tasks such as simultaneous design and analysis. Robert Quinn at Parametric Technology Corp. says a 300-Mbyte Pro/ENGINEER file took only 5 minutes to load into an Octane machine, versus 30 minutes for an Indigo2 . "That's a huge capability on this system," he says.
Octane systems range from $24,995 for a single-processor (175-MHz R10000) system to $56,995 for a dual-processor (195-MHz R10000) version with a high-end graphics option.
Vacuum system ends 'hammering and headaches'
Louisville, OH--Until recently, the assembly team at VACUFLO® had to cut off, debur, spot-weld, glue, beat with a hammer, and notch steel inlet tubes in order to install them into central vacuum systems. The process required about three and a half minutes of installation time for the inlet tube--consisting of a steel tube, coupling, hose clamp, and gasket. The process also required an adhesive, which presented handling and ventilation considerations.
Now, with the help of a thermoplastic rubber, a new one-piece, flexible inlet tube requires only eight seconds to assemble. The tube is injection-molded from Santoprene® rubber supplied by Advanced Elastomer Systems, Akron, OH, then hand-assembled into the canister. The design eliminates the time-consuming installation process of the previous tube, as well as multiple tube components and the adhesive.
"The cumbersome inlet design that some of the industry still uses is 30 years old," says Jim Smith, VACUFLO engineering manager, H-P Products Inc. "With the help of Santoprene rubber, we've brought innovation to our cen-tral vacuums."
The 4.75-inch-long, 2.25-inch-wide flexible inlet tube enables 2-inch PVC pipe to connect with the central vacuum canister. It is injection-molded from Santoprene grade 101-64 thermoplastic elastomer (TPE), which resists flex fatigue. This flexibility also allows the material to be manually worked into the canister hole, rather than resorting to a hammer and notches associated with the previous metal design. Also, a molded-in flange creates a seal without adhesives or gaskets.
"Dented inlets used to be a problem when we used the steel tube design," Smith adds. "We received complaints too frequently about such problems. That has been completely eliminated since we changed to the rubber tube."
Synchronous drive's design slashes noise
Lincoln, NE--Goodyear has developed a new line of synchronous drives that produce 17 to 19 dBA less noise than conventional synchronous designs.
Scheduled for introduction at the National Design Engineering Show in March, the Eagle Pd drive system incorporates an offset helical-tooth design that, in addition to cutting noise generation, also reportedly reduces a synchronous drive system's energy consumption and maintenance costs.
Offset helical teeth permit the Eagle Pd synchronous drive system to operate more quietly than conventional straight-tooth synchronous belts.
Until the introduction of this drive system, according to Loren Danhauer, chief engineer, Power Transmission Group, Goodyear, all synchronous drives used a straight-tooth design. In such designs, every time a tooth enters a sprocket it impacts the sprocket and generates noise at a frequency related to tooth pitch and drive operating speed. In contrast, the new Eagle Pd system uses belts and sprockets with helical teeth. Consequently belt/sprocket interaction changes dramatically. "We call it continuous rolling engagement," explains Danhauer, "where the belt rolls into the sprocket. At any point in time you've got part of a tooth entering the sprocket, you never have one entire tooth entering."
About half the measured reduction in noise generated by the drive results from the design of the helical-tooth system. To obtain the rest of the noise reduction, engineers use two helixes on the drive's sprockets, and offset them by half a pitch. The offset right- and left-hand helixes somewhat resemble a broken letter "V", with the sides of the letter displaced vertically. Given the offset of the helical teeth, the sprocket's teeth cannot enter the belt simultaneously. Sound fronts generated by the left-hand helical teeth and right-hand helical teeth interfere destructively, thus reducing noise output significantly.
Operating-noise reduction, when compared to conventional synchronous belts, can reach 19dBA.
"If you draw a straight line across the sprocket, you have part of a tooth with a right helix and part with a left helix starting to engage the belt," says Danhauer. "And what it does is just roll in. It's like a zipper on a bag."
Helical gears and sprockets are certainly not new. But previous attempts to use helical teeth in synchronous drives encountered problems. "In each case they would use a helix, and when you run a helix the belt wants to track to one side," explains Danhauer. "They tried to use a flange to hold the belt on. And then you get some phenomenal side forces." In the Goodyear design, the left- and right-hand helical teeth generate equal and opposing forces that cancel out, so the drive does not require flanges--it becomes self-tracking. Eliminating flanges makes the drive lighter and physically smaller than previous designs that employed helical gear teeth.
Tooth design increases drive system capacity by eliminating the tendency of a typical belt to break where the tip of the sprocket engages it. At that location, the sprocket's tooth suddenly hits the belt all the way across its width, and in time the repeated impacts will fracture the belt's tension members. The helical-tooth design engages the belt more gradually, and this type of belt failure does not occur.
Goodyear has patented the use of helical offset teeth in the Eagle Pd system. In addition, the company developed and patented a unique manufacturing process to produce the system's belts. "As you go around the world and talk to various engineers, you discover that a lot of people thought of using this approach," says Danhauer. "But they couldn't figure out how to make the belt." He points out that manufacturers typically make straight-tooth synchronous belts on a metal drum and slide the completed belt off. The opposed helixes required new thinking to find ways of making the unique Eagle Pd belts. Danhauer refused to go into detail on the design of the manufacturing equipment used to make the new drive system's belts.
In addition to employing the new offset helical teeth, Goodyear engineers turned to new materials to increase belt load power transmission capacity and durability. Hibrex, the Eagle Pd's tooth compound, consists of a proprietary combination of materials. A high-durometer, high-tensile-strength material, Hibrex has a great deal of resistance to many oils. It also stands up well to cutting fluids, says Danhauer. Because of Hibrex, he asserts, the Eagle Pd belts "are probably a factor of ten times more resistant to cutting fluids than standard neoprene belts."
Belt tension members made from Flexten, an aramid fiber, enable Eagle Pd belts to maintain their length to within thousandths of an inch throughout their working lives, according to Danhauer. With that kind of stretch, a belt "is going to lose some tension, but not enough to hurt the functioning part of the system."
A facing material called Plioguard enhances tooth durability. Although Hibrex permits the drive system to handle high torque and high load, forces on the belt would abrade a standard facing. Danhauer describes Plioguard as a proprietary material that reduces the coefficient of friction of the facing. This reduction helps the facing resist abrasion during operation.
Initially, Eagle Pd drive system horsepower capacity ranges will extend from 0.05 to 550 hp. Greater capacities will be offered in the future. Although the company intends to concentrate on selling its standard systems, OEMs ordering in sufficient volume can obtain specials.
--Brian J. Hogan, Managing Editor
Surgeon fits reconstructive 'puzzle pieces' with rapid prototyping help
Dallas, TX--The same stereolithography technology that helps engineers preview their mechanical designs is helping surgeons plan how to best reconstruct human faces deformed by birth defects or accidents. And, just as in engineering, these rapid-prototyping techniques save valuable time.
"Being able to hold in our hands ahead of time, a complete three-dimensional model of the head, skeleton, and face, we are better able to plan surgery," says Dr. Ken Salyer, whose surgical team at the International Craniofacial Institute, Medical City Dallas Hospital, has operated on children from every state in the U.S. as well as from 57 other countries. "You can model plates and screws ahead of time. You can shape those parts. …What I do in my mind is now done with the mold." He can also test to see where best to make cuts, as well as use the models for training less-experienced surgeons on reconstructive techniques.
Salyer describes facial reconstruction surgery as "human sculpting. You have a puzzle in front of you. You have to move the bones into a new form, then you have to hold them together. …What I do is based on science, but it's much more art."
With the new process, Salyer sends a 3-D CT scan to Cyberform International, Richardson, TX, where a 3-D stereolithography model is created using a machine from 3D Systems, Valencia, CA. He says he can imagine the model in his mind while planning surgery, something physicians with less practice in such techniques might have trouble doing. However, even though he can visualize a patient's skull structure without a physical model, he can better check the stereolithography prototype to ensure there's enough room for cutting.
Before the prototypes were available, Salyer created 3-D computer or film images from hundreds of CT-scan "slices" of a patient. That gave some assistance in planning, but not exact size and spatial relationships among different facial features. "If you have it ahead of time, it makes surgery much more efficient."
Analyzer survives Mt. Everest avalanche
Mt. Everest, Himalayas--As a team of British medical researchers and their sherpa guides ascended the treacherous slopes of Mt. Everest, the mountain climber's worst nightmare became a reality. Millions of tons of snow and ice broke loose above them and came crashing down, engulfing the team's tents and scattering valuable test equipment over a wide area.
Miraculously, no one among the party was injured. Perhaps equally miraculous, the intricate, sensitive electronic analyzer they carried with them suffered no damage.
The team spent several days gathering supplies, digging out equipment, and assessing damage. One of their finds was a crushed box that had borne the full brunt of the avalanche's impact. Inside was the blood gas analyzer. It was saved by Polylam® Laminated Foam packaging material made by Sealed Air Corp., Saddle Brook, NJ. The Ciba-Corn-ing model 248 analyzer then had to withstand -20F temperatures and frequent snow during the remainder of the 17-day expedition. It operated flawlessly.
The medical team had brought the analyzer to research breathing control, balance and orientation, heart rate, high-altitude pulmonary edema, and several other medical aspects of harsh weather. Following the mission, the analyzer was shipped to customers in all corners of the globe. During this time, it continued to withstand the rigors of multiple handling, including warehouses, freight forwarding, aircargo, and repacking after prospective customer demonstrations.
"We regularly check on the analyzer," says David A. Verghese, business manager, clinical products, Ciba-Corning. "Our warehouse tells us that after 18 months of travel, the analyzer hasn't experienced any problems in the field. The laminated foam continues to provide the strong, protective packaging to meet our varied global needs."
CFD proves golf club's advantage
Chicago, IL--Wilson Sporting Goods proved its Invex golf clubs are aerodynamically superior to other clubs through mechanical testing and play testing by 100 golfers. But Wilson wanted to demonstrate the clubs' advantage in a way that would catch people's attention.
Wind-tunnel testing of the Invex against competing clubs was ruled out as too expensive. Instead, the company performed a virtual wind-tunnel test using Flotran computation fluid dynamics software from Houston, PA-based ANSYS, Inc. In addition to the Invex clubs, engineers simulated aerodynamic performance of a Calloway Big Bertha and a Taylor Made Burner.
After transferring 2-D CAD models of the club heads into Flotran, engineers set up a simulation by supplying information such as club-head velocity and club orientation. The software then simulated air flow over the club during a typical swing. Results were portrayed graphically using color-coded "stream lines."
The stream lines followed the Invex club very closely, and there were no recirculation eddies behind the club. In contrast, both the Big Bertha and the Burner had these eddies, which indicate a more turbulent air flow caused by drag.
The numerical results of the air-flow analysis showed the Invex club experienced significantly less drag compared to other clubs. This means the Invex will deliver both greater distance and better accuracy. Explains Ed Hinka, director of golf club research and development at Wilson, "Club-head speed determines distance. Golfers can always swing harder to get more distance, but there's a trade-off. They also need accuracy. The Invex's lower resistance enables golfers to get the club head down to a ball quicker. But since there is also less turbulence, the club face is squarer at impact, which helps accuracy."
Have you driven a fjord, lately?
Kirkenes, Norway--The province of Finnmark is having its warmest winter since 1944, the year the retreating Germans burned everything in sight. It is a positively balmy -5C, not exactly the forbidding survival test Volvo envisioned for its new S70 and V70 lines.
Oh well. The sun is never more than a reddish horizon smear for about two hours a day. This becomes problematic behind the wheel of the S70 sedan when I cannot find the dashboard lights.
A few ergonomic criticisms, which I will dispose of quickly: The dash controls are impenetrable to the naked eye. You actually have to read the driver's manual, which is anathema to many Americans. The audio system has a vast array of buttons too distracting for a driver to absorb on the fly. And the navigator cannot exercise his secondary function of music director without fouling the driver's shifting. I could not find the cup holder, but Volvo style manager Rolf Malmgren told me it was there, cleverly retracted, somewhere.
Style-wise, the new Volvos edge ever away from that "boxy-but-good" reputation, just leaving the good. The hood slopes rakishly and merges with the upright grille, headlights, and bumper. The backsides are still Volvo-esque, however.
We head south on E6 to 886 East, which grazes the Russian border at several points and terminates at the Barents Sea. The road is well-paved but narrow, and winds through some truly forbidding--and beautiful--Arctic terrain. The route outlines the frozen fingertip of a fjord and climbs inland. Mountains are not particularly tall, but numerous and quite rugged: almost walls. Frozen streams and lakes abound. We receive friendly waves and toothless smiles from locals preparing to ice fish.
I dare not find out how fast the S70's 2.5l, five-cylinder, high-pressure turbo will go. In fact, I only rarely get out of third gear and never make it to fifth. They don't believe in guard rails in Norway. I consider how Volvo has built on its trademark safety features with a reinforced B-pillar designed to provide enough time in an accident for the side-impact air bag to deploy. A three-part steering column will collapse in a crash.
Day two is ice driving, which begins after a breakfast of reindeer soup at a test track near the borders with Finland and Russia. Malmgren demonstrates that his abilities as a rally driver are at least equal to his design skills. He hurtles his V70 wagon sideways through slick turns and roars down the icy straightaways. The V70 quickly becomes the ice-track car of choice. The all-wheel drive (AWD) holds turns firmly (and the studded tires don't hurt, no doubt) enabling the five-cylinder, light-pressure turbo to muscle through them.
Volvo's AWD system has a viscous clutch that transfers power to the rear wheels before the front pair can start spinning. Furthermore, traction control on the front wheels and a locking differential system on the rear prevent any one wheel from spinning on its own.
The wagons in our hands are five-speed manuals, and shift smoothly entering and exiting turns. Volvo is positioning the V70 as its current alternative to the becalmed sport utility. The ones available Stateside will only have a 4-speed automatic; Canadians, however, rate the five-speed stick.
The seat warmers on all models are a revelation, although they only have one setting: broil. Later in the day we prudently turn them off while idling on a frozen lake, awaiting our turn on an ad hoc track Volvo has plowed in the snow. Now I've got the light-pressure turbo version of the S70. Freed of any terrain considerations--excepting the background concern of plunging through the ice--I can really have my way with the car.
In total darkness (I still can't find the dash lights), I live an adolescent fantasy of skids, slides, slips, and snow-slinging recoveries. The extra kick of the high-pressure turbo is not missed in these conditions. Traction is superb; acceleration and breaking are immediate; steering is confident.
The S70 and V70 Volvos will be available in the U.S. starting in March. Pricing is reportedly to be just slightly higher than for the 850 line they replace: between $27,000 and $35,000.
--Michael Puttré, Associate Editor
Composite eases underwater photography
San Luis Obispo, CA--When photographers work underwater, they need a light source once they get below 10 feet. For this purpose, they rely on a strobe arm assembly to position the lights. Making this task easier is a new, lightweight arm assembly designed by Ocean Brite Systems and molded from a long-glass, fiber-reinforced thermoplastic structural composite.
"A lightweight strobe arm is extremely important to the photographer because the assembly is a portable piece of equipment," comments Jim Bullitt, a partner in Ocean Brite Systems. "The composite material makes the arm easier to travel with, assemble, and use."
For the project, Ocean Brite selected Verton® MFX, a long-glass, fiber-reinforced polypropylene structural composite supplied by LNP Engineering Plastics, Exton, PA. The thermoplastic assembly costs less than conventional aluminum systems, is lighter, and has zero corrosion, according to Bullitt.
When designing the new assembly, Ocean Brite looked for a material that would be as strong as aluminum. "With the Verton composite, even our longest arms are 10% stronger than arms on aluminum systems," Bullitt reports. "This means the strobes and lights won't droop--even in a two-knot cur-rent. And, unlike aluminum, they won't corrode."
Simulation scratches single-step stamp
Frankfurt, Germany--Engineers at Adam Opel AG were hoping to stamp out extra steps in the manufacture of suspension housings. In fact, they worked out a way to deep-draw parts with just one operation--theoretically.
The suspension housings consist of two symmetrical left and right components. They were to be stamped with a die as a single piece and subsequently cut in half. The piece was quite thin--2 mm--and safety requirements dictated the stamping operation had to result in a 10% thickness reduction or less. The question for designers: whether this condition could be satisfied in a more economical one-step process. In addition, they had to determine appropriate die radii, blank-holder loads, lubrication conditions, and sheet cut.
Try-out dies are expensive, so engineers turned to simulation to test their concepts. CAD data was loaded into the PAM-STAMP simulation software program from Engineering Systems International Corp., Troy, MI, via the European-standard VDA file format. Analysts meshed the punch, die, holder, and sheet separately. Material properties came from standard handbooks.
The most difficult aspect of the process from a modeling standpoint is the interaction of the blank and tools. PAM-STAMP models material flow using very small time steps, and employs an explicit integration technique and contact algorithms that search for correspondence between mesh nodes and elements and then calculate contact forces.
Engineers ran a number of simulations of one-step stamping processes varying die radii, lubrication conditions, and sheet dimensions. Unfortunately, every technique predicted the part would either split as a result of a one-step process or exceed the 10% thickness change requirement. In order to check the accuracy of the simulation, engineers performed a series of physical tests of one-step operations using try-out dies. The parts either split or did not conform to specifications, as predicted by the simulation.
As a result, Opel abandoned its search for a one-step process for making suspension housings and devised a two-step process instead that has yielded satisfactory results. The exercise also suggests that no matter how good a simulation is, some engineers cannot resist breaking real things before declaring an approach invalid.