Racecar with composite-intensive suspension gets track tested in 2015

The tangy yellow-colored 1986 Honda CRX emblazoned with SANLUIS Rassini on its hood uses a patents-pending rear suspension as a replacement to its most recent setup of coil-over-springs and a straight axle with a Mumford linkage for lateral control.

“We’ve converted it to a dual-cantilever thermoplastic spring in the rear. It’s very similar to a double-wishbone geometry. The thermoplastic upper control arms are coupled with what’s very similar to a Watt’s linkage. That means during a two-wheel bump, the rear wheels move together. But when the car goes into roll, the coupling linkage locks the arms and those arms flex to add roll stiffness,” Jonathan Spiegel, Polystrand Inc.’s Senior Engineer, told Automotive Engineering.

The racecar will compete in the Sports Car Club of America’s (SCCA) Grand Touring Lite (GTL) 2015 race season on various tracks in the U.S. Project GTL partners are Polystrand, PPG Fiber Glass, the University of Alabama at Birmingham (UAB), and SANLUIS Rassini.

Polystrand provided the thermoplastic composite material. PPG supplied the continuous fibers for reinforcement of the thermoplastic material. UAB conducted materials property evaluation and molded the glass-reinforced springs and upper control arms, while SANLUIS Rassini handled suspension modeling, fabrication work, as well as final rear suspension assembly.

The racecar will compete against other purpose-built, highly modified series production sports cars, starting in the spring of 2015.

“We’ll be putting the rear suspension system under a real torture test. If we run the minimum number of SCCA’s GTL races, the suspension will experience several thousand miles of racing. Each race means continual high-stress on these lightweight, recyclable components,” said Spiegel, who designed the racecar’s suspension layout.

Bob Friedrichs, SANLUIS Rassini’s Vice President Engineering Suspension Group North America, noted that “the development of the GTL project in collaboration with Polystrand and PPG is an important one. It allows for testing of new continuous fiber thermoplastic technology for suspension springs and provides us with a lot of [vehicle] limit handling data in a short period of time.”

Spiegel estimates that the front-wheel-drive racecar shed more than 100 lb (45 kg) by replacing its all-steel rear suspension with a configuration featuring glass-reinforced nylon 6 springs and upper control arms attached to a steel subframe.

“The suspension loads are now fed directly into the frame structure rather than being in the unibody, so the car no longer needs all that supporting structure. In a production car that supporting structure would take up rear-passenger compartment volume and trunk space,” said Spiegel. “The prototype suspension not only reduces the mass but we can put what mass there is down lower, so that will help with the car’s handling.”

For SANLUIS Rassini, the world’s largest designer and manufacturer of leaf springs for light-duty vehicles, developing lightweight suspension components for future production applications is important. According to Friedrichs, “A commercially viable composites-intensive suspension for passenger cars would absolutely be a game changer.”

Weight savings between 30-40% are possible. “The implication that would have on lightweighting and CAFE standards would be huge,” Friedrichs noted.

3D-printed high-temperature ceramics

Heat-resistant ceramics are useful for making components such as engine hot parts, rocket nozzles, and nose cones that have to contend with high temperatures or extreme environments. The trouble is it’s not at all easy to cast or machine these heat-stable engineering ceramics into the necessary complex shapes.

In recent years, 3D-printing processes have been developed that enable much greater geometrical flexibility in fabricating ceramics. But whether the process deposits photosensitive resins that contain ceramic particles, jets binders onto ceramic particles, or fuses beds of ceramic powder with lasers, current additive manufacturing (AM) methods are limited by slow fabrication rates. Plus, they are often followed by a time-consuming binder-removal process. In any case, the physical properties of the final components are not optimal, yielding unreliable, low-strength parts that suffer from residual porosity, cracks, and/or inhomogeneities.

A new AM technique developed at HRL Laboratories, an R&D lab in Malibu, CA, that is jointly owned by General Motors and Boeing, has demonstrated the ability to make high-strength ceramic components featuring complex geometries more easily and rapidly. HRL’s Senior Chemical Engineer Zak Eckel and Senior Chemist Chaoyin Zhou have invented a polymer resin formulation that can be 3D-printed into green parts with complex geometries and then fired in a furnace where they pyrolyze with uniform shrinkage into high-density ceramics.

“With our new 3D-printing process we can take full advantage of the many desirable properties of this silicon oxycarbide ceramic, including high hardness, strength, and temperature capability as well as resistance to abrasion and corrosion,” said HRL program manager Tobias Schaedler when the new technology was unveiled. Such cellular ceramic materials are of interest for the core of lightweight, load-bearing ceramic sandwich panels for high-temperature applications—for example, in hypersonic vehicles and jet engines.

Printing preceramic monomers

“We go straight from printing the preceramic polymer to fully dense parts,” Eckel said. “The first method is stereolithography, where we solidify, polymerize a special ultraviolet (UV) curable preceramic resin and a UV photo initiator with a laser to form complex shapes, but this still takes hours or even days.”

That’s why the HRL team focused as well on a home-grown technique that produces green parts much more quickly in larger volumes. As part of a decade-long DARPA contract to develop lightweight, high-strength materials, he explained, researchers had developed a way “to funnel the UV light all the way down to the bottom” of the precursor resin tank, allowing much faster builds.

The trick is to solidify material by shining a UV lamp simultaneously through the holes in a lithographic mask while at the same time collimating the light within the illuminated shafts to harden all the way to the bottom. In this “self-propagating photopolymer waveguide method” the light penetrates via a waveguide effect based on successive downward reflections off the internal surfaces of the resin column. This process has created uniquely lightweight but strong truss structures, for instance.

“We produced an ultralight nickel microlattice that for awhile was the world’s lightest material; now it’s the world’s lightest metal material.”

Multiple ceramic recipes

Today they’re applying the alternative additive fabrication technique to high-temperature ceramic components.

Both UV hardening processes can ultimately produce many different ceramic materials, but for a start the team has demonstrated a silicon oxycarbide ceramic shaped into an intricately porous, lightweight structure that can withstand ultrahigh temperatures in excess of 1700°C (3092°F) and exhibits strength ten times higher than similar cellular ceramic materials, Eckel said.

“Technically, the amorphous glass microstructure is sort of a hybrid of glass and carbides; at the nanoscale it’s segregated into tiny silicon oxide regions surrounded by graphite layers,” he explained.

“We’re leveraging a certain special chemistry here,” Eckel continued. “Preceramic polymers and polymer-derived ceramics are pretty common. This class of materials was first developed in the 1960s.”

When heat treated to 1000°C (1832°F) under an inert atmosphere such as argon, they pyrolyze, forming many ceramic compounds including silicon carbide, silicon nitride, boron nitride, aluminum nitride, and various carbonitrides. At the same time, volatile chemical species such as methane, hydrogen, carbon dioxide, water, and hydrocarbons “cook off,” leaving the mostly densified, shrunken-down ceramic shape behind.

By attaching various organic molecular groups to an inorganic silicon- or carbon-based backbone such as a siloxane, silazane, or carbosilane, the research team can formulate the UV-active pre-ceramic monomers that crosslink strongly when suitably illuminated.

Uniform shrinkage

In the test reported in their paper, “Additive Manufacturing of Polymer Derived Ceramics” in the January 1st issue of Science magazine, the silicon oxycarbide precursor pattern experienced a substantial 42% mass loss and 30% linear shrinkage during conversion in the furnace. But the team described the shrinkage as “remarkably uniform,” almost like the storied shrunken heads of South Sea headhunters of yore, the relative proportions of the shrunken objects’ features remain the same.

The NRL team has used the ceramic fab technology to produce thin-element truss structures—demoing multiple microstructures, honeycombs, re-entrant honeycombs—that exhibit surprising degrees of flexibility. They’ve also built everything from corkscrews to rocket nozzles, missile nose cones, gas turbine engine blades, and micro impellers.

Additive manufacturing of such polymer-derived ceramic materials is not only of interest for propulsion components for jet engines and hypersonic vehicles, but thermal protection systems, porous burners, microelectromechanical systems, and electronic device packaging as well. HRL said that it is looking for a commercialization partner for this technology.

Ohio State’s ‘Bullet’ EV has a short range, but could surpass 400 mph

There were several electric vehicles (EVs) on display at the New York International Auto Show, but one of them is 38 ft (11.6 m) long, and weighs 8000 lb (3630 kg). It has a cockpit for just the driver, and will be trying to push the land speed record for an EV to over 400 mph at the Bonneville, UT, Salt Flats this August.

Image: aei-OSU-ev-a-415.jpg

It’s a college student project, but there’s no reason to sell the engineering team short. They are graduate students in Ohio State University’s Center for Automotive Research (CAR), which holds the existing world EV record—307 mph.

The team is working with a premier engineering company, Venturi Monaco, a racing EV team with a solid record of success, and is using a new generation of 2000 lithium-ion-phosphate pouch cells from A123 Systems. The total pack capacity is 100 kW·h and the weight is 3400 lb (1542 kg). Although the cells are similar to other A123 pouch cells, the ones in the “Bullet” EV’s pack are not yet commercially available, according to student team leader David Cooke.

Latest in “Bullet” series

This EV is the fourth in OSU’s Bullet series, although designated Bullet 3. No. 1 was an EV with nickel metal-hydride batteries, No. 2 was a hydrogen fuel-cell vehicle, and No. 2.5 was a first effort with Li-ion batteries (32,113 cylindrical cells from A123) and is the holder of the existing world record.

The Bullet body is carbon fiber, mounted on a steel space frame. The coefficient of drag is just 0.127, thanks to an extreme effort at tapering the body sides and a driver “seating” position that is nearly horizontal.

“We had to justify everything that might increase the width, even screw heads,” said Evan Maley, a member of the student team. The body was designed at OSU by masters degree students, with CFD assistance from TotalSim USA.

To reduce width, the Bullet 3 uses one centrally located electric motor for each (front and rear) axle of the four-wheel-drive system, instead of a motor at each wheel. The battery pack has been tested for full power. However, the electrical system, including its two 10,500-rpm peak-rated permanent magnet synchronous motors, has only been tested to 2.1 MW (2816 hp), although design-rated for a total of 3000 hp (2238 kW).

With continued tweaking of the inverters and motor control, the Bullet 3 team expects to reach the full design power, Cooke said.

Powertrain by Venturi Monaco

Basic development of the powertrain, including the motors, was done by Venturi Monaco, with the student team performing the integration work. Venturi’s area of expertise is engineering for environmentally oriented racing, and it has developed EVs, hybrids, and biofuel vehicles.

The 24.5-in (622-mm) wheels are of forged bullet aluminum, No. 7075 alloy, a high-strength aircraft grade aluminum that gets both a pre- and post-treatment. The tires are a special ultra-lightweight design by Mickey Thompson Performance Tires & Wheels, and have only 0.0625-in (1.6-mm) of tread rubber.

In a track run, there is up to 1.5 in (38 mm) of growth in the diameter of the wheel-tire assembly, Maley said. This change creates a significant challenge for the electronic control system for the drivetrain, which needs precise information on the speed of the vehicle.

The carbon-fiber body and the high power outputs (which create interference) limit the use of wireless to a GPS signal, which in conjunction with a six-axis accelerometer detects all wheel motion to correct the GPS signal. In addition, there is an airspeed signal as a backup, using a bank of pitot tubes—a variant of the airspeed indicators in planes.

Two-speed transmission

The Bullet 3 has a two-speed transmission, so when the driver requests a shift, the control system slows each motor and then commands the shift. The computer next gradually raises motor speed at a rate of 1000 rpm per second, and at a specific rpm an overrunning clutch engages—a mechanical operation.

The motor is cooled by automatic transmission fluid, which is chilled immediately before the run to reduce its temperature to 25-30°C (77-86°F). During the run, the oil in the motor will rise to about 130°C (266°F).

The clutch and gearbox are not subject to high temperatures, so light racing gear oil is circulated, primarily to lubricate the bearings and reduce friction between gear teeth.

Motor electronics “ice” cooling

The motor electronics require active cooling. The circuit is filled with water, then is partly drained, leaving just enough to keep the pump primed. The system then is filled with ice chips just before the run, and by the time the run is over, all the ice will have melted.

Vehicle weight “is not your friend when you’re trying to accelerate,” noted Cooke. But he pointed out that the coefficient of friction of the Salt Flats course is just 0.3 to 0.6, which provides half the grip of asphalt. So if the vehicle is too light, there’s a traction issue, Cooke added. However, to get the overall performance needed, the Bullet 3 is heavier than what the team would consider ideal from a standpoint of what is required for traction.

Because acceleration is so important, in the drawing-board phase the OSU team did look at capacitors, which discharge more quickly. However, the batteries chosen maintain a relatively flat voltage curve as they discharge, going from 20% to 90% depletion with little voltage drop, he added. So on balance, they were the best choice, Cooke said.

The braking system uses a combination of aircraft disc brakes and two parachutes to stop the car.

FIA rules for record

The rules for the world land speed record in miles per hour (there also can be runs for a record in kilometers) are set by FIA (Federation Internationale de l’Automobile). Speed is measured over a mile—between mile 5.5 and 6.5 on the 12-mi Bonneville course. The car is run both ways on the same course within an hour, and the two numbers are averaged.

When the vehicle completes its first run, the team has a brief period to prepare for the second run, including recharging the battery pack. There isn’t enough time for a full recharge, Maley said, but it takes only about 20 min for a 20-90+%. So the overall sizing of the battery pack factors this into the design. The charging operation uses a diesel generator (rated at 150 kVA) feeding through a dc battery supply, with the charge rate regulated by a control system from a laptop.

The driver will be Roger Schoer, the performance driver and instructor at the track of the East Liberty, OH, Transportation Research Center, where the OSU team does some of its testing.

Ohio State’s CAR began its EV program by participating in the open wheel Formula Lightning college series that ran through the 1990s. It also has been a participant in Formula SAE, Supermileage SAE, and Baja SAE programs.

Kettering FSAE team improved as season progressed

This year brought many new challenges to the Kettering University Formula SAE team. Since the team’s previous chief engineer had left and other core members had graduated, members knew that it was going to be an uphill battle coming into this competition season.

Additional challenges arose when the team decided to switch to ten-in wheels from the old, heavy thirteens that GMI2014’s predecessors wore (GMI is a reference to General Motors Institute, the former name of Kettering University). With new members coming aboard and a redesign of key parts such as the chassis, uprights, suspension, and brakes, this year tested not only the team’s engineering skills, but also its patience.

A Kettering strength

After completing GMI2014 and having a few days to test it, the story of the Kettering University Formula SAE team’s competition at Michigan International Speedway (MIS) began. Arriving at MIS on Thursday (May 15) morning, sleep-deprived and teeth-stained from coffee, team members quickly got ready for the static events while preparing to go through technical inspection. The first event for the team was the cost event. There, the judges looked over the team’s car and picked over things that were not in the cost report—things that otherwise would have gone unnoticed. Walking away from the audit, the team placed the highest in any event that it would at MIS with a respectable sixth place.

The next stop for the team was the design event. Having an all-new design with very few days of testing meant that the theoretical data was there, but there was hardly any test data. Despite lacking the test data of a new design, the team came out 38th overall, tying with some other teams.

The last static event on tap for the team was the business presentation. After finishing 52nd in the event last year, the 2014 Kettering team business presenters were able to pitch the team to 12th place for the event, an improvement of 40 places. Placing quite well in the static events, it was clear that the Kettering University Formula SAE team was unable to be stopped…or so it seemed.

Problems with Percy

During the mandatory technical inspection, the team had a hard time getting Percy (the name of the template representing a person sitting in a Formula SAE vehicle) to fit comfortably in the car. Unfortunately, by the time the team passed tech inspection on Friday, the acceleration and skid pad events had come to a close. But the team was able to get the car through the tilt, noise, and brake tests, and was able to compete in the autocross event held that afternoon.

Managing to do well enough in the autocross event to land the team’s car in the 33rd spot for the endurance event to be held the next day allowed members of the team to sleep comfortably Friday night.

But the next day was full of surprises.

Saturday brought the highest-weighted event: endurance. While this year’s endurance event at MIS had some surprising occurrences such as three car fires and less than half of the field finishing the event, the Kettering University Formula SAE team’s car came out in full force. Unfortunately, a little over halfway through the team’s swing at endurance, the car ran out of gas. This was puzzling because the Kettering team’s car won fuel economy last year. The team bounced into action getting the car back into the paddocks so that the problem could be diagnosed.

The good news

What may have turned out to be a problematic issue turned out to be a simple one.

“The main issue with the vehicle at Michigan [International Speedway] was an issue with the ECU code,” commented the Kettering University Formula SAE team chief engineer Adam Watson. For the 2014 season, it was decided to use a new adaptive O2 sensor. This allows the fuel map to continuously update to refine itself based on the feedback from the O2 sensor. While this would normally be a positive change to the vehicle, removing the O2 sensor and turning off the adaptive O2 instead of just disabling the adaptive O2 can cause the fuel map to continuously adapt to a fixed feedback value, which is incorrect.

That is, unfortunately, what the Kettering University Formula SAE team did. Without disabling the adaptive O2, the ECU kept injecting more and more fuel into the combustion chamber every lap until the car ran out of fuel. At the time that the car did so, it was just over halfway through the endurance event. The car had to be towed off of the course.

After finding out what went wrong, the Kettering team set its focus on the Formula SAE competition in Lincoln, NE. The team also made some adjustments to its vehicle.

“For Lincoln, we tested many combinations of camber, toe, springs, and roll center to tune the chassis for the different dynamic events,” explained Watson.

By testing the different combinations, the team nailed the different vehicle setups needed for the dynamic events. The team also gave the car more curb appeal by powder-coating the chassis white. This required the car to be disassembled before powder coating and then reassembled. In addition, more data was acquired during the time between the two competitions for the static events, especially for the design event, through more testing.

Despite not having a stellar performance at MIS like it did last year, it was evident that the Kettering University Formula SAE team brought some lessons home to learn from. Still, finishing 62nd overall with one of the lowest-priced cars at the competition is nothing to be upset about and proves that the lowest-priced car is certainly not the worst car. That is especially so considering that most of the parts of the car were completely redesigned and the car was partially built by new team members.

What the Kettering team learned at MIS was used as a basis for preparing the car for the Lincoln competition, where the team took 1st in fuel efficiency, 2nd in cost, 11th in endurance and, along with winning Nucor Steel’s Pay for Performance Award for the second year in a row, 10th overall.

Charles Mancino, a junior studying mechanical engineering at Kettering University, wrote this article for MOMENTUM. He has been on the Kettering University Formula SAE team since his freshman year and has been an instrumental part in designing and building the university’s Formula SAE vehicles. He is also the vice president of the Kettering University A-Section Firebirds Club, a member of the Kettering University student-run newspaper, a tour guide at Kettering University, and a blog writer for the university.

Tesla applies for dealership license in Michigan

Tesla Motors Inc. has applied for a Michigan dealership license, a move the automaker said is intended to test a state law effectively banning the electric-vehicle maker’s direct-sales model.

A decision on the application is expected within two months, Michigan Secretary of State spokesman Fred Woodhams said today.

Tesla applied for the license in November, about a year after Gov. Rick Snyder signed a bill prohibiting the direct sale of vehicles from automakers to consumers.

The application is a way of testing the state’s seriousness in enforcing the law, a Tesla spokeswoman wrote in an email to Automotive News.

“As recently amended, current Michigan law prohibits Tesla from being able to license its own sales and service operations in the state,” the spokeswoman wrote. “Submission of the application is intended to seek the secretary of state’s confirmation of this prohibition. Once confirmed, Tesla will review any options available to overturn this anti-consumer law.”

Tesla applied for a Class A dealership license, which would allow the company to sell new and used vehicles if approved, Woodhams said. A Class A dealership also must have an on-site repair center or be affiliated with a third-party repair operation, Woodhams said.

He said Tesla supplied the secretary of state’s office with additional information late last week after the office requested it. It is unclear what information was sought, but Woodhams said it is typical for an applicant to be asked for more information.

In October 2014, Snyder signed a bill into law banning the direct sale of vehicles from automakers to consumers. The bill passed both houses of the Legislature with one combined “no” vote, closing a loophole that allowed Tesla and others to operate in the state.

Tesla called the bill, backed by the Michigan Automobile Dealers Association, “a raw deal” when it passed the Legislature. The language banning direct sales was added at the last minute to the bill, which initially was written to ensure that dealers could tack additional fees on to the purchase price of vehicles sold in the state.

Palo Alto, Calif.-based Tesla also has fought to crack into other states where direct sales are banned, including Texas. While it has not had success in tilting public policy in its favor in Michigan or Texas, Tesla succeeded in 2015 in getting Georgia, Maryland and New Jersey to allow direct sales.

Arvind Saxena appointed as MD of Volkswagen Passenger Cars in India

a leading German car manufacturer has announced Arvind Saxena as the managing director of Volkswagen Passenger Cars in India.

Saxena, former director, sales & marketing at Hyundai India, will now be heading the Volkswagen brand with responsibility of sales, after sales & marketing, said the statement issued by the company on Wednesday.

ET had exclusively reported in July that Saxena was looking at growth options with leading automotive companies in the country including Volkswagen India.

Gerry Dorizas, president & MD, Volkswagen Group Sales India Private Limited said, “”We are confident that his (Saxena’s) extensive experience in the Indian automotive sector will contribute towards the growth of the Brand.””

With the appointment of Saxena, Volkswagen has created a new position of managing director in the company. He will manage the function of Neeraj Garg, who was member of board, director – passenger cars, Volkswagen Group Sales India Private Limited.

With over 3 decades of experience in the automotive industry, Saxena has worked for various automobile majors like Bajaj Auto, Maruti Suzuki, Fiat India and Hyundai India. He has assumed various roles right from area manager, regional marketing manager, general manager, dealer development, chief general manager sales, VP sales & marketing to director & member of Board at Hyundai India, when he made this move.

This appointment is part of the major churn in the automotive industry. Just last week, Tata Motors appointed Karl Slym as the managing director of the company.Ford India has appointed Vinay Piparsania as the new executive director, marketing, sales and service, who is likely to take charge from 1 stof September from Nigel Wark.

And Nissan’s marketing arm Hover Automotive recently recalled Nitish Tipnis to lead sales and marketing role, taking charge from Dinesh Jain. Hyundai India will now be on the look out to replace Arvind Saxena’s position.

Hella’s vehicle-damage detection technology moves toward production

A technology that uses acoustic signals to detect vehicle exterior damage can use the connected car network to inform the driver’s smartphone that the vehicle has sustained a dent, scratch, or other harmful hit.

“Intelligent Damage Detection (IDD) is a great example of how you can connect the vehicle with the user beyond just the normal driving applications,” noted Dr. Marc Rosenmayr, CEO of Electronics North and South America for Hella Electronics Corp. “This technology works not only when you are driving, but it works if you are away from the car,”

After more than 18 months of advanced engineering work that included a pre-development project with a European automaker, Hella’s IDD technology is now in the series production development stage, Dr. Rosenmayr told Automotive Engineering.

The springboard for IDD is Hella’s Structural Health And Knock Emission (SHAKE), which provides the basic hardware and software foundation for different functions and applications, according to lead engineer Klaas Hauke Baumgärtel.

“One of these applications is the function of IDD, which allows for the identification of scratches and dents on the outer shell of the vehicle in real-time,” he explained. In a connected vehicle application, an immediate damage notice could be messaged to the driver’s smartphone, an automotive dealership, police, or another source.

Hella’s engineering team has performed numerous destructive tests in the lab and on the road as a means of distinguishing vehicle damage vibrational patterns from those of non-damaging car sound patterns.

IDD’s intelligence relates to the precise interpretation and classification of sensor-identified acoustic signals, and how those inputs correlate to a scratch, a dent, or a slammed door.

“It took us several years to develop such a competence,” Baumgärtel noted. “It was an ambitious task to find a combination of signal features to separate all of the non-damaging and damaging signals. But finally, we have made it.”

Depending on the vehicle application, between four and 11 sensors are used to obtain acoustic signals from the car’s outer panels.

“Each sensor unit contains a small control unit for the analysis, interpretation, and classification of the signals. Based on this decentralized approach, each sensor is able to judge the signal and only delivers an incident message to the body control module or comfort control module if the signal has been classified as critical,” explained Baumgärtel.

Virtual vehicle observation technology is gaining industry traction. For instance, BMW reported on its ‘Bumper Detect’ sensor system R&D work during the 2016 Consumer Electronics Show.

Hella’s damage detection technology relies on acoustic sensors. “For this application field, we found out [through in-house testing] that other sensor technologies are not precise enough and have a different focus of detection,” Baumgärtel said. While ultrasonic and radar are good at detecting objects, the sensors “are not so good for monitoring surfaces,” he added.

Dr. Kristian Döscher, Head of Hella’s Global Marketing for Original Equipment, pointed out that an IDD application can be connected to the existing wiring harness in a vehicle.

“IDD will be an appealing technology to OEMs. But it will also appeal to vehicle sharing and car rental companies because they have frequent driver changes,” said Döscher. “Whenever a vehicle is damaged, it’s important to know when it occurred.”

GKN spins a new compact AWD disconnect system for small SUVs

GKN Driveline is claiming a “world first” for its new compact disconnect system for all-wheel drives (AWD) that can be incorporated into the powertrains of A, B and C-segment vehicles.

The campaign to reduce vehicle fuel consumption involves all aspects of vehicle design but it can be complicated by market trends. The increasing international popularity of small AWD SUVs brings particular challenges but GKN engineers claim their new system can alleviate the problems, with fuel consumption during cruise reduced by up to 4%, and CO2 emissions also lowered.

The entire system including software was developed in-house, said Rob Rickell, Senior Vice President of Engineering. It replaces the usual standard power transfer unit (PTU) with a monobloc housing that also fully integrates the propshaft’s CV joint. A dedicated driveline control unit continuously monitors vehicle dynamics and environmental conditions.

The PTU is linked to the vehicle’s final drive differential and contains a fast-disconnect capability and a braking system to stop the AWD system upstream of the unit’s hypoid gears. An electro-mechanically-actuated clutch located on the rear axle biases drive torque and disengages the AWD system downstream of the hypoid gears in low-load cruise conditions. The clutch system is a development of that used in the Range Rover Evoque.

Connection and disengagement of the disconnect system responds on demand to driver inputs and road conditions, with NVH levels improved as a consequence. AWD reconnection can be established in 300 ms, according to company engineers. When AWD is engaged, an active torque-biasing system looks after distribution to front or rear of the vehicle, and torque vectoring is used between the vehicle’s rear wheels.

Rickell emphasized that the same hardware can support models built off a common platform but with different performance requirements. The software can be fine-tuned to create specific brand characteristics, he said.

GKN’s compact disconnect solution promises to make an important efficiency contribution, though the general technology is not novel. For example Jeep’s 2014 Cherokee, based on a Fiat-Chrysler FWD architecture instead of a traditional rear-drive configuration, offers rear-axle disengagement when 4×4 capability is unnecessary.

The Cherokee uses American Axle & Manufacturing’s EcoTrac rear axle disconnect system, itself claimed as a “first” for a midsize SUV. [See Automotive Engineering cover story June 3, 2014: http://www.nxtbook.com/nxtbooks/sae/14AUTP06/index.php]. Featured on each of the Jeep’s three Active Drive systems available for the Cherokee, a wet clutch in the rear drive module automatically senses input torque and engages AWD when required.

According to Rickell, GKN Driveline is the only supplier able to develop and supply such a tightly integrated AWD system, which he claimed is the lightest, most compact and capable of any available.

Chrysler optimizes process for steel selection, placement

Chrysler’s traditional approach to vehicle development has taken a detour as engineers recently started using new computer tools and an advanced engineering process as a means of designing safer, lighter automobiles.

“The old version was you’d design the major subassemblies first and then integrate those subassemblies into a total vehicle structure. In many cases, we’re able to get the same end results, but we can now refine a design to a level that we previously weren’t able to do,” said Thomas Seel, Chrysler’s Manager of Component Integration, Knowledge Based Engineering.

Using what is referred to as “bio-mimetic topology optimization” combined with a refined engineering process, engineers can determine which body-in-white zones have the highest strain. The process highlights the prime location for the various critical-load paths on the vehicle.

“Taking a holistic approach to body-in-white is similar to concurrent engineering because unlike an iterative solution, the engineering process is looking at all the load cases—durability, stiffness, and safety—simultaneously,” said Seel.

Advanced high-strength steels (AHSS) are part of the optimized body structure design process. “Drivers for AHSS include safety, mass control, fuel economy, and affordability,” said David Jeanes, Senior Vice President of Market Development for the American Iron and Steel Institute (AISI), whose member companies represent more than 75% of North America’s steel capacity.

By using this proprietary process, Chrysler engineers select steels according to what is needed. “It allows you to peel away weight where you don’t need it,” said Bill Grabowski, Director of Body Core Engineering at Chrysler. Chrysler officials predict that as much as 120 lb (54 kg) could be shed from the body-in-white—essentially equating to a 1% fuel-economy improvement—by optimizing the vehicle’s skeleton.

“If you know the load requirements of the vehicle, such as torsional rigidity, side impacts, and roof strength, then these new computer tools can work with the available load paths to identify what’s strong and what’s weak so that engineers can design a better structure,” said Ron Krupitzer, Vice President of AISI’s Automotive Applications Committee.

Load optimization also occurs at the component level. For instance, an advanced design of a future production vehicle—by virtue of AHSS topology optimization—resulted in a weight savings of 1.12 lb (0.51 kg) on a front shock tower. “We predict an up to 13% weight reduction of the entire body structure, resulting in improved fuel economy because of the bio-mimetic topology tools and the engineering process,” said Grabowski, who was making a comparison to vehicles using conventional high-strength steels and design methods.

Current Chrysler vehicles use approximately 20 to 30% high-strength steel in the bodies, “but in the next three to five years, Chrysler vehicles will apply upward of 60% high-strength steels,” Grabowski said, noting that as early as 2010 Chrysler vehicle bodies could be made of 29% high-strength low-alloy steel, 30% AHSS, and 41% mild steel.

AISI, Chrysler, Mercedes Group Research, and MB Tech (Mercedes-Benz Technologies) all contributed to developing the new topology tools and the engineering process, which helps “accelerate the use of new AHSS to optimize body structures,” said Jeanes.

Although Chrysler currently is using the topology-modeling tools and engineering process for body structures, the body-in-white is only the first application. “The tools and process are not limited to just the body structure,” Seel said, declining to elaborate.

Tech Mahindra to collaborate with Wichita State University in the areas of aerospace engineering, automotive testing

Country’s fifth largest software services firm Tech Mahindra has inked a pact with US-based Wichita State University (WSU) to collaborate in the areas of aerospace engineering, certification, information technology and automotive testing.

Tech Mahindra will collaborate with WSU and its National Institute for Aviation Research (NIAR), the largest academic aviation R&D institution in the US, on multiple areas of engineering including composites, advanced materials and structural testing, it said in a statement.

“I strongly believe that this synergy can help reach the next level of solution offerings to our marquee customers addressing their custom needs and industry specific requirements in the areas of certification and testing,” Tech Mahindra Head of Americas (Aerospace and Defence) Krishna Balasubramaniam said.

The Indian IT firm plans to invest in equipping the engineering talent available in the region to enhance their employment opportunities in the Wichita aerospace community.

“This investment will enable Tech Mahindra to provide end-to-end solutions from design, to testing and certification for global aerospace and automotive customers and prospects in the region,” it said.

Apart from creating a local pool of trained aerospace, IT and automotive engineers, the partnership will also facilitate cooperative initiatives in the area of innovation and R&D projects, including possible involvement with WSU’s Innovation Campus.

The partnership will also enable WSU to further expand its footprint into the automotive industry and provide its students an opportunity to develop industry skills through involvement in Tech Mahindra’s research and testing projects.

“WSU will get firmly connected to the automotive and industrial sector, allowing students to gain real-world engineering skills in a unique sector,” WSU VP (Research and Technology Transfer) John Tomblin said.