Wednesday, May 27, 2015

Research team explores a novel way to fabricate preforms for composites.

Michael Keefe, Zhenzhen Quan and Tsu-Wei Chou are part of an international team of researchers that is examining the feasibility of using additive manufacturing to produce 3D preforms.
In the 1967 movie The Graduate, young Benjamin Braddock gets a now-famous one-word piece of advice about the future from a family friend: plastics.
At about the same time, the University of Delaware's Tsu-Wei Chou, then a graduate student at Stanford University, sought advice from his adviser about future research directions. His answer contained two words: .
Chou followed his adviser's suggestion and went on to become a pioneer in advanced composites, working over the years with a wide variety of materials and processes. Almost five decades later, he is still on the hunt for innovations that will make more affordable, reliable and functional.
His latest breakthrough builds on work he did in the 1980s and '90s on textile structural composites. This technology applies braiding, weaving, knitting and stitching techniques to produce 3D reinforcements, which are then combined with a binder, or matrix, to make complex shapes.
While textile structural composites offer such advantages as structural integrity, damage tolerance and cost-effectiveness, some fundamental technological barriers remain in their manufacture, which can lead to inconsistencies in performance.
Now Chou, Pierre S. du Pont Chair of Engineering at the University of Delaware, is part of an international team of researchers that is examining the feasibility of using to produce 3D preforms.
Their work is documented in a paper published in the web version of Materials Today on May 23.
Additive manufacturing, also broadly known as "rapid prototyping" and "freeform fabrication," is a process in which an object is built up layer by layer from a computerized model. The technique enables direct fabrication of complex-shaped objects without tooling and machining, and it eliminates the need to join a number of single parts into a single complex one.
In traditional processes, complex parts are usually built by assembling separate simple parts, which can lead to premature structural failure at material joints.
Another advantage of this technology is that material composition can be changed at specified locations within a part at the processing stage, enabling various functions and graded properties to be incorporated directly during manufacturing.
The process also shortens lead time and makes small-lot-size customization—even a run of just a single part—economical.
Finally, in additive manufacturing, the material is placed just where it is needed, and the residual material can often be readily recycled or reused, reducing material waste.
"All of these features make additive manufacturing an attractive option for composite materials development," Chou says.
The paper reviews the state of the art within the scope of composites development and discusses challenges facing the broad adoption of additive manufacturing for directionally reinforced composites processing.
Those challenges include the need for new CAD tools and engineering standards, difficulties in process monitoring, and limitations in part size, printing accuracy, layer thickness, and surface smoothness.
Despite these limitations, Chou sees great potential in additive manufacturing of fiber-reinforced preforms, which, he says, are especially desirable for composite parts in aerospace and biomedical applications.
More information: "Additive manufacturing of multi-directional preforms for composites: opportunities and challenges," Materials Today, Available online 23 May 2015, ISSN 1369-7021,

Thursday, January 14, 2010

Next-generation autos go for global connectivity.

Bryan Nesbitt, Cadillac General Manager, introduces the new Cadillac XTS Platinum concept vehicle to the media at the General Motors exhibit at the North American International Auto Show in Detroit, Michigan. Touch navigational screens, Internet, communications systems: Automakers are ramping up an array of connectivity gizmos to lure consumers into buying next-generation vehicles.
Touch navigational screens, Internet, communications systems: Automakers are ramping up an array of connectivity gizmos to lure consumers into buying next-generation vehicles.
Some of the whistles and bells on display at the annual North American Internation Auto Show underway in Detroit were purely cosmetic.
GM's Cadillac presented a prototype of its new XTS sedan that sported a dashboard minus buttons or dials. The black screen illuminates once the engine starts and the door handles light up for a few seconds when the
But most of the innovations put a premium on connectivity.
Paul Haelterman, vice president of research firm CSM Worldwide, predicted that five years from now 45 percent of the new vehicles sold in North America would be connected to the Internet, and nearly all of the luxury models.
"Having the car connected with the exterior world is a necessity," said Henning Schlieker, a technology marketing executive at BMW North America, told AFP.
The German luxury
already has begun to equip all its BMW 5 Series, 6 Series and 7 Series cars sold in the United States with BMW Assist, a feature launched a year and a half ago.
The BMW Assist allows drivers to locate gasoline stations and their current prices, check weather forecasts and traffic conditions, access navigational tools such as
Maps and Mapquest, and keep tabs on financial data.
The Cadillac XTS offers two separate back-seat screens, each outfitted with its own Internet connection and DVD reader.
Ford is launching its MyFord Touch system, which will be introduced first in the upscale Lincoln nameplate under the name "MyLincoln Touch" and then integrated into the Ford Focus in 2012.
With the Ford system, drivers will be able to listen to their favorite websites, including an audio version of the fast-streaming Twitter microblogs and music from the Pandora Radio.
The screens on next-generation vehicles function with touch commands when the vehicle is stopped, allowing drivers to change their selections without interfering with their driving.
Automakers assure that these new functions and Web access in vehicles pose no danger.
"We're in the business of safe transportation," Allan Mulally, the chief executive of Ford, said Tuesday at the Detroit show.
"You're best driving if you keep your eyes on the road and your hands on the wheel," he added.
To avoid distracting the driver, the interactive functions are all operated by voice or by buttons located at the steering wheel.
At BMW the screens close to the driver only change when they are changed intentionally and there are no animated graphics or advertising windows that could divert attention, Schlieker said.
But in case of an accident, BMW also offers emergency system ACN, or automatic collision notification, which alerts authorities and emergency aid workers, pinpoints the location of the vehicle and provides an assessment of the gravity of the incident.
The auto show, which opened Monday in Detroit, the home of the Big Three US automakers General Motors, Ford and Chrysler, is scheduled to close January 24.

'Greenroads' Rates Sustainable Road Projects.

Greenroads evaluates a road's environmental and social impacts. It assigns points for such things as using local or recycled materials, managing runoff and providing wildlife corridors. (Credit: University of Washington)
Source: ScienceDaily
ScienceDaily (Jan. 13, 2010) — Road construction is a more than $80 billion annual industry in the United States. Yet nothing comparable to the LEED rating system for buildings, or the Energy Star system for appliances, exists for highways and roads.
University of Washington researchers and global engineering firm CH2M Hill have unveiled Greenroads, a rating system for sustainable road design and construction. Environmental, economic and social impacts are included. The system outlines minimum requirements to qualify as a green roadway, including a noise mitigation plan, storm-water management plan and waste management plan. It also allows up to 118 points for voluntary actions such as minimizing light pollution, using recycled materials, incorporating quiet pavement and accommodating non-motorized transportation.
"The LEED [Leadership in Energy and Environmental Design] system has been really successful and has achieved a lot," said lead author Steve Muench, a UW assistant professor of civil and environmental engineering. "Roads are a big chunk of the construction industry that has an opportunity to participate more fully in sustainability practices. I think there's a lot of opportunity there."
The first complete version of Greenroads is now available at Muench presented the project January 13 at the Transportation Research Board's annual meeting in Washington, D.C.
The rating system was developed during the past three years by the UW Greenroads team and collaborators at CH2M Hill.
Greenroads' aims are threefold: to recognize companies already using sustainable methods; to provide a catalog of ideas for greener practices; and to offer an incentive for agencies and companies to build more environmentally friendly roads. The system can be used either for new road projects or for upgrades on existing roads.
"This helps our industry become more sustainable and shows the public that we can deliver sustainable roadways," said Tim Bevan, west region technology manager at CH2M Hill. "To some, it has not been perceived to be that important, but more and more we're finding the public is concerned about the environmental impacts of roadways."
A number of government agencies have already expressed interest in the project, including the Oregon Department of Transportation and the British Columbia Ministry of Transportation and Highways.
Managers can have their projects rated for a fee by contacting the Greenroads team. Right now, limited staff means only some projects can be rated. In the long term, the team hopes to allow qualified third-party consultants to do the ratings.
"We've had a lot of positive response," Muench said. "It's quickly becoming something that needs to be more than a research project."
Greenroads originated in 2007 when Martina Söderlund, a graduate student from Sweden, came to the UW through the Valle Scholarship and Scandinavian Exchange Program.
"She was interested in sustainability and I was interested in roads, so we put our heads together and came up with this," said Muench, who was Söderlund's adviser for her master's thesis.
Now that the thesis has evolved into a complete document, the team is hoping to get feedback on the system's ease of use, choice of credits and the point value assigned to each credit.
"This first version is just a starting point. We'd like to know what industry thinks of the system and get their help in developing it further," Muench said.
Research funding was provided by Transportation Northwest at the UW, the State Pavement Technology Consortium, Western Federal Lands Highway Division and the Oregon Department of Transportation. CH2M Hill contributed staff time to the project.
Story Source:
Adapted from materials provided by
University of Washington, via EurekAlert!, a service of AAAS.

Tuesday, January 12, 2010

Honda beats Toyota to a sporty hybrid for US market.

The new Honda CR-Z is on display at the North American International Auto Show January 11 in Detroit, Michigan. Honda unveiled a sporty new hybrid vehicle Monday that will land in US showrooms this summer -- at least two years ahead of a similar prototype introduced by rival Toyota.
Honda unveiled a sporty new hybrid vehicle that will land in US showrooms this summer -- at least two years ahead of a similar prototype introduced by rival Toyota.
"Now, I know you've heard from others with plans to offer up a product in this new segment," said American Honda Motor vice president John Mendel.
"But this is a real car coming to you in just a few months."
The Honda CR-Z is a sporty two-seater designed to evoke memories of the Japanese automaker's popular but now defunct CR-X.
It will build on Honda's existing US lineup of hybrid vehicles -- the Civic and the Insight. The automaker also announced plans to add hybrids to its luxury Acura brand. Related article: Optimism at

"CR-Z is an altogether new vision -- a renaissance if you will -- for a car of the future," Mendel said.
"The CR-Z was developed for a more discerning customer who is seeking a unique combination of forward-looking style, fun-to-drive spirit, advanced safety and
Toyota, which is expected to introduce eight new hybrids in the next few years, introduced a prototype of a two-seater hybrid with somewhat less of a sporty style.
The FT-CH concept car is aimed at Toyota's strategy "to offer a wider variety of conventional hybrid choices to its customers," as it begins to introduce plug-in hybrids and battery-powered vehicles in global markets, the company said.
It is expected to go on sale in 2012.
Honda was the first automaker to introduce a mass market hybrid in 1999 with the hatch-back two door Insight, revived last year as a roomier four-door.
But Toyota soon dominated the hybrid market with its popular dedicated model, the Prius.
Honda said it is continuing to forge ahead in developing alternative powertrains and plans to introduce an all-electric commuter car to the US market in the coming years.
"We continue to believe that a
electric vehicle is the ultimate solution to reducing CO2 (carbon dioxide) emissions," said Takanobu Ito, president and chief executive officer of .
"A fuel cell car is a full electric vehicle, but rather than use electricity from the grid, a fuel cell vehicle generates electricity on board and refills more quickly."
While the technology already exists to build fuel cell vehicles, Ito said the manufacturing costs must come down and the infrastructure to support hydrogen fueling must be developed.
"But make no mistake. As a vehicle, the Honda FCX Clarity is ready now," he said.
"Further, Honda is unique in making long-term investments to develop the refueling infrastructure for alternative fuel vehicles."
The automaker will begin operating its next-generation solar hydrogen station at its Los Angeles research station later this month.
Under the system, which could fit on the roof of a typical US home, solar panels help transform water into hydrogen fuel.
The latest generation eliminates the need for a costly compressor and also allows the system to be small enough to fit in a standard garage.
But Ito said expanding the use of hybrid vehicles is the "most important" near-term approach.
"To increase the opportunity for more customers to choose a hybrid we must be able to meet different needs with family, luxury and sporty hybrid vehicles," he said.
"We will apply hybrid systems which are compact, lightweight and affordable to a wider range of products in the near future."

Friday, July 17, 2009

Hydrogen Technology Steams Ahead

ScienceDaily (July 17, 2009) — Could the cars and laptops of the future be fuelled by old chip fat? Engineers at the University of Leeds believe so, and are developing an energy efficient, environmentally-friendly hydrogen production system. The system enables hydrogen to be extracted from waste materials, such as vegetable oil and the glycerol by-product of bio-diesel. The aim is to create the high purity hydrogen-based fuel necessary not only for large-scale power production, but also for smaller portable fuel cells.
Dr Valerie Dupont from the School of Process, Environmental and Materials Engineering (SPEME) says: “I can foresee a time when the processes we are investigating could help ensure that hydrogen is a mainstream fuel.
“We are investigating the feasibility of creating a uniquely energy efficient method of hydrogen production which uses air rather than burners to heat the raw product. Our current research will improve the sustainability of this process and reduce its carbon emissions.”
A grant of over £400k has been awarded to the University by the Engineering and Physical Sciences Research Council (EPSRC) within a consortium of 12 institutions known as SUPERGEN Sustainable Hydrogen Delivery.
Hydrogen is widely considered to be a potential replacement for fossil fuels, but it is costly to extract. There are also often high levels of greenhouse gases emitted during conventional methods of production.
The system being developed at Leeds – known as Unmixed and Sorption-Enhanced Steam Reforming - mixes waste products with steam to release hydrogen and is potentially cheaper, cleaner and more energy efficient.
A hydrocarbon-based fuel from plant or waste sources is mixed with steam in a catalytic reactor, generating hydrogen and carbon dioxide along with excess water. The water is then easily condensed by cooling and the carbon dioxide is removed in-situ by a solid sorbent material.
Dr Dupont says: “It’s becoming increasingly necessary for scientists devising new technologies to limit the amount of carbon dioxide they release. This project takes us one step closer to these goals – once we have technologies that enable us to produce hydrogen sustainably, the infrastructure to support its use will grow.”
“We firmly believe that these advanced steam reforming processes have great potential for helping to build the hydrogen economy. Our primary focus now is to ensure the materials we rely on - both to catalyse the desired reaction and to capture the carbon dioxide – can be used over and over again without losing their efficacy.”
Adapted from materials provided by University of Leeds.

Wednesday, July 15, 2009

Blind Can Take Wheel With Newly Designed Vehicle

ScienceDaily (July 15, 2009) — A student team in the Virginia Tech College of Engineering is providing the blind with an opportunity many never thought possible: The opportunity to drive.
A retrofitted four-wheel dirt buggy developed by the Blind Driver Challenge team ( from Virginia Tech's Robotics and Mechanisms Laboratory uses laser range finders, an instant voice command interface and a host of other innovative, cutting-edge technology to guide blind drivers as they steer, brake, and accelerate. Although in the early testing stage, the National Federation of the Blind -- which spurred the project -- considers the vehicle a major breakthrough for independent living of the visually impaired.
"It was great!" said Wes Majerus, of Baltimore, the first blind person to drive the buggy on a closed course at the Virginia Tech campus this summer. Majerus is an access technology specialist with the National Federation of the Blind's Jernigan Institute in Baltimore, a research and training institute dedicated to developing technologies and services to help the blind achieve independence.
Majerus called his drive a liberating experience, adding that he drove before on Nebraska farm roads with his father as a guide in the passenger seat.
Sitting inside the vehicle, a blind driver can turn the steering wheel, stop and accelerate by following data from a computing unit that uses sensory information from the laser range finder serving as the 'eyes' of the driver, in addition to a combination of voice commands and a vibrating vest as guides. A member of the Virginia Tech student team sat next to Majerus in the passenger seat to monitor the system's software operations.
"It's a great first step," Majerus added. "As far as the differences between human instructions and those given by the voice in the Blind Driver Challenge car, the car's instructions are very precise. You use the technology to act on the environment -- the driving course -- in a very orderly manner. In some cases, the human passenger will be vague, "turn left" -- does that mean just a small turn to the left, or are we going for large amounts of turn?"
Also driving the vehicle was Mark Riccobono, also of Baltimore, the executive director of the Jernigan Institute, who also is blind. He called his test drive historic. "This is sort of our going to the moon project," he said
In 2004 Jernigan Institute challenged university research teams to develop a vehicle that would one day allow the blind to drive. Virginia Tech was the only university in the nation to accept the nonprofit's call two years later, said Dennis Hong, director of the Robotics and Mechanisms Laboratory, part of the Virginia Tech mechanical engineering department. The National Federation of the Blind provided a $3,000 grant to launch the project.
"I thought it would be a very rewarding project, helping the blind," said Hong, the current faculty adviser on the project. "We are not only excited about the vehicle itself, but more than that, we are excited about the potential of the many spin-off technologies from this project that can be used for helping the blind in so many ways."
The team will bring the Blind Driver Challenge vehicle to the National Federation of the Blind's Youth Slam summer camp event held July 26 through Aug. 1 in College Park, Md. There, the team hopes to have teenagers who would be obtaining their driver's licenses, but cannot because of their blindness, drive the buggy.
Youth participants also are expected to remote control drive miniature cars. Additionally, the car is expected to ride in a National Federation of the Blind-sponsored parade in Washington D.C.
"I most look forward to learning as much as I can from these bright young students," said Greg Jannaman, who led the Virginia Tech student team in his senior year and graduated in May with a bachelor's degree in mechanical engineering. "Blind students from across the nation apply to be selected to attend this summer camp. While we are there to provide an educational experience for them, I can only imagine the invaluable feedback and fresh new ideas that they will provide in return."
Jannaman is excited about the vehicle's success. "There wasn't a moment's hesitation with any of our blind drivers, whereas blind-folded sighted drivers weren't as quick to let go of their preconceptions," said Jannaman of Hendersonville, Tenn. "The blind drivers actually performed better than their sighted counterparts. An overwhelming sense of accomplishment overcame me as I simply rode along while Wes and Mark successfully navigated the driving course without my assistance."
Early models of the Blind Driver Challenge vehicle relied more on technologies for fully autonomous vehicles, previously developed by Virginia Tech mechanical engineering students as part of the DARPA Urban Challenge ( The student team redesigned the vehicle so that the blind motorist has complete control of the driving process, as any sighted driver would.
This change in approach led to new challenges, including how to effectively convey the high bandwidth of information from the laser sensors scanning the vehicle's surrounding environment to the driver fast enough and accurate enough to allow safe driving. As a result, the team developed non-visual interface technologies, including a vibrating vest for feedback on speed, a click counter steering wheel with audio cues, spoken commands for directional feedback, and a unique tactile map interface that utilizes compressed air to provide information about the road and obstacles surrounding the vehicle.
Riccobono knows of mock ups and non-working "blind driver car" set-ups from the past, but says this is the first working vehicle to put the blind and visually impaired in control of the steering wheel. "Blind people have brains, the capacity to make decisions," he said. "Blind people want to live independent lives, why would they not want to drive?"
Even once the technology is perfected, laws now barring the blind from driving and public perception must be changed, Riccobono said. "This is the piece that we know will be the most difficult," said Riccobono, adding that the car must be near-perfected before the National Federation of the Blind can truly push the car to law-makers and the general public. He said this effort will take millions of dollars in development.
The 2009-10 student team already is planning major changes to the technology, including replacing the dirt buggy vehicle with a fully electric car commonly used by traffic officers in downtown city centers. The all-electric vehicle would reduce the vibration which can cause problems to the laser sensor, and it will provide clean electric power for the computing units and that is better for the environment.
Hong is a National Science Foundation CAREER Award recipient. He received his bachelor's degree in mechanical engineering from the University of Wisconsin-Madison in 1994, and his master's and doctoral degrees in mechanical engineering from Purdue University in 1999 and 2002, respectively.
Adapted from materials provided by Virginia Tech.