New Material For Aircraft Wings Could Save Billions

Source:

http://www.sciencedaily.com/releases/2007/09/070926094727.htm

Science Daily — Building aircraft wings with a special aluminium fibre combination makes them nearly immune to metal fatigue. The application of this technology, partly developed at Delft University of Technology, will lead to substantial savings.

The unusual qualities of this special material (called CentrAl, an abbreviation of Central Reinforced Aluminium) can make a significant contribution to the development of truly energy-efficient, 'green' aircraft. Lower fuel consumption and reduction of maintenance costs could lead to worldwide savings as high as $100 billion.
Fatigue is a phenomenon that affects materials after long-term exposure to cyclic loading. As a result of varying loads, fractures eventually occur. The new, high-quality CentrAl aluminium constructions are stronger than the carbon fibre reinforced plastic (CFRP) constructions that have recently been used in aircraft wings such as the Boeing 787. By using CentrAl wing constructions, the weight can be reduced by another 20 per cent compared to CFRP constructions. Furthermore, using CentrAl results in considerably lower manufacturing and maintenance costs.
The CentrAl concept comprises a central layer of fibre metal laminate (FML), sandwiched between one or more thick layers of high-quality aluminium. This creates a robust construction material which is not only exceptionally strong, but also insensitive to fatigue. The CentrAl technique allows for simple repairs to be carried out immediately, as is the case in aluminium constructions, -- but not the case when using CFRP constructions.
This patented new concept is one of the results of an intensive collaboration between the company GTM Advanced Structures, founded in The Hague in 2004 and specialising in new aircraft materials and constructions, the American aluminium company Alcoa, and the Faculty of Aerospace Engineering of Delft University of Technology.
During a conference in Delft (Conference on Damage Tolerance of Aircraft Structures: 25-28 September 2007), GTM and Alcoa have presented the new concept to international experts in the field of metal fatigue and damage sensitivity of aircraft constructions. The US Air Force, Alcoa and GTM will also shed new light on the fact that the new CentrAl materials create possibilities for so-called 'Carefree structures'.
These are aircraft constructions that are less sensitive to damage caused, for example, by fatigue, hail storms, other weather phenomena, trucks that collide with the aircraft and corrosion. Carefree aircraft constructions will be characterised by significantly reduced maintenance costs.
Note: This story has been adapted from a news release issued by Delft University of Technology.

Fausto Intilla

www.oloscience.com

Bridge Strengthening Research

Source:

http://www.sciencedaily.com/releases/2007/09/070914163132.htm

Science Daily — These days, a drive across a bridge is not always a pleasure cruise. Mindful of the war on terrorism, it can often be a cautious experience.

In one scenario, someone sets off a series of bombs to weaken the cables and the key structural connections of a major city bridge, all during rush hour. Not easy to do, but now thinkable. This summer, the possibility of sabotage was quickly examined—then dismissed—when the I35W bridge in Minneapolis tragically collapsed into the Mississippi River.
As authorities monitor and stand guard over bridges, the Homeland Security Science & Technology Directorate is looking to scientists and engineers for the security technologies of tomorrow. What if, for instance, we could one day not only guard bridges but fortify them? Like Superman’s blue suit, what if the cables and connections on bridges could be shielded with protective sleeves or covers, making them nearly impossible for the villains to penetrate?
This is the goal of the Directorate's bridge-strengthening research. Through a partnership with the U.S. Army Corps of Engineers’ Engineer Research and Development Center, the Directorate’s Infrastructure and Geophysical Division is testing current bridge designs and investigating advances in steel and reinforced concrete to explore whether such shields could work.
The first step is to determine which bridges and materials are most vulnerable, says Stanley Woodson, who oversees the project at the Center’s Geotech and Structures Lab. A major focus, he says, are the cables and the support columns—or towers—that are used in the cable-stayed design of bridges. Unlike the cables of a suspension bridge, which are attached from tower to tower, the cables in a cable-stayed bridge are connected directly to accessible points along the horizontal bridge deck.
"In controlled experiments, Woodson’s team has been re-creating the forces holding up these bridges and blowing up samples of their cables using various kinds of explosives," say Dr. Mary Ellen Hynes, director of the research. "They then use sophisticated software to analyze the impact and results."
“We tension the cables just like a real bridge,” Woodson explains. “We want to see just how they’d react in an actual terrorist event.”
The next step will be more complicated, says Woodson: Determining what material would suffice for another layer of protection, and what form it should take. “We’re looking at the practical as well as the innovative,” he says, recognizing the potential for high costs.
By the end of 2008, Woodson and his team will be imitating concrete bridge towers and subjecting them to the same explosive testing.
Note: This story has been adapted from a news release issued by Department of Homeland Security.

Fausto Intilla

www.oloscience.com

Skyray 48 Takes Flight

Source:

http://www.sciencedaily.com/releases/2007/09/070919174711.htm

Science Daily — Calm excitement filled the ground control station. Engineers stared intently at their computer screens as the pilot, sitting next to them, flexed his fingers on the controls. Ground crew tending the aircraft finished putting away their equipment. Preparations for the first flight of the unmanned X-48B Blended Wing Body research aircraft were complete.

Years of research, design, construction, wind tunnel and ground tests coalesced into this one moment of time.
Radios crackled. "Tower, Skyray 48 in position, lakebed runway 23, request clearance for takeoff..."
"Skyray 48 roger, main base winds 220 at 6, report airborne, lakebed 23..."
"Wilco"
"Five, four, three, two, one, brakes..."
Quickly, the manta ray-shaped aircraft rolled down the dry lakebed runway trailing a plume of dust as it picked up speed, its three small jet engines whining.
With an excitement that only comes with an aircraft's first flight, the triangular red, white and blue X-48B leapt into the air, obviously wanting to fly.
"Skyray 48's airborne," Boeing pilot Norm Howell called, matter-of-factly. And with that, years of toil blossomed into the sweet fruit of success on July 20, 2007 at NASA's Dryden Flight Research Center on Edwards AFB, Calif.
One of the latest cutting-edge experimental aircraft, or X-Planes, the X-48B BWB is a collaborative effort of the Boeing Co., NASA's Fundamental Aeronautics Program, and the Air Force Research Laboratory. The 21-foot wingspan, 500-pound, remotely piloted plane is designed to demonstrate the viability of the blended wing shape. And demonstrate it has.
After completion of six flights, the X-48B team began a four-week maintenance and modification period during which removable leading edges with extended slats are being replaced with slatless leading edges in order to mimic a slats-retracted configuration. The change requires a software update to the flight control software. In addition, the team is removing and replacing all of the aircraft's flight control actuators for maintenance purposes.
NASA is interested in the potential benefits of the aircraft - increased volume for carrying capacity, efficient aerodynamics for reduced fuel burn, and, possibly, significant reductions in noise due to propulsion integration options. In these initial flights, the principal focus is to validate prior research on the aerodynamic performance and controllability of the shape, including comparisons of flight test data with the extensive database gathered in the wind tunnels at NASA's Langley Research Center in Virginia.
The Subsonic Fixed-Wing Project, part of NASA's Fundamental Aeronautics Program, has long supported the development of the blended wing body concept. It has participated in numerous collaborations with Boeing, as well as several wind tunnel tests for different speed regimes. The team is focused on researching the low-speed characteristics of the design and expanding its flight envelope beyond the limits of current capabilities.
In addition to hosting the X-48B flight test and research activities, NASA Dryden is providing engineering and technical support -- expertise garnered from years of operating cutting-edge air vehicles. NASA assists with the hardware and software validation and verification process, the integration and testing of the aircraft systems, and the pilot's ground control station. NASA's range group provides critical telemetry and command and control communications during the flight, while the flight operations group provides a T-34 chase aircraft and essential flight scheduling. Photo and video support complete the effort.
The composite-skinned, 8.5 percent scale vehicle can to fly up to 10,000 feet and 120 knots in its low-speed configuration. The aircraft is flown remotely from a ground control station by a pilot using conventional aircraft controls and instrumentation, while looking at a monitor fed by a forward-looking camera on the aircraft.
Up to 25 flights are planned to gather data in these low-speed flight regimes. Then, the X-48B may be used to test the aircraft's low-noise and handling characteristics at transonic speeds.
Two X-48B research vehicles were built by Cranfield Aerospace Ltd., in England, in accordance with Boeing specifications. The vehicle that flew on July 20, known as Ship 2, was also used for ground and taxi testing. Ship 1, a duplicate, was used for the wind tunnel tests. Ship 1 is available for use as a backup during the flight test program.
So far, so good as the Skyray 48 team works through the late summer heat of the Mojave Desert as they continue blazing a trail with this futuristic aircraft design.
Note: This story has been adapted from a news release issued by National Aeronautics And Space Administration.

Fausto Intilla

www.oloscience.com

Safer Car Controls

Source:

http://www.sciencedaily.com/releases/2007/09/070909215312.htm

Science Daily — The number of electronic components in cars is growing rapidly. To ensure that vehicle electronics will work properly in future despite the overabundance of software and its increasing complexity, researchers are remodeling it and making it even safer.

The sight of a shiny new car suggests streamlined high-tech devices. But appearances are deceptive. Under the hood, all is confusion. Around 100 microprocessors control auxiliary functions such as ABS, ESP or the headlight that can shine around corners. Almost as many control units send their commands to fuel injection systems, airbags and other functional modules.
Components from numerous manufacturers are scattered throughout the car body. Vehicle development engineers attempting to unite all the different systems into a working entity face a truly Herculean task, for each control unit carries its own software. Experts expect the volume of software in new cars to continue to increase by as much as 300 percent in the next four years.
The Fraunhofer Institute for Software and Systems Engineering ISST in Berlin has joined the international development initiative AUTOSAR (Automotive Open System Architecture) on behalf of the BMW Group. All the well-known car manufacturers and suppliers are members of the partnership. The goal of AUTOSAR is to pare down the ballast of in-car software and make it easier to handle.
The idea behind it is that vehicle functions will first be defined and linked together independently of their specific platforms. Only at the next stage are these functions to be assigned to the vehicle’s existing control units. After this the infrastructural software, likewise standardized, needs to be “fine-tuned”. However, the actual information processing takes place at a higher level, on the AUTOSAR Virtual Functional Bus. This approach simplifies matters tremendously and reveals a way of structuring the growing confusion of software.
“At long last, AUTOSAR gives software integrators in the automotive industry something that developers in other sectors, in the form of standardized development libraries, have had at their fingertips for decades,” says Markus Hardt, head of the department for reliable technical systems at the ISST. But before AUTOSAR can take to the road in tomorrow’s cars, it has to be tested to ensure it functions in a stable manner.
To enable this, Markus Hardt and his colleagues are developing the “aXBench”, a test platform that simulates the AUTOSAR architecture’s mode of operation and suggests an optimal distribution of functions. The “aXBench” enables the scientists to imitate and evaluate the correct functioning of control units, the swift transmission of data between the middleware and the receiver, and even true-to-life details such as hardware and software response times.
Note: This story has been adapted from a news release issued by Fraunhofer-Gesellschaft.

Fausto Intilla

www.oloscience.com