PREDICTING A FRACTURE

Don’t wait for the break. An assistant professor is now at work on mathematical models that would help engineers predict fractures within materials before they happen.

Blaise Bourdin, an assistant mathematics professor at Louisiana State University in Baton Rouge, is also an expert in fracture mechanics, the study of brittle materials and of predicting the failure of a structure containing a crack.

He and two colleagues are now at work on 3-D mathematical models that forecast the potential location and path of a crack in brittle materials like glass, concrete, and steel. Collaborators are mathematicians G. Francfort of Université Paris Nord and J.J. Marigo of Université Pierre et Marie Curie in France.

Researchers are at work on computer models that will
simulate where a crack will appear in a particular
material. A 3-D simulation of a brittle, reinforced cylinder
(above) attempts to demonstrate where a crack to
the cylinder will appear.

The researchers seek methods to simulate and model fracture mechanics so engineers can predict failure before it happens, Bourdin said.

“Most methods in classical fracture mechanics assume that you know the solution before you can solve the problem,” Bourdin said. “You assume that you have a priori knowledge of potential cracks and then solve for those cracks.”

Bourdin and his collaborators’ models begin with mathematical data for the device in question, like a cylinder or a beam. The engineer would then apply knowledge of the material, how it behaves under stress, and other factors, like temperature and load, to predict where potential cracks might form.

The models result in enormous amounts of data, sometimes up to 15 gigabytes for one simulation. Bourdin’s team relies on Teragrid, a nationwide supercomputing network, to store and manipulate the data.

To view the data in animation form, the researchers are using EnSight visualization software from CEI Inc. of Apex, N.C. The researchers also use Cubit, developed by Sandia National Laboratories of Albuquerque, N.M., to mesh the model for analysis purposes.

“As a mathematician, I’m mostly interested in this fracture model because of the challenges posed by its numerical implementation,” Bourdin said. “Of course, it also happens that it’s a good mechanical model and can be used to analyze the potential soundness of materials and systems before they are put into place.”

ACROSS THE UNIVERSITIES

Nearly all countries have research and education networks, which are separate from their commercial telecommunications networks. Problem is, most of these networks are based on a mishmash of different technologies, network protocols, and architecture—a situation that can make connections between networks quite difficult.

The most familiar example of a research network is the National Research and Education Network, which eventually evolved into the Internet. Nearly every country has its own NREN-type network linking universities, research institutions, and computing centers.

The difficulty lies in connecting the different networks to each other and particularly to commercial networks. Now, European researchers are working to weld the technologies, protocols, and system architectures that make up research and education networks to make connection smoother.

They call the project MUPBED, which is short for the project’s mouthful of a name: Multi-Partner European Test Beds for Research Networking.

Researchers with the MUPBED project spent about three years, through the end of 2007, researching and testing ways in which the disparate components of different networks could be seamlessly linked for high-quality, quick communications with very high bandwidth requirements, said Jan Spaeth, project coordinator.

The starting point for the project was to find a simple, fast way for people at various universities in different countries to share information, Spaeth said.

That’s easier said than done. Research networks are usually composed of three levels. At the bottom are the individual campus departments linked via a university network. Each university network is joined to the national network within the institution’s home country. In the EU, the national networks then link to the European network.

“Somebody at a university somewhere in Europe may have to go through several different technologies and network domains before connecting to a colleague at another European university,” Spaeth said. “And then the quality of connection will not allow them to exchange the information they need to.”

MUPBED researchers found that the solution would be to cut vertically through the layers. When a user makes a request for a connection of a particular bandwidth for a specific purpose, an automatic connection would be set up directly between the networks. The networks then communicate directly with each other, essentially cutting out the middlemen.

As part of their research, the MUPBED partners constructed a series of connected test beds across the European networks. They proved their solution was technically feasible, Spaeth said.

It’s now up to the research networks, and later the commercial operators, to decide if and when to invest in the infrastructure, Spaeth added.

MINE MESH

Finite element analysis is going below ground.

Although they are not traditional users of the analysis method, many mining companies have been relying on FEA of late to improve design, planning, and operations at a number of mines around the world, said Joop Nagtegaal, a Dassault Systèmes corporate fellow who has been tracking this use.
Many mining companies now use FEA software that depicts, as above, models of rock mass and mine excavation to compare engineering options.

Paris-based Dassault produces engineering software, including FEA software.

“In the design stage, models—which include rock mass volumes spanning several kilometers around the ore body and to excavations just a few meters across—are used to compare and optimize engineering options,” he said. “Then, as the mine goes into production, large volumes of data from the field are incorporated with the analysis models to allow them to be calibrated to a precision not previously available to the mining industry.”

Many mining companies now use FEA software that depicts, as above, models of rock mass and mine excavation to compare engineering options.

Beck Arndt Engineering of Sydney is now using Abaqus from Simulia, owned by Dassault, for mining applications.

Debswana’s Jwaneng Mine in Botswana, Africa; the Newcrest Mining Ridgeway Deeps Project in New South Wales, Australia, and the Rio Tinto Group’s Argyle Diamond mine in Western Australia are also using Abaqus FEA analysis for simulation-aided mining engineering, Nagtegaal said.

SUPERCOMPUTER SEEKS SOFTWARE

The newest breed of supercomputers has hardware set up not just for speed, but also to better tackle large networks of seemingly random data. But old software won’t run on the new hardware any more than a PC program will run on a Mac.

Now, a group of researchers from a handful of institutions is developing software for these supercomputers.

New supercomputer applications can be found anywhere that complex webs of information reside, from Internet security and power-grid stability to complex biological networks, according to researchers working on these supercomputers.

The difference between the new supercomputers and traditional ones is how they access data, a difference that significantly increases computing power.

“Traditional supercomputers are not well suited for certain kinds of data analysis, so we want to explore this advanced architecture,” said Daniel Chavarría, a computer scientist at the Pacific Northwest National Laboratory in Richland, Wash.

The Department of Defense has provided $40 million to seed the Center for Adaptive Supercomputing Software, a joint project between the Pacific Northwest lab and Cray Inc. of Seattle. Other researchers in the software collaboration are from Sandia National Laboratories, Georgia Institute of Technology, Washington State University, and the University of Delaware.

The processors and computer memory in the advanced computers interact in a novel way. In traditional supercomputers, each processing chip gets a dollop of memory to use for its computations. To perform a calculation, the chip dips into the memory, does its work, then accesses the memory again for its next calculation, like an elephant dipping its trunk into a bag of peanuts and eating them one at a time. Each processor-memory unit is linked together over a network, and performance improvements come with more and faster processors and sleek network connections.

The new supercomputers operate via so-called multithreaded processors, which lump all the memory together. The processors freely access the much larger memory pool. But like an elephant with many trunks, each processor has multiple threads: It dips into memory with one thread, and while that thread is performing the calculation at hand, another thread goes into the memory, and others perform different tasks, Chavarría said.

By the time all the threads have dipped, the original thread has finished its calculation and is ready for another trip to the memory bank. An elephant with many trunks would have a distinct speed advantage plowing through a bag of peanuts over its hungrier zoo-mate, just as a multithreaded system does, he added.

“The processors are doing useful work all the time, so the computer can be faster,” Chavarría said.

Now all the supercomputers need is software, which Chavarría and other researchers at work on the software project hope to have up and running soon.

A FONT FOR YOU

Insert your key in the ignition of your luxury car, and the seat and steering wheel can automatically adjust to a programmed position that fits your body proportions. Stroll through the rooms of your mansion, and each room can adjust its lighting, temperature, and music to accommodate your personal preferences.

But open any computer program, and you’re largely subject to a design team’s ideas about button sizes, fonts, and layouts, according to a team of researchers working to change that.

A new approach to design, developed at the University of Washington in Seattle, would put each person through a brief skills test and then generate a version of the user interface optimized for his or her vision and motor abilities, said Krzysztof Gajos, a UW doctoral student in computer science and engineering.

Off-the-shelf designs are especially frustrating for the disabled, the elderly, and anybody who has trouble controlling a mouse, Gajos said.

“Assistive technologies are built on the assumption that it’s the people who have to adapt to the technology,” Gajos said. “We tried to reverse this assumption and make the software adapt to people.”

His collaborators on the project are Dan Weld, a professor of computer science and engineering at the university, and Jacob Wobbrock, an assistant professor in the university’s information school.

The system, called Supple, begins with a one-time assessment of a person’s mouse pointing, dragging, and clicking skills. A ring of dots appears on the screen and as each dot lights up, the user must quickly click on it. The task is repeated with different-size dots. Other prompts ask the participant to click and drag, select from a list, and click repeatedly on one spot. Participants can move the cursor using any type of device. The test takes about 20 minutes for an able-bodied person or up to 90 minutes for a person with motor disabilities.

An optimization program then calculates how long it would take the person to complete various computer tasks. In a couple of seconds, it creates the interface intended to maximize that person’s accuracy and speed when using a particular program.

Deploying this system would require a radically different approach to designing computer interfaces, Gajos said. For that reason, researchers also plan to look at adapting interfaces that were designed in the traditional way into ones that Supple can use.

Briefly Noted

Spatial Corp. of Broomfield, Colo., which makes 3-D software components for technical applications, is now shipping its 3D Springback Component. This product facilitates a one-step method for Springback correction of 3-D models within pressed-metal-tooling manufacturing applications.

Geometric Ltd. of Mumbai, India, which develops product lifecycle management solutions, has released version 2.2 of GeomCaliper for Catia version 5 and GeomCaliper for Pro/Engineer. Upgraded features relate mainly to performance improvement.

Laser Design Inc. of Minneapolis, a provider of 3-D laser scanners, has released an updated version of its Surveyor Scan Control software, which scans operations and collects 3-D point cloud data using the Laser Design Surveyor 3-D scanning systems.

The Open Design Alliance of Phoenix has launched Education and the ODA, a program aimed to stimulate research by educational organizations in CAD, CAM, and other engineering software applications.

The tutorials section of the AutoCAD LT site, created by Autodesk of San Rafael, Calif., now has several tutorials with sample files available for download. Topics include annotation scaling, multileaders, and tables.

Kubotek of Marlborough, Mass., a maker of CAD software, is now shipping KeyCreator 7.5.3 for customers with active maintenance. The 7.5.3 downloads are available now from the Kubotek support area on the developer’s Web site.

Version 2.1 of the project management software Clarizen is now available from Clarizen of Mountain View, Calif. The software allows project managers across manufacturing, design, and services industries to integrate this project management solution with the various applications they use daily.

Blue Ridge Numerics of Charlottesville, Va., has released CFdesign version 10, an upgrade to the company’s computational fluid dynamics software.

Roland DG Corp. of Hamamatsu, Japan, has released SRP Player Pro, a surface-based CAM program for product design, including prototyping, production engineering, jig creation, and customized part and mold production. The software is designed for use with the developer’s Roland MDX series of 3-D milling machines.

A developer of multi-CAD design data, project, and document management applications, Concurrent Systems Inc. Ltd. of Newbury, England, has released DesignDataManager 2008.1.