This section was written by Associate Editor Jean Thilmany
Analysis of a Dinosaur's Head
||A researcher at Cambridge
University in England is merging paleontology with finite element analysis
in order to study the jaw of a dinosaur that has been extinct for 65
Emily Rayfield, an earth sciences doctoral student at the school, has been studying the Allosaurus fragilis, a theropod from the Jurassic period whose fossilized remains have been found at numerous sites in the United States and Europe. The Allosaurus has an unusual skull: an intricate arrangement of interlocking webs and cavities, which makes the roughly 2 1/2-foot (80-centimeter) skull surprisingly light, she said.
With the help of finite element analysis software, Emily Rayfield, an earth sciences doctoral student at Cambridge University, studies the Allosaurus fragilis, a theropod from the Jurassic period.
"This skull is able to achieve lightness through such a complex design that it can't have happened without a functional reason," Rayfield said. "I'm trying to find out how this apparently carefully evolved bone structure translated into biting strength to see if it can further our understanding of how Allosaurus hunted and fed."
To aid her research, Rayfield uses a desktop-based FEA program called Cosmos, from Structural Research and Analysis Corp. of Los Angeles. She uses the software to analyze the flow of forces within the Allosaurus skull, using her best guess for typical loading capacity.
Rayfield and her team use a skull that came from a site in the Rocky Mountains in Colorado.
For day-to-day measurements, they use a full-size plastic cast of the skull, but to capture the complete geometry accurately, the original fossil was subjected to a computer-aided tomography, or CT, scan at a local hospital. They used the resulting point-cloud data as the basis for a CAD model of the skull, which they can then analyze, Rayfield said.
For skull analysis, researchers work with a computer-aided tomography scan of the dinosaur's head.
To set the boundary conditions for skull analysis, she estimated the forces exerted by the dinosaur's jaw muscles. Few clues remain about the muscle tissue, so Rayfield had to reconstruct the anatomy as best she could in order to calculate muscle strength. To determine the material properties of the bones, Rayfield looked to the properties of fast-growing mammals, like cows, which are known to share common bone properties with dinosaurs.
She uses these principal values in the FEA equation to perform the analyses. She runs the analyses on the skull as though each skull bone were fixed in place, although, in actuality, some of the bones did move relative to each other, she said. She sometimes tries to permit movement between these bones and to model individual muscles into the FEA software for greater accuracy.
Rayfield's thesis still has a way to go, she added. But already she is uncovering some interesting facts, she said.
"I've discovered that although the skull is incredibly lightly built, it's actually very strong," she said. "Differences in magnitude between biting forces and maximum loads the skull can withstand before yielding are leading me to some interesting conclusions about how this animal may have captured and fed upon its prey."
|Low-Power LANs Have Low Error Rates
||Penn State engineers have
shown that broadband, wireless, indoor local area networks, or LANs, that
rely on non-line-of-sight infrared signal transmission can offer low error
rates as well as safe, low power levels.
"Line-of-sight, or point-to-point infrared signal transmission, which is used, for example, in television remote controls, is highly efficient at low power levels, but suffers from the need for alignment between the transmitter and receiver," said Moshen Kavehrad, a professor of electrical engineering at Penn State in University Park. "If someone blocks the remote control beam while you're trying to change the channel, the signal can't get through.
"On the other hand," he added, "non-line-of-sight transmissions, which use a broad, diffuse beam, suffer less from shadowing, but usually forfeit the power efficiency that broadband and low-error-rate-values infrared transmission can offer."
Kavehrad and his colleagues at Penn State's Center for Information and Communications Technology Research have developed a link design that uses a multibeam transmitter with a narrow field-of-view receiver. The system has a bit-error rate of one error per billion bits and uses milliwatt transmitted power levels, Kavehrad says.
For example, to form a LAN for a group of computers using the new link design, each machine in a room would be equipped with a low-power infrared source and a holographic beam splitter.
The original low-power beam would be separated into several narrow beams that strike the ceiling and walls at points that form an invisible grid throughout the entire volume of the room. Because the beams are also reflected at each of the strike points, they can be used to send or receive information.
Cycle Reduced By 14 Months
||When the Bresslergroup of
Philadelphia, which supplies products to the consumer, medical, office,
and industrial goods industries, was asked six years ago to produce a
rather unusual product—a tire gauge that used a readable LCD display to
note tire pressure—the company responded with a product designed via
two-dimensional and 3-D CAD systems.
But upgrades and CAD system migrations since that time have made the design process much more streamlined.
Measurement Specialties Inc. of Fairfield, N.J., which made the request, had decided to break into the digital tire pressure gauge market, according to Peter Bressler, Bresslergroup's founder and president. The gauge would be sold through upscale stores and catalogs.
The models look advanced and are reliable, but aren't prohibitively costly, Bressler said. The LCD displays are backlit so they can be read at night or in poorly lit places, and the gauges feature materials such as elastomer, rubber-like handles and brushed aluminum housings.
As part of the design phase, Bresslergroup engineers took into consideration calibration, airflow patterns, and electrostatic discharge shielding. A tire gauge must be a very accurate piece of equipment, Bressler noted.
Bresslergroup cut design cycle time of tire gauges from 20 months to six months because all suppliers and contractors migrated to the same CAD software from PTC of Waltham, Mass.
At the beginning of the companies' partnership, MSI was establishing product development and manufacturing groups in China that would work with Bresslergroup to develop the product. The Chinese group used AutoCAD, from Autodesk of San Rafael, Calif., for CAD design, while Bresslergroup had recently moved from 2-D to 3-D design with the use of Pro/Engineer CAD software from PTC of Watham, Mass., Bressler said.
Working with MSI's New Jersey-based and China-based design and manufacturing groups, Bresslergroup completed the first digital tire gauge using AutoCAD 2-D software. For a second project, Bresslergroup designers used both AutoCAD and Pro/Engineer. By the time MSI asked for a third design, the Chinese group had also moved to Pro/Engineer.
"Subsequently, all projects have been paperless and much more efficient," Bressler said. "Having a common format makes exchanging engineering data much more efficient."
As a result, the product development cycle for these tire gauges has been reduced from nearly 20 months to just six months from conceptualization to production, he added.
With CAM Cuts To the Chase
||Stanley Works of New
Britain, Conn., a maker of tools, hardware, doors, fastening systems,
automatic doors, storage systems, and hydraulic attachments, recently
asked one of its regular mold-making suppliers, Newport Tool and Die, to
consolidate the design of two utility knives into one common set of molds
to save costs in tooling and to expand the features of both knives.
Newport Tool and Die of Middletown, R.I., had previously built tooling for Stanley and had also been making product-design modifications to its tools for some time. The partnership had come to include design collaboration. Since the company was primarily a mold maker, executive interest at Newport had been primarily in computer-aided manufacturing software rather than CAD software. Company designers began using 2-D CAD in the late 1990s, but as the relationship with Stanley grew, executives felt they needed to upgrade to 3-D software, according to Mark Nardelli, Newport Tool and Die shop manager.
The company chose a 3-D CAD package that includes integrated CAM software in order to get CNC machining, mold design, and 3-D design capabilities within one software system, he added.
With the software, called VX, from the company of that same name in Palm Bay, Fla., Newport Tool was able to incorporate into one set of molds the best features of two distinct models: a safety knife with a mechanism that automatically retracts the blade, and a utility knife with a fixed and exposed blade. Using the existing designs of both knives, Newport designers could create a new model, Nardelli said.
The resulting model incorporates the safety knife retraction feature into a utility knife that has two distinct design elements: the blade slider and the blade itself.
Previously, Newport Tool had used 2-D designs and would use initial graphics exchange specification, or IGES, translations, or work with paper drawings to create tool paths. The company now uses the same software for CAD and CAM as well as for IGES translation, which is also included in the software. Toolpaths that would be used to make the product were then created from the CAD software.
With help from the software, Nardelli estimates that turnaround time for the project will drop from three weeks to six days.
|Analyst: PDM Market Is Moderating
||A recent industry report
from CIMdata, a consulting and research firm in Ann Arbor, Mich., contends
that the product data management market is easing back to more moderate
levels following a 62 percent expansion in 2000.
The report did not take into account economic factors following the September 11 World Trade Center tragedy.
The 2000 spike in growth was attributed to widespread adoption of PDM software as a method of operating in increasingly competitive global markets, said Ken Amann, CIM-data's director of research. The PDM market reached a turning point in terms of acceptance and demand last year, with industrial organizations committing to record levels of investment, he added.
According to the study, called CPDM Market Analysis Report for 2000, the full impact of the general economic slowdown initially felt in the second quarter in the United States would not be evident in the PDM market until the third quarter of 2001. In the report, CIMdata projected a compound annual growth rate of 36 percent through 2005, when it expected market size of $13 billion.
Continued growth should come about through a middle market of adopters, the emergence of visualization tools and document and content management technologies for collaboration, and the expanded software tools that allow more engineers and engineering firms to find an appropriate use of the PDM products, according to the report.
|Software Aids Emergency Workers
||Software developed at
Pennsylvania State University in University Park for use with handheld
computers aims to help ambulance personnel collect more data at the
emergency site and give additional information to hospital emergency
departments, according to Janet Jonson, an associate research engineer at
Penn State's applied research laboratory. She leads the project team that
developed the software.
The program uses a small diagram of the human body on the handheld screen to speed information entry about the type and location of a victim's injuries. Ambulance personnel click on the digital figure to mark where the patient has been injured. This lets the software record injury information automatically.
For example, clicking on the figure's right arm records the location of the injury. The person using the computer can then select the type of injury from a drop-down list. Vital signs, including blood pressure, pulse, and EKG number can also be entered by point-or-click, or drop-down list methods.
That information can then be digitally transferred directly to the emergency department at the hospital at which the patient will be arriving. Or, ambulance personnel can transfer the information by beaming it from the handheld device to a hospital printer.
"Field trials are showing that the new software enhances record accuracy," Jonson said. "It can also help ambulance personnel provide a higher level of patient information and save significant amounts of time by completing this pre-hospital trip report."
||Technology maker ABB of Zurich,
Switzerland, has acquired a minority interest in software provider
Industrial and Financial Systems AB of Linkoping, Sweden, a maker
of business software.
A maker of computer-aided engineering software, ANSYS of Canonsburg, Pa., and Enductive Solutions, a subsidiary of Aavid Thermal Technologies of Scotts Valley, Calif., have formed a partnership to develop custom-built CAE applications.
IronCad of Atlanta, a maker of CAD software, has released its software IronCad version 2.4J for the Japanese market. n A maker of CAD software, Think3 of Santa Clara, Calif., has released an upgrade to what the company calls its mass 3-D software, Think-design.
An Atlanta provider of Web-based document collaboration, distribution, and plotting software, eQuorum Corp., has released ImageSite 3.2, which provides a combination of document management and distribution, and online collaboration abilities with a printing feature.
Aegis Industrial Software of Philadelphia, a maker of computer-integrated manufacturing software, has released CircuitCAM, a CAD and CAM data preparation, documentation, and off-line machining software program.
A maker of Web-enabled data visualization, numerical analysis, and enterprise software, Visual Numerics of Boulder, Colo., has upgraded its PV-Wave software to newly released version 7.5.
Engineering.com of Woodbridge, Ontario, and Translation Technologies Inc. of Spokane, Wash., have formed a strategic alliance to deliver CAD interoperability software and other capabilities to the engineering community via the Engineering.com Web site, according to the company.
Right Hemisphere of Los Angeles has released 3D Exploration Enterprise Edition version 1.8, the company's upgrade of its Web publishing software.
A maker of CAD and CAM software for the tooling industry, Cimatron of Livonia, Mich., has released its wire-electrical discharge machining programming software, which features two- to four-axis capabilities.
© 2001 by The American Society of Mechanical Engineers