The 1988 crash of United Airlines Flight 232 in Sioux City, IA, might have been prevented if the computer-aided tomography (CAT) scan data and visual analysis techniques used by Ron Kriz and his collaborators at NASA Langley had been available. The cause of the crash was a crack in a turbine fan blade in the aircraft's engine-- a flaw not always detectable by conventional ultrasonic non- destructive testing.
Kriz, NCSA's academic affiliate representative from Virginia Polytechnic Institute and State University (Virginia Tech), came to Champaign-Urbana in the summer of 1992 with a set of data supplied by the manufacturer of QUEST, a CAT-scan system that detects small flaws in advanced material systems. Using NCSA's visualization software (i.e., X DataSlice Isosurface, Viewit, X DataSlice Dicer, and X Image), Kriz transformed the complex dataset into an image of a turbine fan blade--with a serious flaw hidden in the center (see image above left). The results of his visual analysis efforts helped Kriz secure a contract with NASA Langley Laboratory, which had just acquired a QUEST system of their own for materials analysis.
With the financial backing of the High Performance Polymers and
Adhesives NSF Science and Technology Center and the Virginia
Institute for Material Systems, and space from his department,
Kriz formed the Scientific Visual Analysis Laboratory at Virginia
Tech. The facility, which is open to any Virginia Tech faculty
member, is equipped with two Macintosh IIfx computers with
multimedia capabilities, two Sun SPARC 1 workstations, two Sun SPARC 2
workstations, and one Silicon Gra-phics IRIS-4D/320 VGX system.
Most of the lab's software programs are from NCSA's Scientific
Visualization Software Suite produced by the
Software Development Group
(SDG). All these efforts led Digital Equipment Corporation
to start a digital visualization reference center in the visual
analysis lab.
"After building the laboratory," says Kriz, "I returned to NCSA to learn how to use the visual analysis tools. The support I received from the folks at NCSA, especially those in Joe Hardin's [SDG] group, was really fantastic. There was hardly any learning curve at all, which translated back to my students and colleagues at Virginia Tech. As an academic affiliate representative of NCSA, I can provide the people working in the laboratory a choice of computers and software."
Kriz has brought NCSA's visual analysis tools to the classroom as well. He created a new course in scientific visual analysis, during the same busy summer that he put together the Visual Analysis Lab, and came to NCSA to learn to use visualization tools. Students in the course, popular among engineering students in a number of areas, develop projects in scientific visual analysis that culminate in multimedia presentations.
"This eventually helped to support the creation of a new multimedia laboratory for undergraduate education," says Kriz, "as part of the NSF SUCCEED program." Virginia Tech is one of eight southeastern universities that comprise SUCCEED (Southeastern University and College Coalition for Engineering Education). "We're anticipating that we will be using NCSA sonification tools in our multimedia lab," Kriz continues. "The director of that lab, Gordon G. Miller III, is interested in using NCSA visualization tools, like Image and DataScope, in the lab."
During the summer of 1993, three undergraduate students worked with their professors at Virginia Tech to develop multimedia training modules for undergraduate courses in chemistry, materials science, and engineering science and mechanics. Funding was provided by the NSF Science and Technology Center Summer Research Undergraduate Program. Virginia Tech has an anonymous ftp site to distribute the multimedia modules, which are specifically geared to engineering students. Enter ftp viz2.multimedia.vt.edu to obtain these modules. Username is anonymous; password is E-mail.
Multimedia applications are deemed so important to the College of Engineering's curriculum that this fall's freshman class is required to have computers that can handle multimedia applications such as animation, graphics, photographs, full-motion video, and sound. For nearly a decade, the college has required students to have their own computers.
An acoustic microscope differs from an optical microscope in that
it uses stress waves (sound waves traveling through a solid
material), rather than light waves. "Stress waves do not just
reflect off the surface of a material," says Kriz. "They penetrate
and can reflect off structures below the surface as well.
"The materials I am studying--fiber-reinforced epoxy polymers--have fibers below an epoxy polymer surface. The area where the fibers bond to the polymer forms an interphase--not a fiber, not a polymer, but something in-between."
Kriz plans to use NCSA's CM-5 to simulate the propagation of stress waves below the surface of the polymer and the reflection off the fibers below. After running the simulation and visualizing the nature of the interphase, Kriz can better interpret the actual measurements from the acoustic microscope.
"This is the first time," Kriz adds, "that anyone has ever experimentally measured these interphase structures by stress wave propagation. The objective is to bring the two--simulation and visualization, and experimental measurement--together. We're getting there."
NOTE: Virginia Tech's Visual Analysis Lab has posted material on its Gopher server. Using NCSA Mosaic, select the NCSA Mosaic Home Page, then World Wide Web; W3 servers; Virginia Tech (under Virginia); Visualization Lab.
