TOP STORY

UD-CCM Research Paves the Way for Improved Understanding of Flexible Fabric Mechanics

By Diane Kukich

In a complementary project, Professor of Chemical Engineering Norm Wagner, has developed new materials based on shear-thickening fluids. “Norm has found that the fluid increases the interactions between the yarns and increases their ability to share load,” Keefe says. “What we're doing is developing a model of the fabric at the yarn level.”

Keefe's research group has included postdoc Yiping Duan and several undergraduate researchers. “We've also gotten a lot of guidance and help from ARL,” says Keefe. “Bryan Cheeseman helped with the initial finite-element setup, while Brian Powers has contributed to the finite element work during the past three years. In addition, Travis Bogetti has helped us focus the parameters we're studying, and Eric Wetzel has assisted with testing.”

Parameters include the size and shape of the penetrator, the velocity of the penetrator, boundary conditions, interaction effects, and material properties.

“What we've found is that friction, as expected, does play a role,” Keefe says. “But it's not so much in absorbing energy, which is what we expected, as it is in maintaining the integrity of the fabric—that is, the fabric remains intact in front of the impacting object.”

“However,” he continues, “if the integrity of the fabric is too high and the yarns are ‘locked together,' then they break rather than providing protection. We're dealing with a complex problem of optimization.”

The results thus far suggest that controlling yarn-yarn friction shows promise as a way to improve impact protection, with the model affording the capability to capture a number of variables. But, as Keefe points out, scale-up is another issue. The researchers have been using 2x2 coupons to test their predictions, but the materials will actually be used in fabrics fashioned into garments that will cover the arms and legs.

Keefe is also interested in investigating interactions at a smaller scale. “Each yarn is made up of a number of fibers,” he points out, “and to really capture failure, we have to look at the fiber-yarn level as well. In effect, we started in the middle of the scale by looking at the yarns, but our future work will be multi-scale, going all the way from the fiber to the yarn to the fabric.”

OTHER NEWS

Composites Manufacturing Training Extended to Hexcel

By Diane Kukich

Based on the success of its composites manufacturing training program for the Boeing Company, UD-CCM offered similar hands-on, lab-based training to employees of Hexcel Reinforcements on March 7 and 8, 2006. Hexcel ( http://www.hexcel.com/ ) is one of the world's leading advanced structural materials companies. “The training program was very well received by our entire group at Hexcel, which included a wide range of liquid molding experience,” said Brian Laufenberg, R&T Manager.   Bryan Loeper, Aerospace Market Development Manager, was also a satisfied customer. “The UD-CCM Workshop provided an opportunity for our associates to better understand the dynamics related to making VARTM parts,” he said.

Hexcel trainees and UD-CCM researcher Hope Deffor infusing a complex shape part in the 2Phase tooling using the VARTM process

“The classroom presentations were informative and provided a setting to learn more about the leading technologies available to predict process performance.  Based on my experience, I would recommend this workshop and future advanced training at UD-CCM to anyone involved in direct process manufacturing of composite parts.”

“We're continuing to develop more advanced classes for companies who have already been through the training,” says Dirk Heider, Assistant Director for Technology at CCM, “and we're inviting input from former participants in our planning for these sessions. We'll also tailor future training to the specific needs of our industrial customers.”

UD-CCM Participates in International Composites Exhibition

By Diane Kukich

UD-CCM was one of some 900 exhibitors at the JEC Composites Show last month— but one of only a handful of academic institutions with a presence at this international exhibition. Held in Paris from March 28–30, 2006 , the JEC Show is pegged as “the world's leading composites event.” JEC supports the development of composites through the dissemination of knowledge and the promotion of exchanges between suppliers and users. Most of the exhibitors were small, medium, and large companies in the p rocessing, raw materials, equipment, distribution, and service sectors.

UD-CCM's booth at the show was manned by Assistant Director of Technology Dirk Heider, Associate Scientist John Tierney, and Ph.D. candidate Solange Amouroux. Visitors to the booth included companies interested in the Center's capabilities, as well as students inquiring about internship opportunities.

Of particular interest were CCM's displays on the CDS software suite, LIMS and membrane-based VARTM.

According to Amouroux, other visitors were drawn by CCM's reputation in the areas of sensors, training, design support, and new fibers and resins. “European interest in organizations such as CCM, with its focus on fundamental and applied research directed towards industrial needs, is growing,” she said.

A number of companies expressed an interest in joining the Center's Industrial Consortium. “We plan to follow up with everyone who visited,” said Heider, “so that we can learn more about how we can meet their individual needs.”

“Some of the companies are interested in our software,” he continued, “while others want to learn more about our composites training such as the programs we've already presented to Boeing and Hexcel.

With “Composites for Better Living” as the theme, the 2006 JEC Show featured a broad range of products, from suitcases, helmets, ladders, bicycles, and sinks to state-of-the-art applications for Formula One racing, aerospace, and construction applications.

“We were delighted to participate in this ‘global marketplace,'” said Heider. “I think just being there lifts us above the rest of the academic world for many of our visitors. Only two or three other academic organizations were present, and they were all European institutions.”

Michael Fuqua selected as SAMPE Finalist

Mike Fuqua, a senior in mechanical engineering, has been selected as a finalist for a SAMPE student research award - as a result, he has been invited to present his work at the annual SAMPE meeting May 2, 2006 at Long Beach Convention Center in Long Beach, CA. Mike has worked with Prof. Glancey as a Science and Engineering Scholar and an Honors Degree with Distinction Candidate on flood VARTM and port-based injection and control for VARTM.

The Investiture of Nancy Sottos – UD-CCM, Mechanical Engineering Alumnus

The investiture ceremony of Nancy R. Sottos, Donald Biggar Willett Professor in the College of Engineering of University of Illinois at Urbana-Champaign will be held on April 26th at the Beckman Institute. For details go to http://tam.engr.uiuc.edu/

Michael Chajes Civil & Environmental Engineering Chair Re-Appointment

Michael Chajes has agreed to accept a second term as chair of the Department of Civil and Environmental Engineering. “The review committee was unanimous in their view of Michael's effective and enthusiastic leadership of CEE”, said Dean Kaler.

CONSORTIUM

CCM would like to welcome Sparta, Inc., San Diego, CA, for the recent renewal of their membership and for continuing to participate in consortium activities.

NEW PUBLICATIONS

Journals

Amouroux, S. C., D. Heider, and J. W. Gillespie, Jr., “Membrane-Based VARTM: Membrane and Resin Interactions,” JEC Composites Magazine, No. 24, pp. 41-43, April 2006.

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