CCM is part of a team led by Northrop Grumman Ship Systems (NGSS) that has been selected to develop a predictable and repeatable resin infusion process for fabricating carbon/vinyl-ester composite structures. The $870K project was awarded by the Center for Naval Shipbuilding Technology (CNST) through its partnership with the Office of Naval Research and Navy ManTech.

The CNST award is yet another outgrowth of the strong foundation CCM has built in this area since the Office of Naval Research established the Advanced Materials Intelligent Processing Center (AMIPC) at CCM in 1997.  Under the AMIPC, Center researchers have created a suite of hardware and software tools including mold-filling simulations, sensor technologies, active controllers, versatile resin injection systems, and mold design methodologies for liquid composite molding processes.

“The Navy definitely understands the value of these tools,” says Suresh Advani, Co-PI of the AMIPC program, “and they’ve been taking a proactive role in getting companies who make components for them to use these tools to reduce costs and eliminate part variability.”

The VARTM process has traditionally been used to manufacture glass-fabric laminates and sandwich constructions.  The new Navy program will focus on the use of carbon fibers, which yield lighter composites with improved performance but can present manufacturing challenges. 

“The problem is that the high manufacturing success rate achieved with glass-reinforced composites has not translated into the same quality for carbon parts,” says Dirk Heider, CCM Assistant Director for Technology.  “Successful manufacture of carbon-reinforced marine structures like the DDG-1000 deckhouse will depend on meeting quality requirements and reducing the scrap rate.” 

That’s where CCM comes into the picture.  The Center offers the two key components of smart manufacturing—(1) a virtual manufacturing environment based on developments in flow modeling that has been packaged into a user- friendly computer simulation called Liquid Injection Molding Simulation (LIMS)  and (2) an intelligent VARTM workcell to control the process once the ideal processing parameters have been identified using the models. 

“The goal is to minimize dry spots and eliminate voids,” says Heider.  “This becomes increasingly challenging with parts of significant thickness or geometric complexity.”  Infusion modeling methodologies and flow sensor technologies can enable optimization of techniques for more complete infusion of low-permeability fabrics.

The new program, led by system integrator NGSS, will enable the tools developed by CCM to be transitioned and validated on actual large-scale components.  The twelve-month initiative will employ a “design of experiments” methodology and leverage resources from Navy ManTech’s Composites Manufacturing Technology Center and the NGSS Composites Center of Excellence, as well as CCM’s industrial consortium. According to NGSS, material savings alone are estimated at $1.7M per hull; in addition, significant labor costs will be realized via avoidances for set-up, quality assurance, and rework.

The resin flow modeling technology will be implemented at the NGSS Gulfport Operations facility.  Center researchers have already made significant contributions to manufacturing operations at that site.  “We worked on a pilot program with Northrup Grumman to demonstrate the value of the tools on some parts that they were having difficulty manufacturing,” Advani explains.  “A team from CCM went to their Gulfport facility and successfully used the tools to fabricate the components.”

For CCM , the new program with industry and the Navy is more than just a new funding award—it’s yet another opportunity to demonstrate that the Center’s approach to intelligent manufacturing works and that it can lead to better composite parts at lower cost.  And it’s also further evidence that the Center can play an integral role in technology transition.

Space Cadets from the Delaware Aerospace Academy built
composite beams during the 2007 Space Beam Challenge

Space Beam Challenge Returns to CCM

by Diane Kukich

Nineteen pieces of balsa wood, twelve pieces of foam, ten pieces of steel, eight honeycomb panels, eight pieces of aluminum, various carbon and glass fibers, and lots of epoxy—these were the materials used by the twelve teams participating in CCM’s “Space Beam Challenge” on July 12, 2007.

Sponsored by SAMPE and CCM and supported by donations of materials from industry, the Space Beam Challenge is one component in the Delaware Aerospace Academies, a series of camps offered by the Delaware Aerospace Education Foundation to provide students in grades two though ten with hands-on training and experiences in aerospace-related activities and fields.  The Space Beam Challenge is part of an academy targeted to eighth, ninth, and tenth graders.

The teams, named after various space missions such as Eagle and Aquarius, were given an overview of the various types of materials and the reason composites are chosen over traditional materials.  Then they took what they had learned and applied it to the design of beams that they hoped would be strong but lightweight.  The success of their efforts was judged when their beams were tested to failure in CCM’s lab.

“That’s a point we try to get across to the kids,” says master’s student Justin Clews, who led the organization of this year’s event.  “They have to consider both strength and weight in arriving at their design.  As expected, this year’s winner was neither the lightest nor the strongest, but it did have the best strength-to-weight ratio.”

Intrepid 2 won the 2007 challenge with a beam having a load/weight ratio of 4869.  Their beam featured a honeycomb core with balsa wood on either side and carbon-epoxy face sheets as the outer layer.  Five of the beams, including the winner, were symmetric, while the remaining seven comprised asymmetric stacking sequences.

Center staff and students have participated in the challenge for the past eight years.  “It’s a great program,” says Clews.  “It gives middle school students an opportunity to learn about engineering in a hands-on way.”

“CCM is committed to composites education,” says Director Jack Gillespie, “not only of UD undergrads and graduate students but also of K-12 students as well as practicing engineers.  We’re pleased to offer our facilities and expertise for this program, and we’re grateful to our industrial partners for providing materials and to SAMPE for financial support.”