Third Wave Systems Completes Military Contract for Machining Composites
The company developed a physics-based approach to five-axis machining of polymer matrix composites used in warfighters for the U.S. Air Force.
Third Wave Systems (Minneapolis, Minnesota) has delivered results on a $3 million U.S. Air Force contract made in 2013, one of the largest-funded projects in the company’s 20-year history. The focus of the project was to expand the company’s metalcutting solutions to polymer matrix composite (PMC) materials used on the latest warfighter programs. The Department of Defense Rapid Innovation Fund (RIF), which was designed to transition technologies that resolve operational DoD challenges, allocated funds for the contract.
Developed under the RIF, Third Wave Systems software products reduced machining cycle times by predicting and managing forces and predicting composite behavior. Engineers from the company demonstrated improved production processes for several current warfighter PMC components (current warfighters are about 35 percent composite materials). The improved processes utilized in-place machining equipment, obtained greatly improved part quality and surface finish, reduced tooling costs by 27 percent and reduced cycle time on milling operations by 47 percent.
The results delivered by Third Wave Systems met all proposed goals and exceeded expectations, the company says. The work was transitioned to production at a major OEM. Third Wave Systems used its existing software as the technology platform. The software was used to model the machining of PMCs at the tool-workpiece level, and machining was completed to validate the model outputs. Engineers also modeled PMCs at the toolpath level. The analysis gave engineers the ability to model CNC machining operations on full part programs. Engineers were then able to predict and optimize forces and temperatures during machining and control them through feed and speed selection. Additionally, Third Wave Systems also used its modeling technology to select cutting tool strategies to eliminate part delamination and improve quality.
Working closely with Third Wave Systems throughout the two-year project were several warfighter component suppliers including GKN Aerospace, who was the primary project partner. Third Wave Systems developed, validated and implemented a physics-based machining model of the Cycom 5250-4 bismaleimides (BMI) composite material. Additionally, Triumph Group along with major composite machining supplier Janicki Industries worked with Third Wave Systems to perform similar activities for resin systems Cycom 977-3 and AFR-PE-4.
With approval from the Air Force program manager, Third Wave Systems also completed a brief experiment in modeling composites drilling for a project partner’s supplier that had experienced devastating quality issues from their baseline drilling process. The drilling experiment was fully successful for this application. While the initial results are promising, showing 56 percent cycle time reduction and 100 percent quality improvement, more work still needs to be completed to validate the findings and incorporate composite drilling into the software. However, a major advantage is that the drilling technology will be developed using the same physics-based modeling approach. This means the development risk is low and production implementation will be efficient and require no new hardware.
