Fundamental Hyperelastic Material Study

This research is part of an innovative effort to use hyperelastic materials to produce flexible and seamless aircraft structures that reduce drag and minimize acoustic noise. Hyperelastic materials, such as rubber, have a non-linear stress-strain relationship, which often complicates the modeling process. Therefore, CIF funding is being used to gain increased knowledge regarding the properties of hyperelastic materials and develop improved finite element analysis (FEA) models. This research effort builds on the knowledge gained from the Adaptive Compliant Trailing Edge (ACTE) experimental flight research project. The ACTE project will demonstrate the structure technology in flight, and this technology has been shown to improve aircraft aerodynamic efficiency and reduce airport-area noise generated during takeoffs and landings.

Work to date: The Armstrong development team has fabricated the biaxial strain test hardware and completed initial bubble test planning. The team is working to obtain biaxial strain properties and develop an FEA model that simulates the material properties and failure characteristics. In 2014, the team fine-tuned the modeling by comparing the predicted output to an actual bubble test of the material.

Partner: FlexSys Inc. is the industry partner on this effort, as it owns the design patent.

Benefits

• Economical: Use of hyperelastic material increases fuel efficiency by reducing drag
• Quieter: Novel wing flap reduces noise associated with takeoffs and landings both in the aircraft cabin and on the ground

Applications

• Aircraft wing flaps
• Helicopter blades
• Motor vehicles
• Trains
• Ships