The development of morphing aeropropulsion structural components offers the potential to significantly improve the performance of existing aircraft engines through the introduction of new inherent capabilities for shape control, vibration damping, noise reduction, health monitoring, and flow manipulation. One of the key factors in the successful development of morphing structures is the maturation of smart materials technologies.
In NASA Glenn Research Center’s Structural Mechanics and Dynamics Branch, analytical efforts are ongoing to develop comprehensive finite element models for smart materials to facilitate the experimental characterization of these materials. Finite element studies have been conducted to investigate the impact of stacking and curvature on the force and displacement response of piezoelectric actuators (ref. 1). Experimental studies are also being conducted to characterize a variety of different smart materials in the Smart Materials and Structures Laboratory at the University of Akron under a cooperative agreement. Shape memory alloy actuators have been used to achieve precision position control while reducing energy consumption (ref. 2). Several prototype magnetorheological fluid devices have been developed to investigate the capability to instantaneously damp out motion and to statically hold a position under applied loads. Also, piezoelectric actuators have been successfully used to compensate for thermal distortions generated by film heaters in a composite beam (ref. 3).
Experimental setup for composite beam with attached piezoelectric actuators subjected to thermal loading.
Long description of figure 1.
Comparison of the initial thermal deformation at the free end of the beam with the controlled deflection.
The photograph shows the experimental setup for the cantilevered composite beam with attached piezoceramic patches subjected to thermal loadings, along with the instrumentation required to control and acquire data. The graph depicts the corresponding deflection with time near the free end of the beam. The open-loop position indicates the initial thermally induced deformation of the beam, whereas the closed-loop position shows the compensated deformation achieved by activating the piezoceramic actuators. By returning the beam to the original desired position, this research demonstrates the potential use of smart materials for shape control to achieve morphing structures.
Glenn contact: Dr. Ho-Jun Lee, 216-433-3316, Ho-Jun.Lee-1@nasa.gov
Authors: Dr. Ho-Jun Lee and Prof. Gangbing Song
Headquarters program office: OAT
Programs/Projects: RAC
Last updated: June 25, 2003
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