Applying smart materials in aeropropulsion systems may improve the performance of aircraft engines through a variety of vibration, noise, and shape-control applications. To facilitate the experimental characterization of these smart structures, researchers have been focusing on developing analytical models to account for the coupled mechanical, electrical, and thermal response of these materials.
One focus of current research efforts has been directed toward incorporating a comprehensive thermal analysis modeling capability. Typically, temperature affects the behavior of smart materials by three distinct mechanisms:
Previous analytical models only investigated the first two thermal effects mechanisms. However, since the material properties of piezoelectric materials generally vary greatly with temperature (see the graph), incorporating temperature-dependent material properties will significantly affect the structural deflections, sensory voltages, and stresses.
Thus, the current analytical model captures thermal effects arising from all three mechanisms through thermopiezoelectric constitutive equations. These constitutive equations were incorporated into a layerwise laminate theory with the inherent capability to model both the active and sensory response of smart structures in thermal environments. Corresponding finite element equations were formulated and implemented for both the beam and plate elements to provide a comprehensive thermal effects modeling capability.
Lee, H.-J.; and Saravanos, D.A.: The Effect of Temperature Induced
Material Property Variations on Piezoelectric Composite Plates.
AIAA Paper 97-1355, 1997.
Lee, H.-J.; and Saravanos, D.A.: A Review of Smart Structures
Modeling Activities. HITEMP Review 1997. NASA CP-10192, 1997,
paper 37, pp. 1-10. (Permission to cite this material was granted
by Carol A. Ginty, February 19, 1998.)
Lee, H.-J.; and Saravanos, D.A.: Thermal Shape Control of Active and Sensory Piezoelectric Composite Plates. Analysis and Design Issues for Modern Aerospace Vehicles 1997. ASME AD-Vol. 55, 1997.
Lewis contacts: Ho-Jun Lee, (216) 433-3316,
Ho-Jun.Lee@grc.nasa.gov,
and Dale A. Hopkins, (216) 433-3260,
Dale.A.Hopkins@grc.nasa.gov
Ohio Aerospace Institute contact: Dimitrios A. Saravanos,
Dimitrios.A.Saravanos@grc.nasa.gov
Author: Ho-Jun Lee
Headquarters program office: OASTT
Programs/Projects: Propulsion Systems R&T, HITEMP
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