Synergistic smart morphing aileron: Experimental quasi-static performance characterization

Abstract

This article describes the development and characterization of the synergistic smart morphing aileron concept, which leverages the properties of two different smart material actuators to achieve performance that exceeds that of the constituent materials. Utilizing the relatively higher work density and phase transformation of shape memory alloys combined with the larger bandwidth and conformal bending of bonded piezoelectric macro-fiber composites, the resultant synergistic morphing design improves the range of static tip deflections, enabling the capability to hold more trim positions over long timescales while still quickly compensating for dynamic loading. By commanding an input of full-range square waves of 0.01-10 Hz to the actuators, first-order time responses were measured and characterized using a common methodology by tracking a relative time constant. Using this method, aeroelastic effects for each actuator and the combined system were characterized in a wind tunnel at 0°angle of attack with flow speeds ranging from 0 to 15 m/s. This novel approach characterized a large-deflection morphing actuation system with multiple smart materials operating over different timescales. The combined system achieved additive amplitude while tracking the faster actuation response of the macro-fiber composite between 0.1 and 1 Hz.

Dynamics of a hybrid morphing wing with active open loop vibrating trailing edge by time-resolved PIV and force measures

“…A combination of both SMAs and LZT can enhance significantly the global performance. The synergistic smart morphing aileron (Pankonien et al, 2015) is the combination of a SMA actuated hinge followed by a flexible piezoelectric driven trailing edge.…”

Synergistic Smart Morphing AIleron: Capabilites Identification

“…Previous analysis of the trailing edge deflections of the SSMA concept showed that the primary quasi-static gains of the SSMA concept occurred between 0.1 -1 Hz, which corresponded to the gap between the rise in the relative time constant of the trailing edge deflection for the constituent actuators 10 . Although this result implied that the aerodynamic gains could also be augmented within this frequency range, the modeled first-order actuation initially resembled a step-response.…”

“…The results concluded that both smart material systems could be initially characterized by measuring the response to a square wave input of a relevant period. For initial investigation, the effect of both smart material subsystems on the deflection of the trailing edge was assumed to be a first order system with a step input response of infinite period, of the form: ( 1 ) where δ was the trailing edge displacement of the tip of the morphing aileron if everything else was held constant, δ i the initial trailing edge position of the morphing aileron, δ f was the final (desired) displacement, and τ ∞ was the firstorder time constant of the system response from Pankonien et al 10 . Assuming that both of the initial and final positions were within the upper, δ u , and lower, δ l , bounds of the actuator, the response of the form: ( 2 ) where Δ was the difference between the current position and the respective bound of the actuator in the direction of the desired actuation.…”

Stall Recovery of a Morphing Wing via Extended Nonlinear Lifting-Line Theory

“…In actuating the SMA and MFC in opposite directions, the airfoil experiences reflex camber. Pankonien and Inman have shown that a morphing airfoil composed of an MFC trailing edge with anterior SMA hinge in reflex can achieve the same lift as an airfoil with monotonic actuation while maintaining attached flow [24]. Thus, a single improvement to existing morphing designs, a continuous morphing hinge in addition to the camber morphing control surface, is suggested for future morphing aircraft designs with an emphasis on broad-range stall recovery.…”