TY - GEN
T1 - Adaptive and compliant wingtip devices enabled by additive manufacturing and multistable structures
AU - Gustafson, Kimberly
AU - Urrutia, Luis
AU - Pankonien, Alexander
AU - Reich, Gregory
AU - Wissa, Aimy
N1 - Publisher Copyright:
© 2019 SPIE.
PY - 2019
Y1 - 2019
N2 - Multifunctional lifting surfaces can expand the mission capabilities of aerial vehicles with a minimal number of components added to the vehicle. This paper presents a bio-inspired segmented wingtip concept for lift enhancement enabled by passive structural tailoring and active bistable truss mechanisms. The development of wingtips stems from studies of birds with desirable flight capabilities. The structural characteristics and maneuverable changes of a bird's primary feathers during flight have identified three notable feather degrees of freedom: incidence angle, dihedral angle, and gap spacing. Wind tunnel experiments conducted on multi-wingtip systems have determined that different wingtip orientations and spacings are desired to enhance aerodynamic performance depending on the flight conditions. These results suggest that the wingtip degrees of freedom must be varied during flight to achieve optimal aerodynamic performance. This paper presents two structural concepts, one passive and one active, to achieve desired morphological wingtip parameters during flight. The passive structural concept exploits bend-twist coupling of additively manufactured composite laminate wingtips by using aerodynamic loads to induce passive shape adaptation of the composite wingtips to control the twist and dihedral angles. The active concept utilizes bistable truss mechanisms to vary the wingtip gap spacing. The force-displacement responses of bistable mechanisms and the bending and twist of bend-twist coupled composite wingtips are measured using a universal testing machine and Digital Image Correlation, respectively. Experimental results include the energy storage characterization of the bistable mechanisms as a function of material characteristics and the bend-twist coupling of the composite wingtips as a function of fabrication process and laminate properties.
AB - Multifunctional lifting surfaces can expand the mission capabilities of aerial vehicles with a minimal number of components added to the vehicle. This paper presents a bio-inspired segmented wingtip concept for lift enhancement enabled by passive structural tailoring and active bistable truss mechanisms. The development of wingtips stems from studies of birds with desirable flight capabilities. The structural characteristics and maneuverable changes of a bird's primary feathers during flight have identified three notable feather degrees of freedom: incidence angle, dihedral angle, and gap spacing. Wind tunnel experiments conducted on multi-wingtip systems have determined that different wingtip orientations and spacings are desired to enhance aerodynamic performance depending on the flight conditions. These results suggest that the wingtip degrees of freedom must be varied during flight to achieve optimal aerodynamic performance. This paper presents two structural concepts, one passive and one active, to achieve desired morphological wingtip parameters during flight. The passive structural concept exploits bend-twist coupling of additively manufactured composite laminate wingtips by using aerodynamic loads to induce passive shape adaptation of the composite wingtips to control the twist and dihedral angles. The active concept utilizes bistable truss mechanisms to vary the wingtip gap spacing. The force-displacement responses of bistable mechanisms and the bending and twist of bend-twist coupled composite wingtips are measured using a universal testing machine and Digital Image Correlation, respectively. Experimental results include the energy storage characterization of the bistable mechanisms as a function of material characteristics and the bend-twist coupling of the composite wingtips as a function of fabrication process and laminate properties.
KW - Angle between the span of the base wing and the span of a wingtip
KW - Chordwise distance between wingtips expressed as a percent of the base wing chord length
KW - Wingtip angle of attack relative to the base wing angle of attack
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U2 - 10.1117/12.2514197
DO - 10.1117/12.2514197
M3 - Conference contribution
AN - SCOPUS:85069766729
T3 - Proceedings of SPIE - The International Society for Optical Engineering
BT - Bioinspiration, Biomimetics, and Bioreplication IX
A2 - Martin-Palma, Raul J.
A2 - Knez, Mato
A2 - Lakhtakia, Akhlesh
PB - SPIE
T2 - Bioinspiration, Biomimetics, and Bioreplication IX 2019
Y2 - 4 March 2019 through 5 March 2019
ER -