Andrew Lee

Dissertation Committee:
Professor Daniel J. Inman, Chair
Professor Henry A. Sodano, Member
Associate Professor Veera Sundararaghavan, Member
Professor Kon-Well Wang, Cognate Member

Presentation Information:
Date: Monday, May 27, 2019
Time: 8:00 AM
Location: FXB-1044 (McDivitt Conference Room, FXB)

Elastic instabilities associated with buckling in multistable structures have been harnessed toward energy-based and control-based applications, with significant research toward energy harvesting and morphing. Often combined with smart materials such as piezoelectric or shape memory alloy actuators, bistable composite plates are popular host structures due to maintaining two geometrically distinct stable shapes without any external influence. A second potential well is traditionally generated from anisotropic thermal residual stresses in fiber-reinforced composite laminates during cure cycle cooldown. In this work, a novel method of inducing bistability is investigated by bonding two piezoelectrically actuated Macro Fiber Composites (MFC) in a cross-ply layup and releasing the voltage post cure to yield two cylindrically stable configurations. Since the MFCs are simultaneously the transducer and host structure, the resulting efficiencies and increase in actuation authority enable multifunctionality while exceeding the limits of conventional bistable prototypes that are designed with a single application in mind. Through MFC actuation, quasi-static snap through morphing is achieved with no external assistance while unwanted cross-well instabilities resulting from nonlinear vibrations are suppressed with active control strategies. The same cross-well dynamics are also exploited in various broadband energy harvesting applications.