Experimental demonstration of active vibration and structural acoustic control using shape memory alloy (SMA) hybrid composites [C. A. Rogers, in Proceedings of the International Congress on Recent Developments in Air and Structure Borne Sound and Vibration (to be published)] has provided the motivation for investigating new control schemes and developing more accurate models. This paper will briefly describe newly developed constitutive models for shape memory alloy actuators and the hybrid material system. A general dynamical model for laminated SMA hybrid composite beams and plates will be presented with several theoretical results. A new structural acoustic model for laminated composite plates [Liang et al., J. Sound Vib. (to be published)] will be briefly described and the potential for active structural acoustic control using SMA hybrid composites demonstrated by numerical simulation.

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Modeling of shape memory alloy hybrid composites for structural acoustic control

Piezoelectric actuators are embedded in an idealized laminated composite wing structure that can adapt to changing flight conditions. A feedback control system senses wing roots strains and then applies a proportional voltage to active actuator layers to change wing lift or divergence dynamic pressure

Static aeroelastic control of an adaptive lifting surface

Fiber optic strain sensors for smart structures will have to provide broad dynamic range, high resolution, wide bandwidth, and in certain applications, absolute strain measurement. Different sensor...

Signal Processing Techniques for Interferometric Fiber-Optic Strain Sensors:

Vibration characteristics of hollow cantilevered beams containing an electro-rheological fluid

A digital signal processing algorithm, the moving reference line crossing count method (MRLCCM), was developed to implement the structural strain measurement by a passive demodulated fiber optic Michelson interferometric sensor. The fiber optic Michelson sensor, which is constructed of a 3 × 3 fiber optic coupler, can give information about the magnitude and direction of the strain of structures. The beating, drifting and noise, which are caused by the longitudinal strain and the lateral strain of the fiber, bring about the counting error of the phase differences which are directly converted to the structural strain. The developed algorithm is based on the reference line crossing count method and resets the reference line during the presence of the signal drifting. The accuracy of the strain calculation was confirmed by the various simulated fiber optic signals with signal beating, drifting and noise. A passive demodulated 3 × 3 fiber optic Michelson interferometric sensor was bonded on the cantilevered aluminum beam for experimental strain sensing. The capability of real-time processing was verified by the real fiber optic signals.

https://iopscience.iop.org/article/10.1088/0964-1726/8/4/301/pdf

R. G. May

Papers

Optical fiber sensors and signal processing for smart materials and structures applications