We investigate the fluid-structure interactions from distributed bleed flow control over a semispan wing. Multi-scale, constitutive models are developed to incorporate bleed-effected terms in both the stiffness and inertia terms. Extensive wind tunnel experiments investigate the behavior of the system under the presence of bleed in a variety of forms, such as the dynamic behavior from the natural forcing of the flow to different forms of bleed actuation and their effects on the dynamic response of the wing. As a result, we utilize this form of flow control to suppress undesired vibrations in open loop feedback form, as well as to define flutter control authority.

Magnetic based multiferroic antennas are superior to electrical antennas in dielectric-cluttered environments like the human body due to the electric signal from conventional antennas shorting in lossy environments while magnetic signals are free to propagate. In this work, we investigate a magnetic-based multiferroic embeddable antenna consisting of piezoelectric and magnetoelastic materials for inductively coupled communications within the human heart at 125 kHz. This presentation describes the analysis, fabrication, and testing of an axial extension mode multiferroic antenna. Dynamic mechanical, electrical, and magnet field strength testing data shows a promising new approach for communicating in dielectric-cluttered environments like the human anatomy.

Single frequency standing wave based ultrasonic imaging techniques have the advantage of enabling efficient laser scanning through high signal to noise ratio(SNR) compared to guided wave based ultrasonic imaging techniques. This paper describes a full field steady-state ultrasonic imaging techniques using a dual point laser scanning system. Traditional ultrasonic imaging systems use a mirror tilting device and single point laser doppler vibrometer(LDV) to measured the responses. After obtaining the steady-state responses, several wavenumber based damage detection algorithms are applied to detect structural damage. In this work, we develop a system that utilizes a dual point laser scanner to simultaneously measure the dual points of a structural response to reduce the interrogation time and to make the system applicable to multiple structure. To validate the proposed technique, experiments are conducted on plates with different thickness and defect sizes. The result show that the proposed technique could detect and qualify the various type of damage on the multiple structures with the improved speed.

The use of magnetoelectric based magnetometers as a rotary position and speed sensor when coupled with a magnetic encoder is investigated in this study. Such magnetometers typically operate at saturation to minimize jitter induced measurement errors. Magnetoelectric laminates fabricated with a high piezomagnetic coefficient magnetostrictive layer reach saturation at relatively low applied magnetic field levels. This makes magnetoelectric magnetometers appealing as rotary sensors from the standpoint of being able to mitigate jitter at a large standoff while possessing the additional benefit of passive operation. 2-2- configuration magnetoelectric laminates composed of Metglas and PZT5A were fabricated and magnetically characterized to demonstrate their rotary sensing capabilities.

This work concerns the modeling and analysis of nonlinear vibrations of thin structures with piezoelectric transduction. This type of structures is used in numerous applications and in particular for the design of micro-electro-mechanical systems (MEMS). This study proposes a numerical strategy to compute efficiently the dynamics of electromechanical problems with geometric non-linearities, i.e. by taking into account both piezoelectric coupling and large structural displacements. The methodology is based on the computation of independent Reduced-Order Models (ROM) obtained from full-order finite element solutions by using a modal projection technique and a non-intrusive STEP (STiffness Evaluation Procedure) approach.

As human life expectancy increases, more people suffer from neurodegenerative diseases at the late stage of their lives. Currently, millions of people are affected and there is still no cure. Our team studied ways to transport retinoic acid, a substance to promote neuronal survival and growth as current methods do not reach the target neurons in the required amount. We present an innovative magnetic helical microrobot (MHM) to transport superparamagnetic iron oxide nanoparticles. The analysis provides us relations of the geometric parameters to obtain an optimum translational speed. Our magnetic applicator to control the MHM is based on a tri-axial Helmholtz electromagnetic coil system.

Acoustic patterning and focusing is an interdisciplinary topic covering a wide range of applications. A particular challenge arises from the nonlinear distortion of the pressure waveforms that occurs at high acoustic intensities. Such a phenomenon, if not treated, limits the control of the sound field in the nonlinear range, reducing the localization and efficiency. In this work, we investigate acoustic holographic lenses for constructing precise nonlinear acoustic fields. Such passive structures provide higher fidelity at a fraction of the cost of the expensive and complex phased array transducers.

Fused deposition modeling permits rapid, low-cost fabrication of polymeric lattices. Frequently, these lattices are evaluated under isothermal conditions at ambient temperatures. However, the mechanical properties of polymeric lattices are sensitive to variations in temperature. We evaluate the mechanical behavior of polymeric lattices across a range of temperatures utilizing a coupled computational and experimental approach. 3D printed unit cells are subjected experimentally to sequential tension and compression and results are compared to a multiphysics finite element framework. Unit cells are then tessellated to form larger lattices that are analyzed computationally, wherein the effects of uniform and gradient temperatures are considered.

We investigate the extreme wave event in mechanical metamaterials composed of Triangulated Cylindrical Origami (TCO). Specifically, we focused on realizing rogue waves by employing a homogeneous one-dimensional chain constructed from the TCO unit cells. In association with data-driven methods, our numerical simulation suggests the wave focusing on a very limited number of unit cells, which can be potentially realized in the experimental setup. The mechanism of the wave localization using the TCO can be leveraged for efficient energy harvesting purposes in engineering applications.

We investigate a design method on tessellations of Tachi-Miura Polyhedron (TMP), origami-based auxetic mechanical metamaterials composed of bellows-like structures. In recent years, mechanical metamaterials have shown a significant amount of intriguing properties both statically and dynamically. In order to provide design tools for this class of metamaterials in a comparable way to the conventional materials, we utilize three-dimensional Ashby charts with Poisson’s ratio to visualize the mechanical properties. This three-dimensional Ashby chart emphasizes the advantage of origami metamaterials compared to conventional materials while maintaining the comparability of general mechanical properties. We analyze mechanical properties both analytically and experimentally. These methods can pave the way for the further utilization of advanced mechanical metamaterials.

Acoustic Power Transfer (APT) systems have gained interest in many engineering applications thanks to their superior efficiency and wireless connection when through-hole wiring is not an option. Although APT systems have been extensively studied in the last decades, the performance of such systems has not been yet optimized to achieve high efficiency or/and output power levels. In this paper, we consider the APT system consisting of a metal barrier sandwiched between two piezoelectric elements using epoxy as a coupling layer. Towards this, a three-dimensional propagation finite element model is developed and genetic algorithm-based optimization problem is formulated and implemented. The simulation results were compared against their experimental counterparts.