A Preliminary Study on Piezo-aeroelastic Energy Harvesting Using a Nonlinear Trailing-Edge Flap

배재성,Daniel J. Inman 한국항공우주학회 2015 International Journal of Aeronautical and Space Sc Vol.16 No.3

Recently, piezo-aeroelastic energy harvesting has received greater attention. In the present study, a piezo-aeroelastic energy harvester using a nonlinear trailing-edge flap is proposed, and its nonlinear aeroelastic behaviors are investigated. The energy harvester is modeled using a piezo-aeroelastic model of a two-dimensional typical section airfoil with a trailing-edge flap (TEF). A piezo-aeroelastic analysis is carried out using RL and time-integration methods, and the results are verified with the experimental data. The linearizing method using a describing function is used for the frequency domain analysis of the nonlinear piezo-aeroelastic system. From the linear and nonlinear piezo-aeroelastic analysis, the limit cycle oscillation (LCO) characteristics of the proposed energy harvester with the nonlinear TEF are investigated in both the frequency and time domains. Finally, the authors discuss the air speed range for effective piezo-aeroelastic energy harvesting.

Active shape change of an SMA hybrid composite plate

Daghia, Federica,Inman, Daniel J.,Ubertini, Francesco,Viola, Erasmo Techno-Press 2010 Smart Structures and Systems, An International Jou Vol.6 No.2

An experimental study was carried out to investigate the shape control of plates via embedded shape memory alloy (SMA) wires. An extensive body of literature proposes the use of SMA wires to actively modify the shape or stiffness of a structure; in most cases, however, the study focuses on modeling and little experimental data is available. In this work, a simple proof of concept specimen was built by attaching four prestrained SMA wires to one side of a carbon fiber laminate plate strip. The specimen was clamped at one end and tested in an environmental chamber, measuring the tip displacement and the SMA temperature. At heating, actuation of the SMA wires bends the plate; at cooling deformation is partially recovered. The specimen was actuated a few times between two fixed temperatures $T_c$ and $T_h$, whereas in the last actuation a temperature $T_f$ > $T_h$ was reached. Contrary to most model predictions, in the first actuation the transformation temperatures are significantly higher than in the following cycles, which are stable. Moreover, if the temperature $T_h$ is exceeded, two separate actuations occur during heating: the first follows the path of the stable cycles; the second, starting at $T_h$, is similar to the first cycle. An interpretation of the phenomenon is given using some differential scanning calorimeter (DSC) measurements. The observed behavior emphasizes the need to build a more comprehensive constitutive model able to include these effects.

Wireless Structural Health Monitoring Using an Active Sensing Node

박승희,윤정방,Daniel J. Inman 한국강구조학회 2006 International Journal of Steel Structures Vol.6 No.5

The development of an active sensing node has brought the traditional impedance-based structural health monitoring (SHM)technique to a new paradigm. The active sensing node consists of a miniaturized impedance measuring device (AD5933), amicrocontroller (ATmega128L), and a radio frequency (RF) transmiter (XBee). A macro-fiber composite (MFC) patchincluding structural interrogation, data acquisition, signal procesing, and damage diagnostic is being performed at the sensorlocation by the microcontroller. The RF transmitter is used to comunicate the current status of the host structure. To validatethe feasibility of the proposed active sensor node, two kinds of example studies are carried out: (a) corosion detection on analuminum beam and (b) lose bolt inspection on a bolt-jointed structure.

Active shape change of an SMA hybrid composite plate

Federica Daghia,Daniel J. Inman,Francesco Ubertini,Erasmo Viola 국제구조공학회 2010 Smart Structures and Systems, An International Jou Vol.6 No.2

An experimental study was carried out to investigate the shape control of plates via embedded shape memory alloy (SMA) wires. An extensive body of literature proposes the use of SMA wires to actively modify the shape or stiffness of a structure; in most cases, however, the study focuses on modeling and little experimental data is available. In this work, a simple proof of concept specimen was built by attaching four prestrained SMA wires to one side of a carbon fiber laminate plate strip. The specimen was clamped at one end and tested in an environmental chamber, measuring the tip displacement and the SMA temperature. At heating, actuation of the SMA wires bends the plate; at cooling deformation is partially recovered. The specimen was actuated a few times between two fixed temperatures Tc and Th, whereas in the last actuation a temperature Tf > Th was reached. Contrary to most model predictions, in the first actuation the transformation temperatures are significantly higher than in the following cycles, which are stable. Moreover, if the temperature Th is exceeded, two separate actuations occur during heating: the first follows the path of the stable cycles; the second, starting at Th, is similar to the first cycle. An interpretation of the phenomenon is given using some differential scanning calorimeter (DSC) measurements. The observed behavior emphasizes the need to build a more comprehensive constitutive model able to include these effects.

A Preliminary Study on Piezo-aeroelastic Energy Harvesting Using a Nonlinear Trailing-Edge Flap

Bae, Jae-Sung,Inman, Daniel J. The Korean Society for Aeronautical and Space Scie 2015 International Journal of Aeronautical and Space Sc Vol.16 No.3

Recently, piezo-aeroelastic energy harvesting has received greater attention. In the present study, a piezo-aeroelastic energy harvester using a nonlinear trailing-edge flap is proposed, and its nonlinear aeroelastic behaviors are investigated. The energy harvester is modeled using a piezo-aeroelastic model of a two-dimensional typical section airfoil with a trailing-edge flap (TEF). A piezo-aeroelastic analysis is carried out using RL and time-integration methods, and the results are verified with the experimental data. The linearizing method using a describing function is used for the frequency domain analysis of the nonlinear piezo-aeroelastic system. From the linear and nonlinear piezo-aeroelastic analysis, the limit cycle oscillation (LCO) characteristics of the proposed energy harvester with the nonlinear TEF are investigated in both the frequency and time domains. Finally, the authors discuss the air speed range for effective piezo-aeroelastic energy harvesting.

Autonomous hardware development for impedance-based structural health monitoring

Grisso, Benjamin L.,Inman, Daniel J. Techno-Press 2008 Smart Structures and Systems, An International Jou Vol.4 No.3

The development of a digital signal processor based prototype is described in relation to continuing efforts for realizing a fully self-contained active sensor system utilizing impedance-based structural health monitoring. The impedance method utilizes a piezoelectric material bonded to the structure under observation to act as both an actuator and sensor. By monitoring the electrical impedance of the piezoelectric material, insights into the health of the structured can be inferred. The active sensing system detailed in this paper interrogates a structure utilizing a self-sensing actuator and a low cost impedance method. Here, all the data processing, storage, and analysis is performed at the sensor location. A wireless transmitter is used to communicate the current status of the structure. With this new low cost, field deployable impedance analyzer, reliance on traditional expensive, bulky, and power consuming impedance analyzers is no longer necessary. A complete power analysis of the prototype is performed to determine the validity of power harvesting being utilized for self-containment of the hardware. Experimental validation of the prototype on a representative structure is also performed and compared to traditional methods of damage detection.

Small-scale Piezoelectric Energy Harvesting Devices Using Low-energy-density Sources

Mickael Lallart,Shashank Priya,Daniel J. Inman,Scott Bressers 한국물리학회 2010 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.57 No.41

Over the last decade, small-scale energy harvesting devices that can power household electronic systems have experienced rapid development in both the research and the industrial fields. However, the large majority of work done in this domain still focuses on high-energy-density sources, which are not always available in the vicinity of the device. In that case, it is, therefore, important to use other sources, which, nevertheless, present lower energy densities. Hence, the purpose of this paper is to investigate such harvesting methods, highlighting their differences with classical techniques that rely on high-density energy resources. Additionally, the present study also aims at reviewing existing techniques for small-scale energy harvesting using piezoelectric devices, as well as presenting new designs when dealing with low energy density sources, with a particular focus on wind and rain.

Autonomous hardware development for impedance-based structural health monitoring

Benjamin L. Grisso,Daniel J. Inman 국제구조공학회 2008 Smart Structures and Systems, An International Jou Vol.4 No.3

The development of a digital signal processor based prototype is described in relation to continuing efforts for realizing a fully self-contained active sensor system utilizing impedance-based structural health monitoring. The impedance method utilizes a piezoelectric material bonded to the structure under observation to act as both an actuator and sensor. By monitoring the electrical impedance of the piezoelectric material, insights into the health of the structured can be inferred. The active sensing system detailed in this paper interrogates a structure utilizing a self-sensing actuator and a low cost impedance method. Here, all the data processing, storage, and analysis is performed at the sensor location. A wireless transmitter is used to communicate the current status of the structure. With this new low cost, field deployable impedance analyzer, reliance on traditional expensive, bulky, and power consuming impedance analyzers is no longer necessary. A complete power analysis of the prototype is performed to determine the validity of power harvesting being utilized for self-containment of the hardware. Experimental validation of the prototype on a representative structure is also performed and compared to traditional methods of damage detection.

Ultra low-power active wireless sensor for structural health monitoring

Zhou, Dao,Ha, Dong Sam,Inman, Daniel J. Techno-Press 2010 Smart Structures and Systems, An International Jou Vol.6 No.5

Structural Health Monitoring (SHM) is the science and technology of monitoring and assessing the condition of aerospace, civil and mechanical infrastructures using a sensing system integrated into the structure. Impedance-based SHM measures impedance of a structure using a PZT (Lead Zirconate Titanate) patch. This paper presents a low-power wireless autonomous and active SHM node called Autonomous SHM Sensor 2 (ASN-2), which is based on the impedance method. In this study, we incorporated three methods to save power. First, entire data processing is performed on-board, which minimizes radio transmission time. Considering that the radio of a wireless sensor node consumes the highest power among all modules, reduction of the transmission time saves substantial power. Second, a rectangular pulse train is used to excite a PZT patch instead of a sinusoidal wave. This eliminates a digital-to-analog converter and reduces the memory space. Third, ASN-2 senses the phase of the response signal instead of the magnitude. Sensing the phase of the signal eliminates an analog-to-digital converter and Fast Fourier Transform operation, which not only saves power, but also enables us to use a low-end low-power processor. Our SHM sensor node ASN-2 is implemented using a TI MSP430 microcontroller evaluation board. A cluster of ASN-2 nodes forms a wireless network. Each node wakes up at a predetermined interval, such as once in four hours, performs an SHM operation, reports the result to the central node wirelessly, and returns to sleep. The power consumption of our ASN-2 is 0.15 mW during the inactive mode and 18 mW during the active mode. Each SHM operation takes about 13 seconds to consume 236 mJ. When our ASN-2 operates once in every four hours, it is estimated to run for about 2.5 years with two AAA-size batteries ignoring the internal battery leakage.

Remote Impedance-based Loose Bolt Inspection Using a Radio-Frequency Active Sensing Node

Park, Seung-Hee,Yun, Chung-Bang,Inman, Daniel J. The Korean Society for Nondestructive Testing 2007 한국비파괴검사학회지 Vol.27 No.3

This paper introduces an active sensing node using radio-frequency (RF) telemetry. This device has brought the traditional impedance-based structural health monitoring (SHM) technique to a new paradigm. The RF active sensing node consists of a miniaturized impedance measuring device (AD5933), a microcontroller (ATmega128L), and a radio frequency (RF) transmitter (XBee). A macro-fiber composite (MFC) patch interrogates a host structure by using a self-sensing technique of the miniaturized impedance measuring device. All the process including structural interrogation, data acquisition, signal processing, and damage diagnostic is being performed at the sensor location by the microcontroller. The RF transmitter is used to communicate the current status of the host structure. The feasibility of the proposed SHM strategy is verified through an experimental study inspecting loose bolts in a bolt-jointed aluminum structure.